# Parser.pm: parse texinfo code into a tree.
#
# Copyright 2010-2019 Free Software Foundation, Inc.
# 
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License,
# or (at your option) any later version.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
# 
# Original author: Patrice Dumas <pertusus@free.fr>
# Parts (also from Patrice Dumas) come from texi2html.pl or texi2html.init.

# Note: This file may not be loaded if TEXINFO_XS_PARSER is set in the
# environment, due to a hook placed in @INC by Texinfo::ModulePath.

# The organization of the file is the following:
#  module definitions.
#  default parser state.  With explanation of the internal structures.
#  initializations, determination of command types.
#  user visible subroutines.
#  internal subroutines, doing the parsing.

package Texinfo::Parser;

# We need the unicode stuff.
use 5.006;
use strict;

# debug
use Carp qw(cluck);

use Data::Dumper;

# to detect if an encoding may be used to open the files
use Encode;

# for fileparse
use File::Basename;

# Clone could be faster for small structures, which should be the case
# here, but Clone is not in perl core modules, so we use Storable::dclone.
use Storable qw(dclone); # standard in 5.007003

# commands definitions
use Texinfo::Common;
# Error reporting and counting, translation of strings.
use Texinfo::Report;
# encoding_alias
use Texinfo::Encoding;

# to normalize node name, anchor, float arg, and first *ref argument.
use Texinfo::Convert::NodeNameNormalization;
# in error messages, and for macro body expansion
use Texinfo::Convert::Texinfo;

require Exporter;
use vars qw($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);
@ISA = qw(Exporter Texinfo::Report);

our $module_loaded = 0;
sub import {
  if (!$module_loaded) {
    Texinfo::XSLoader::override ("Texinfo::Parser::_merge_text",
      "Texinfo::MiscXS::merge_text");
    Texinfo::XSLoader::override ("Texinfo::Parser::_abort_empty_line",
      "Texinfo::MiscXS::abort_empty_line");
    Texinfo::XSLoader::override ("Texinfo::Parser::_parse_texi_regex",
      "Texinfo::MiscXS::parse_texi_regex");
    $module_loaded = 1;
  }
  # The usual import method
  goto &Exporter::import;
}


%EXPORT_TAGS = ( 'all' => [ qw(
  parser
  parse_texi_text
  parse_texi_line
  parse_texi_file
  indices_information
  floats_information
  internal_references_information
  labels_information
  global_commands_information
  global_informations
) ] );

@EXPORT_OK = ( @{ $EXPORT_TAGS{'all'} } );

@EXPORT = qw(
);

$VERSION = '6.6.90';

sub N__($)
{
  return $_[0];
}

my %parser_default_configuration = (
    %Texinfo::Common::default_parser_state_configuration,
    %Texinfo::Common::default_customization_values);

# the other possible keys for the parser state are:
#
# expanded_formats_hash   each key comes from expanded_formats value is 1
# index_names             a structure holding the link between index 
#                         names, merged indices,
#                         initial value is %index_names in Texinfo::Common.
# context_stack           stack of the contexts, more recent on top.
#                         'line' is added when on a line or 
#                         block @-command line,
#                         'def' is added instead if on a definition line.
#                         'preformatted' is added in block commands 
#                         where there is no paragraphs and spaces are kept 
#                         (format, example, display...)
#                         'rawpreformatted' is added in raw block commands
#                         (html, xml, docbook...)
#                         'menu' is added in menu commands
#                         'math', 'footnote', 'caption', 'shortcaption', 
#                         'inlineraw' are also added when in those commands
# conditionals_stack      a stack of conditional commands that are expanded.
# macro_stack             stack of macros being expanded (more recent first)
# definfoenclose          an hash, key is the command name, value is an array
#                         reference with 2 values, beginning and ending.
# input                   a stack, with last at bottom.  Holds the opened files
#                         or text.  Pending macro expansion or text expansion
#                         is also in that structure.
# line_commands           the same as %line_commands in Texinfo::Common, 
#                         but with index entry commands dynamically added
# close_paragraph_commands      same as %close_paragraph_commands
# close_preformatted_commands   same as %close_preformatted_commands
# no_paragraph_commands   the same as %default_no_paragraph_commands
#                         below, with index
#                         entry commands dynamically added
# simple_text_commands    the same as %simple_text_commands below, but 
#                         with index entry commands dynamically added
# current_node            last seen node.
# current_section         last seen section.
# nodes                   list of nodes.
# command_index           associate a command name with an index name
# floats                  key is the normalized float type, value is an array
#                         reference holding all the floats.
# internal_references     an array holding all the internal references.

# set                     points to the value set when initializing, for
#                         configuration items that are not to be overriden
#                         by @-commands.  For example documentlanguage.

# A line information is an hash reference with the keys:
# line_nr        the line number
# file_name      the file name
# macro          if in a macro expansion, the name of the macro
#
# A text fragment information is a 2 element array reference, the first is the
# text fragment, the second is the line information.

# The input structure is an array, the first is the most recently included
# file.  The last element may be a file if the parsing is done on a file, 
# with parse_texi_file, or simply pending text, if called as parse_texi_text.
# each element of the array is a hash reference.  The key are:
# pending    an array reference containing pending text fragments, either the
#            text given as parse_texi_text or macro expansion text.
# name       file name
# line_nr    current line number in the file
# fh         filehandle for the file

# The commands in initialization_overrides are not set in the document if
# set at the parser initialization.
my %initialization_overrides = (
  'documentlanguage' => 1,
);

my %no_brace_commands         = %Texinfo::Common::no_brace_commands;
my %line_commands             = %Texinfo::Common::line_commands;
my %other_commands            = %Texinfo::Common::other_commands;
my %brace_commands            = %Texinfo::Common::brace_commands;    
my %accent_commands           = %Texinfo::Common::accent_commands;
my %context_brace_commands    = %Texinfo::Common::context_brace_commands;
my %block_commands            = %Texinfo::Common::block_commands;
my %block_item_commands       = %Texinfo::Common::block_item_commands;
my %close_paragraph_commands  = %Texinfo::Common::close_paragraph_commands;
my %def_map                   = %Texinfo::Common::def_map;
my %def_commands              = %Texinfo::Common::def_commands;
my %def_aliases               = %Texinfo::Common::def_aliases;
my %menu_commands             = %Texinfo::Common::menu_commands;
my %preformatted_commands     = %Texinfo::Common::preformatted_commands;
my %format_raw_commands = %Texinfo::Common::format_raw_commands;
my %item_container_commands   = %Texinfo::Common::item_container_commands;
my %item_line_commands        = %Texinfo::Common::item_line_commands;
my %deprecated_commands       = %Texinfo::Common::deprecated_commands;
my %root_commands             = %Texinfo::Common::root_commands;
my %sectioning_commands       = %Texinfo::Common::sectioning_commands;
my %command_index             = %Texinfo::Common::command_index;
my %ref_commands              = %Texinfo::Common::ref_commands;
my %region_commands           = %Texinfo::Common::region_commands;
my %code_style_commands       = %Texinfo::Common::code_style_commands;
my %in_heading_commands       = %Texinfo::Common::in_heading_commands;
my %in_index_commands         = %Texinfo::Common::in_index_commands;
my %explained_commands        = %Texinfo::Common::explained_commands;
my %inline_format_commands    = %Texinfo::Common::inline_format_commands;
my %inline_commands           = %Texinfo::Common::inline_commands;
my %inline_conditional_commands = %Texinfo::Common::inline_conditional_commands;
my %all_commands              = %Texinfo::Common::all_commands;

# equivalence between a @set flag and an @@-command
my %set_flag_command_equivalent = (
  'txicodequoteundirected' => 'codequoteundirected',
  'txicodequotebacktick'   => 'codequotebacktick',
#  'txideftypefnnl'         => 'deftypefnnewline',
);


# keep line information for those commands.
my %keep_line_nr_brace_commands = %context_brace_commands;
foreach my $keep_line_nr_brace_command ('titlefont', 'anchor') {
  $keep_line_nr_brace_commands{$keep_line_nr_brace_command} = 1;
}
foreach my $brace_command (keys (%brace_commands)) {
  $keep_line_nr_brace_commands{$brace_command} = 1;
}

my %type_with_paragraph;
foreach my $type ('before_item', 'text_root', 'document_root',
                  'brace_command_context') {
  $type_with_paragraph{$type} = 1;
}

my %command_ignore_space_after;
foreach my $command ('anchor', 'hyphenation', 'caption', 'shortcaption',
                     'sortas', 'seeentry', 'seealso') {
  $command_ignore_space_after{$command} = 1;
}

my %global_multiple_commands;
foreach my $global_multiple_command (
  'footnote', 'hyphenation', 'insertcopying', 'printindex',
  'subtitle','titlefont', 'listoffloats', 'detailmenu', 'part',
  keys(%Texinfo::Common::document_settable_at_commands), ) {
  $global_multiple_commands{$global_multiple_command} = 1;
}

my %global_unique_commands;
foreach my $global_unique_command (
  'copying', 'settitle', 
  'shorttitlepage', 'title', 'titlepage', 'top', 
  keys(%Texinfo::Common::document_settable_unique_at_commands), ) {
  $global_unique_commands{$global_unique_command} = 1;
}

my %index_names = %Texinfo::Common::index_names;

# index names that cannot be set by the user.
my %forbidden_index_name = ();

foreach my $name (keys(%index_names)) {
  $forbidden_index_name{$name} = 1;
  if ($name =~ /^(.).$/) {
    $forbidden_index_name{$1} = 1;
  }
}

foreach my $other_forbidden_index_name ('info','ps','pdf','htm',
   'html', 'log','aux','dvi','texi','txi','texinfo','tex','bib') {
  $forbidden_index_name{$other_forbidden_index_name} = 1;
}

# @-commands that do not start a paragraph
my %default_no_paragraph_commands;
# @-commands that should be at the beginning of a line
my %begin_line_commands;

foreach my $command ('node', 'end') {
  $begin_line_commands{$command} = $command;
}

foreach my $no_paragraph_command ('titlefont', 'caption', 'shortcaption', 
          'image', '*', 'hyphenation', 'anchor', 'errormsg') {
  $default_no_paragraph_commands{$no_paragraph_command} = 1;
}

foreach my $no_paragraph_command (keys(%line_commands),
                                  keys(%other_commands)) {
  $default_no_paragraph_commands{$no_paragraph_command} = 1;
}

foreach my $no_paragraph_command (keys(%line_commands)) {
  $begin_line_commands{$no_paragraph_command} = 1;
}

# verbatiminclude is not said to begin at the beginning of the line
# in the manual
foreach my $not_begin_line_command ('comment', 'c', 'sp', 'columnfractions',
                                 'item', 'verbatiminclude',
                                 'set', 'clear', 'vskip', 'subentry') {
  delete $begin_line_commands{$not_begin_line_command};
}

my %block_arg_commands;
foreach my $block_command (keys(%block_commands)) {
  $begin_line_commands{$block_command} = 1;
  $default_no_paragraph_commands{$block_command} = 1;
  $block_arg_commands{$block_command} = 1 
    if ($block_commands{$block_command} ne 'raw');
#        and ! $format_raw_commands{$block_command});
}

my %close_preformatted_commands = %close_paragraph_commands;
foreach my $no_close_preformatted('sp') {
  delete $close_preformatted_commands{$no_close_preformatted};
}
# FIXME to close preformated or not to close?
#foreach my $format_raw_command(keys(%format_raw_commands)) {
#  $close_preformatted_commands{$format_raw_command} = 1;
#}

# commands that may appear in accents
my %in_accent_commands = %accent_commands;
foreach my $brace_command(keys(%brace_commands)) {
  $in_accent_commands{$brace_command} = 1 if (!$brace_commands{$brace_command});
}
foreach my $no_brace_command (keys(%no_brace_commands)) {
  $in_accent_commands{$no_brace_command} = 1;
}
$in_accent_commands{'c'} = 1;
$in_accent_commands{'comment'} = 1;

# commands that may appear in text arguments
my %in_full_text_commands;
foreach my $command (keys(%brace_commands), keys(%no_brace_commands)) {
  $in_full_text_commands{$command} = 1;
}
foreach my $in_full_text_command ('c', 'comment', 'refill', 'subentry',
                         'columnfractions', 'set', 'clear', 'end') {
  $in_full_text_commands{$in_full_text_command} = 1;
}

foreach my $out_format (keys(%format_raw_commands)) {
  $in_full_text_commands{$out_format} = 1;
}
delete $in_full_text_commands{'caption'};
delete $in_full_text_commands{'shortcaption'};
foreach my $block_command (keys(%block_commands)) {
  $in_full_text_commands{$block_command} = 1 
    if ($block_commands{$block_command} eq 'conditional');
}


# commands that may appear inside sectioning commands 
my %in_full_line_commands_no_refs = %in_full_text_commands;
foreach my $not_in_full_line_commands_no_refs ('titlefont', 
                                   'anchor', 'footnote', 'verb') {
  delete $in_full_line_commands_no_refs{$not_in_full_line_commands_no_refs};
}

# commands that may happen in simple text arguments
my %in_simple_text_commands = %in_full_line_commands_no_refs;
foreach my $not_in_simple_text_command('xref', 'ref', 'pxref', 'inforef') {
  delete $in_simple_text_commands{$not_in_simple_text_command};
}

# commands that only accept simple text as argument in any context.
my %simple_text_commands;
foreach my $line_command(keys(%line_commands)) {
  if ($line_commands{$line_command} =~ /^\d+$/ 
      or ($line_commands{$line_command} eq 'line' 
          and !($sectioning_commands{$line_command}
                or $def_commands{$line_command}))
      or $line_commands{$line_command} eq 'text') {
    $simple_text_commands{$line_command} = 1;
  }
}

my %full_line_commands_no_refs = (%sectioning_commands,
                                  %def_commands);

delete $simple_text_commands{'center'};
delete $simple_text_commands{'exdent'};

foreach my $command (keys (%brace_commands)) {
  if ($brace_commands{$command} =~ /\d/
      and $brace_commands{$command} > 0
      and !$inline_conditional_commands{$command}) {
    $simple_text_commands{$command} = 1;
  }
}

foreach my $command ('shortcaption', 'math') {
  $simple_text_commands{$command} = 1;
}

# commands that accept full text, but no block or top-level commands
my %full_text_commands;
foreach my $brace_command (keys (%brace_commands)) {  
  if ($brace_commands{$brace_command} eq 'style') {
    $full_text_commands{$brace_command} = 1;
  }
}

# commands that accept almost the same as in full text, except
# what does not make sense on a line.
my %full_line_commands;
$full_line_commands{'center'} = 1;
$full_line_commands{'exdent'} = 1;
$full_line_commands{'item'} = 1;
$full_line_commands{'itemx'} = 1;

# Fill the valid nestings hash.  The keys are the containing commands and
# the values arrays of commands that are allowed to occur inside those
# commands. All commands not in this hash are considered to accept anything.
# There are additional context tests, to make sure, for instance that we are 
# testing @-commands on the block, line or node @-command line and not
# in the content.
# Index entry commands are dynamically set as %in_simple_text_commands
my %default_valid_nestings;

foreach my $command (keys(%accent_commands)) {
  $default_valid_nestings{$command} = \%in_accent_commands;
}
foreach my $command (keys(%simple_text_commands)) {
  $default_valid_nestings{$command} = \%in_simple_text_commands;
}
foreach my $command (keys(%full_text_commands), keys(%full_line_commands)) {
  $default_valid_nestings{$command} = \%in_full_text_commands;
}
foreach my $command (keys(%full_line_commands_no_refs)) {
  $default_valid_nestings{$command} = \%in_full_line_commands_no_refs;
}

# Only for block commands with line arguments
foreach my $command (keys(%block_commands)) {
  if ($block_commands{$command} and $block_commands{$command} ne 'raw'
      and $block_commands{$command} ne 'conditional'
      and !$def_commands{$command}) {
    $default_valid_nestings{$command} = \%in_simple_text_commands;
  }
}


my @preformatted_contexts = ('preformatted', 'rawpreformatted');
my %preformatted_contexts;
foreach my $preformatted_context (@preformatted_contexts) {
  $preformatted_contexts{$preformatted_context} = 1;
}

# contexts on the context_stack stack where empty line doesn't trigger
# a paragraph
my %no_paragraph_contexts;
foreach my $no_paragraph_context ('math', 'menu', @preformatted_contexts, 
                                  'def', 'inlineraw') {
  $no_paragraph_contexts{$no_paragraph_context} = 1;
};



# Format a bug message
sub _bug_message($$;$$)
{
  my ($self, $message, $line_number, $current) = @_;

  my $line_message = '';
  if ($line_number) {
    my $file = $line_number->{'file_name'};
    $line_message 
      = "last location: $line_number->{'file_name'}:$line_number->{'line_nr'}";
    if ($line_number->{'macro'} ne '') {
      $line_message .= " (possibly involving $line_number->{'macro'})";
    }
    $line_message .= "\n";
  }
  my $message_context_stack = "context_stack: (@{$self->{'context_stack'}})\n";
  my $current_element_message = '';
  if ($current) {
    $current_element_message = "current: ". _print_current($current);
  }
  warn "You found a bug: $message\n\n".
       "Additional informations:\n".
       $line_message.$message_context_stack.$current_element_message;
}

# simple deep copy of a structure
# NOTE: currently not used, dclone is used instead.  But in case dclone 
# happens not to be enough in the future, _deep_copy could be reused.
sub _deep_copy($)
{
  my $struct = shift;
  my $string = Data::Dumper->Dump([$struct], ['struct']);
  eval $string;
  return $struct;
}

sub _setup_conf($$$)
{
  my ($parser, $conf, $module_name) = @_;

  if (defined($conf)) {
    foreach my $key (keys(%$conf)) {
      if (exists($parser_default_configuration{$key})) {
        if ($key ne 'values' and ref($conf->{$key})) {
          $parser->{$key} = dclone($conf->{$key});
        } else {
          $parser->{$key} = $conf->{$key};
        }
        if ($initialization_overrides{$key}) {
          $parser->{'set'}->{$key} = $parser->{$key};
        }
      } else {
        warn "$key not a possible customization in $module_name\n";
      }
    }
  }
}

# initialization entry point.  Set up a parser.
# The last argument, optional, is a hash provided by the user to change
# the default values for what is present in %parser_default_configuration.
sub parser(;$$)
{
  my $conf = shift;

  my $parser = dclone(\%parser_default_configuration);
  bless $parser;

  return _setup_parser($parser, $conf);
}

sub _setup_parser {
  my ($parser, $conf) = @_;

  _setup_conf($parser, $conf, "Texinfo::Parser::parser");

  # Now initialize command hash that are dynamically modified, notably
  # those for index commands, and lists, based on defaults and user provided.
  $parser->{'line_commands'} = dclone(\%line_commands);
  $parser->{'valid_nestings'} = dclone(\%default_valid_nestings);
  $parser->{'no_paragraph_commands'} = { %default_no_paragraph_commands };
  $parser->{'index_names'} = dclone(\%index_names);
  $parser->{'command_index'} = {%command_index};
  $parser->{'close_paragraph_commands'} = {%close_paragraph_commands};
  $parser->{'close_preformatted_commands'} = {%close_preformatted_commands};
  # a hash is simply concatenated.  It should be like %index_names.
  if (ref($parser->{'indices'}) eq 'HASH') {
    %{$parser->{'index_names'}} = (%{$parser->{'index_names'}}, 
                                   %{$parser->{'indices'}});
  } else { # an array holds index names defined with @defindex
    foreach my $name (@{$parser->{'indices'}}) {
      $parser->{'index_names'}->{$name} = {'in_code' => 0};
    }
  }
  foreach my $index (keys (%{$parser->{'index_names'}})) {
    if (!exists($parser->{'index_names'}->{$index}->{'name'})) {
      $parser->{'index_names'}->{$index}->{'name'} = $index;
    }
    if (!exists($parser->{'index_names'}->{$index}->{'contained_indices'})) {
      $parser->{'index_names'}->{$index}->{'contained_indices'}->{$index} = 1;
    }
    foreach my $prefix ($index, substr($index, 0, 1)) {
      $parser->{'line_commands'}->{$prefix.'index'} = 'line';
      $parser->{'no_paragraph_commands'}->{$prefix.'index'} = 1;
      $parser->{'valid_nestings'}->{$prefix.'index'} = \%in_simple_text_commands;
      $parser->{'command_index'}->{$prefix.'index'} = $index;
    }
  }
  if ($parser->{'merged_indices'}) {
    foreach my $index_from (keys (%{$parser->{'merged_indices'}})) {
      my $index_to = $parser->{'merged_indices'}->{$index_from};
      if (defined($parser->{'index_names'}->{$index_from})
          and defined($parser->{'index_names'}->{$index_to})) {
        $parser->{'index_names'}->{$index_from}->{'merged_in'} = $index_to;
        $parser->{'index_names'}->{$index_to}->{'contained_indices'}->{$index_from} = 1;
      }
    }
  }
  foreach my $explained_command(keys(%explained_commands)) {
    if  (!defined($parser->{'explained_commands'}->{$explained_command})) {
      $parser->{'explained_commands'}->{$explained_command} = {};
    }
  }
  $parser->{'context_stack'} = [ '_root' ];
  $parser->{'regions_stack'} = [];
  $parser->{'macro_stack'} = [];
  $parser->{'conditionals_stack'} = [];

  # turn the array to a hash for speed.  Not sure it really matters for such
  # a small array.
  foreach my $expanded_format(@{$parser->{'expanded_formats'}}) {
    $parser->{'expanded_formats_hash'}->{$expanded_format} = 1;
  }

  %{$parser->{'global_commands'}} = %global_multiple_commands;

  $parser->Texinfo::Report::new;

  return $parser;
}

# simple parser initialization, fit for strings of Texinfo, not whole 
# documents, targetting speed.
# all the simple_parsers share the dynamic informations
my $simple_parser_line_commands = dclone(\%line_commands);
my $simple_parser_valid_nestings = dclone(\%default_valid_nestings);
my $simple_parser_no_paragraph_commands = { %default_no_paragraph_commands };
my $simple_parser_index_names = dclone(\%index_names);
my $simple_parser_command_index = {%command_index};
my $simple_parser_close_paragraph_commands = {%close_paragraph_commands};
my $simple_parser_close_preformatted_commands = {%close_preformatted_commands};
sub simple_parser(;$)
{
  my $conf = shift;

  my $parser = dclone(\%parser_default_configuration);
  bless $parser;

  _setup_conf($parser, $conf, "Texinfo::Parser::simple_parser");

  $parser->{'line_commands'} = $simple_parser_line_commands;
  $parser->{'valid_nestings'} = $simple_parser_valid_nestings;
  $parser->{'no_paragraph_commands'} = $simple_parser_no_paragraph_commands;
  $parser->{'index_names'} = $simple_parser_index_names;
  $parser->{'command_index'} = $simple_parser_command_index;
  $parser->{'close_paragraph_commands'} = $simple_parser_close_paragraph_commands;
  $parser->{'close_preformatted_commands'} = $simple_parser_close_preformatted_commands;

  foreach my $explained_command(keys(%explained_commands)) {
    if  (!defined($parser->{'explained_commands'}->{$explained_command})) {
      $parser->{'explained_commands'}->{$explained_command} = {};
    }
  }
  $parser->{'context_stack'} = [ '_root' ];
  $parser->{'regions_stack'} = [];
  $parser->{'macro_stack'} = [];
  $parser->{'conditionals_stack'} = [];

  # turn the array to a hash for speed.  Not sure it really matters for such
  # a small array.
  foreach my $expanded_format(@{$parser->{'expanded_formats'}}) {
    $parser->{'expanded_formats_hash'}->{$expanded_format} = 1;
  }

  %{$parser->{'global_commands'}} = ();

  $parser->Texinfo::Report::new;

  return $parser;
}

sub get_conf($$)
{
  my ($self, $var) = @_;
  return $self->{$var};
}

# split a scalar text in an array lines.
sub _text_to_lines($)
{
  my $text = shift;
  die if (!defined($text));
  my $had_final_end_line = chomp($text);
  my $lines = [ map {$_."\n"} split (/\n/, $text, -1) ];
  chomp($lines->[-1]) unless (!@$lines or $had_final_end_line);
  return $lines;
}

# construct a text fragments array matching a lines array, based on information
# supplied.
# If $fixed_line_number is set the line number is not increased, otherwise
# it is increased, beginning at $first_line.
sub _complete_line_nr($$;$$$)
{
  my ($lines, $first_line, $file, $macro, $fixed_line_number) = @_;

  $macro = '' if (!defined($macro));
  $file = '' if (!defined($file));
  my $new_lines = [];

  if (defined($first_line)) {
    my $line_index = $first_line;
    foreach my $index(0..scalar(@$lines)-1) {
      $line_index = $index+$first_line if (!$fixed_line_number);
      $new_lines->[$index] = [ $lines->[$index],  
                             { 'line_nr' => $line_index,
                               'file_name' => $file, 'macro' => $macro } ];
    }
  } else {
    foreach my $line (@$lines) {
      push @$new_lines, [ $line ];
    }
  }
  return $new_lines;
}

# entry point for text fragments.
# Used in tests.
# Note that it has no associated root type a opposed to parse_texi_line
# and parse_texi_file.
sub parse_texi_text($$;$$$$)
{
  my ($self, $text, $lines_nr, $file, $macro, $fixed_line_number) = @_;

  return undef if (!defined($text));

  my $lines_array = [];
  if (!ref($text)) {
    $text = _text_to_lines($text);
  }
  $lines_nr = [] if (!defined($lines_nr));
  if (!ref($lines_nr)) {
    #$file =~ s/^.*\/// if (defined($file) and $self->{'TEST'});
    $lines_array = _complete_line_nr($text, $lines_nr, $file, 
                                     $macro, $fixed_line_number);
  } else {
    while (@$text) {
      my $line_nr = shift @$lines_nr;
      my $line = shift @$text;
      push @$lines_array, [$line, $line_nr];
    }
  }

  $self = parser() if (!defined($self));
  $self->{'input'} = [{'pending' => $lines_array}];
  my $tree = $self->_parse_texi();
  return $tree;
}

sub _open_in {
  my ($self, $filehandle, $file_name) = @_;

  if (open($filehandle, $file_name)) {
    if (defined($self->{'info'}->{'input_perl_encoding'})) {
      if ($self->{'info'}->{'input_perl_encoding'} eq 'utf-8') {
        binmode($filehandle, ":utf8");
      } else {
        binmode($filehandle, ":encoding($self->{'info'}->{'input_perl_encoding'})");
        # For UTF-8, this would lead to errors in Latin-1 input the first time 
        # a line is read from the file, even though the binmode is changed 
        # later.  Evidently Perl is checking ahead in the file to see if the 
        # input is valid.
      }
    }
    return 1;
  } else {
    return 0;
  }
}

# parse a texi file
sub parse_texi_file($$)
{
  my ($self, $file_name) = @_;

  my $filehandle = do { local *FH };
  if (!_open_in($self, $filehandle, $file_name)) {
    $self->document_error(sprintf(__("could not open %s: %s"), 
                                  $file_name, $!));
    return undef;
  }
  my $line_nr = 0;
  my $line;
  my @first_lines;

  my $pending_first_texi_line;
  # the first line not empty and not with \input is kept in 
  # $pending_first_texi_line and put in the pending lines just below
  while ($line = <$filehandle>) {
    $line_nr++;
    if ($line =~ /^ *\\input/ or $line =~ /^\s*$/) {
      $line =~ s/\x{7F}.*\s*//;
      push @first_lines, $line;
    } else {
      $pending_first_texi_line = $line;
      last;
    }
  }
  my $root = { 'contents' => [], 'type' => 'text_root' };
  if (@first_lines) {
    push @{$root->{'contents'}}, { 'type' => 'preamble', 'contents' => [],
                                   'parent' => $root };
    foreach my $line (@first_lines) {
      push @{$root->{'contents'}->[-1]->{'contents'}}, 
                                   { 'text' => $line,
                                     'type' => 'preamble_text',
                                     'parent' => $root->{'contents'}->[-1]
                                   };
    }
  }
  my ($directories, $suffix);
  ($file_name, $directories, $suffix) = fileparse($file_name)
            if ($self->{'TEST'});
  $self = parser() if (!defined($self));
  $self->{'input'} = [{
       'pending' => [[$pending_first_texi_line, {'line_nr' => $line_nr,
                                'macro' => '', 'file_name' => $file_name}]],
       'name' => $file_name,
       'line_nr' => $line_nr,
       'fh' => $filehandle
        }];
  $self->{'info'}->{'input_file_name'} = $file_name;
  $self->{'info'}->{'input_directory'} = $directories;

  my $tree = $self->_parse_texi($root);

  # Find 'text_root', which contains everything before first node/section.
  # if there are elements, 'text_root' is the first content, otherwise it
  # is the root.
  my $text_root;
  if ($tree->{'type'} eq 'text_root') {
    $text_root = $tree;
  } elsif ($tree->{'contents'} and $tree->{'contents'}->[0]
           and $tree->{'contents'}->[0]->{'type'} eq 'text_root') {
    $text_root = $tree->{'contents'}->[0];
  }

  # Put everything before @setfilename in a special type.  This allows to
  # ignore everything before @setfilename.
  if ($self->{'IGNORE_BEFORE_SETFILENAME'} and $text_root and 
      $self->{'extra'} and $self->{'extra'}->{'setfilename'}
      and $self->{'extra'}->{'setfilename'}->{'parent'} eq $text_root) {
    my $before_setfilename = {'type' => 'preamble_before_setfilename',
                              'parent' => $text_root,
                              'contents' => []};
    while ($text_root->{'contents'}->[0] ne $self->{'extra'}->{'setfilename'}) {
      my $content = shift @{$text_root->{'contents'}};
      $content->{'parent'} = $before_setfilename;
      push @{$before_setfilename->{'contents'}}, $content;
    }
    unshift (@{$text_root->{'contents'}}, $before_setfilename)
      if (@{$before_setfilename->{'contents'}});
  }
  #$self->_check_contents_location($tree);

  return $tree;
}

sub parse_texi_line($$;$$$$)
{
  my ($self, $text, $lines_nr, $file, $macro, $fixed_line_number) = @_;

  return undef if (!defined($text));

  if (!ref($text)) {
    $text = _text_to_lines($text);
  }
  #$file =~ s/^.*\/// if (defined($file) and $self->{'TEST'});
  my $lines_array = _complete_line_nr($text, $lines_nr, $file, 
                                     $macro, $fixed_line_number);

  $self = parser() if (!defined($self));
  $self->{'input'} = [{'pending' => $lines_array}];
  my $tree = $self->_parse_texi({'contents' => [], 'type' => 'root_line'});
  return $tree;
}

# return indices informations
sub indices_information($)
{
  my $self = shift;
  return $self->{'index_names'};
}

sub floats_information($)
{
  my $self = shift;
  return $self->{'floats'};
}

sub internal_references_information($)
{
  my $self = shift;
  return $self->{'internal_references'};
}

sub global_commands_information($)
{
  my $self = shift;
  return $self->{'extra'};
}

# @ dircategory_direntry
# perl_encoding
# input_encoding_name
# input_file_name
sub global_informations($)
{
  my $self = shift;
  return $self->{'info'};
}

# Setup labels and nodes info and return labels
sub labels_information
{
  goto &Texinfo::Common::labels_information;
}

# Following are the internal subroutines.  The most important are
# _parse_texi:  the main parser loop.
# _end_line:    called at an end of line.  Handling of @include lines is 
#               done here.
# _next_text:   present the next text fragment, from pending text or line,
#               as described above.

# for debugging
sub _print_current($)
{
  my $current = shift;
  return Texinfo::Common::_print_current($current);
}

# for debugging
sub _print_command_args_texi($)
{
  my $current = shift;
  return '' if (!$current->{'cmdname'});
  my $args = '';
  my $with_brace;
  if ($current->{'args'} and @{$current->{'args'}}) {
    $with_brace 
        = ($current->{'args'}->[0]->{'type'} eq 'brace_command_arg'
           or $current->{'args'}->[0]->{'type'} eq 'brace_command_context');
    $args .= '{' if ($with_brace);
    foreach my $arg (@{$current->{'args'}}) {
      $args .= Texinfo::Convert::Texinfo::convert($arg).', ';
    }
    $args =~ s/, $//;
  }
  chomp($args);
  if ($with_brace) {
    $args .= '}';
  }
  return '@'.$current->{'cmdname'} .$args."\n";
}

sub _print_current_keys($)
{
  my $current = shift;
  my $string = _print_current($current);
  foreach my $key (keys (%$current)) {
    $string .= "   $key: $current->{$key}\n";
  }
  if ($current->{'extra'}) {
    $string .= "    EXTRA\n";
    foreach my $key (keys (%{$current->{'extra'}})) {
      $string .= "    $key: $current->{'extra'}->{$key}\n";
    }
  }
  return $string;
}

# For debugging
sub _print_tree($)
{
  my $tree = shift;

  return Texinfo::Common::print_tree($tree);
}

sub _register_global_command {
  my ($self, $current, $line_nr) = @_;

  my $command = $current->{'cmdname'};

  if ($command eq 'summarycontents' and !$self->{'global_commands'}->{$command}) {
    $command = 'shortcontents';
  }
  if ($self->{'global_commands'}->{$command}) {
    push @{$self->{'extra'}->{$command}}, $current;
    $current->{'line_nr'} = $line_nr if (!$current->{'line_nr'});
    return 1;
  } elsif ($global_unique_commands{$command}) {
    # setfilename ignored in an included file
    $current->{'line_nr'} = $line_nr if (!$current->{'line_nr'});
    if ($command eq 'setfilename'
        and scalar(@{$self->{'input'}}) > 1) {
    } elsif (exists ($self->{'extra'}->{$current->{'cmdname'}})) {
      $self->line_warn(sprintf(__('multiple @%s'), 
                               $current->{'cmdname'}), $line_nr); 
    } else {
      $self->{'extra'}->{$current->{'cmdname'}} = $current;
    }
    return 1;
  }
  return 0;
}

# parse a @macro line
sub _parse_macro_command_line($$$$$;$)
{
  my ($self, $command, $line, $parent, $line_nr) = @_;

  my $macro = { 'cmdname' => $command, 'parent' => $parent, 'contents' => [],
               'extra' => {'arg_line' => $line}, 'line_nr' => $line_nr };
  # REMACRO
  if ($line =~ /^\s+([[:alnum:]][[:alnum:]_-]*)\s*(.*)/) {
    my $macro_name = $1;
    my $args_def = $2;
    my @args;

    if ($args_def =~ s/^\s*{\s*(.*?)\s*}\s*//) {
      @args = split(/\s*,\s*/, $1);
    }
 
    print STDERR "MACRO \@$command $macro_name\n" if ($self->{'DEBUG'});

    $macro->{'args'} = [ 
      { 'type' => 'macro_name', 'text' => $macro_name, 
          'parent' => $macro } ];
    my $index = 0;
    foreach my $formal_arg (@args) {
      push @{$macro->{'args'}}, 
        { 'type' => 'macro_arg', 'text' => $formal_arg, 
          'parent' => $macro};
      if ($formal_arg !~ /^[\w\-]+$/) {
        $self->line_error(sprintf(__("bad or empty \@%s formal argument: %s"),
                                           $command, $formal_arg), $line_nr);
        $macro->{'extra'}->{'invalid_syntax'} = 1;
      }
      $macro->{'extra'}->{'args_index'}->{$formal_arg} = $index;
      $index++;
    }
    # accept an @-command after the arguments in case there is a @c or
    # @comment
    if ($args_def =~ /^\s*[^\@]/) {
      $self->line_error(sprintf(__("bad syntax for \@%s argument: %s"), 
                                 $command, $args_def),
                        $line_nr);
      $macro->{'extra'}->{'invalid_syntax'} = 1;
    }
  } elsif ($line !~ /\S/) {
    $self->line_error(sprintf(
                    __("%c%s requires a name"), ord('@'), $command), $line_nr);
    $macro->{'extra'}->{'invalid_syntax'} = 1;
  } else {
    $self->line_error(sprintf(
                    __("bad name for \@%s"), $command), $line_nr);
    $macro->{'extra'}->{'invalid_syntax'} = 1;
  }
  return $macro;
}

# start a paragraph if in a context where paragraphs are to be started.
sub _begin_paragraph($$;$)
{
  my ($self, $current, $line_nr) = @_;

  # !$current->{'type'} is true for @-commands.  In fact it is unclear
  # that there may be cases of !$current->{'type'} and !$current->{'cmdname'}
  if ((!$current->{'type'} or $type_with_paragraph{$current->{'type'}})
      and !$no_paragraph_contexts{$self->{'context_stack'}->[-1]}) {
    if (!defined($current->{'contents'})) {
      $self->_bug_message("contents undef", $line_nr, $current);
      die;
    }

    # find whether an @indent precedes the paragraph
    my $indent;
    if (scalar(@{$current->{'contents'}})) {
      my $index = scalar(@{$current->{'contents'}}) -1;
      while ($index >= 0
            and !($current->{'contents'}->[$index]->{'type'} 
              and ($current->{'contents'}->[$index]->{'type'} eq 'empty_line'
                   or $current->{'contents'}->[$index]->{'type'} eq 'paragraph'))
            and !($current->{'contents'}->[$index]->{'cmdname'}
                  and $self->{'close_paragraph_commands'}->{$current->{'contents'}->[$index]->{'cmdname'}})) {
        if ($current->{'contents'}->[$index]->{'cmdname'}
          and ($current->{'contents'}->[$index]->{'cmdname'} eq 'indent'
              or $current->{'contents'}->[$index]->{'cmdname'} eq 'noindent')) {
          $indent = $current->{'contents'}->[$index]->{'cmdname'};
          last;
        }
        $index--;
      }
    }
    push @{$current->{'contents'}}, 
            { 'type' => 'paragraph', 'parent' => $current, 'contents' => [] };
    $current->{'contents'}->[-1]->{'extra'}->{$indent} = 1 if ($indent);
    $current = $current->{'contents'}->[-1];
    print STDERR "PARAGRAPH\n" if ($self->{'DEBUG'});
    return $current;
  }
  return 0;
}

sub _begin_preformatted($$)
{
  my ($self, $current) = @_;

  if ($preformatted_contexts{$self->{'context_stack'}->[-1]}) {
    push @{$current->{'contents'}}, 
          { 'type' => $self->{'context_stack'}->[-1], 
            'parent' => $current, 'contents' => [] };
    $current = $current->{'contents'}->[-1];
    print STDERR "PREFORMATTED $self->{'context_stack'}->[-1]\n" if ($self->{'DEBUG'});
  }
  return $current;
}

# wrapper around line_warn.  Set line_nr to be the line_nr of the command,
# corresponding to the opening of the command.  Call line_warn with
# sprintf if needed.
sub _command_warn($$$$;@)
{
  my $self = shift;
  my $current = shift;
  my $line_nr = shift;
  my $message = shift;

  if ($current->{'line_nr'}) {
    $line_nr = $current->{'line_nr'};
  }
  if (@_) {
    $self->line_warn(sprintf($message, @_), $line_nr);
  } else {
    $self->line_warn($message, $line_nr);
  }
}

sub _command_error($$$$;@)
{
  my $self = shift;
  my $current = shift;
  my $line_nr = shift;
  my $message = shift;

  # use the beginning of the @-command for the error message
  # line number if available. 
  # FIXME line_nr currently not registered for regular brace commands
  if ($current->{'line_nr'}) {
    $line_nr = $current->{'line_nr'};
  }
  if (@_) {
    $self->line_error(sprintf($message, @_), $line_nr);
  } else {
    $self->line_error($message, $line_nr);
  }
}

# currently doesn't do much more than
# return $_[1]->{'parent'}
sub _close_brace_command($$$;$$)
{
  my ($self, $current, $line_nr, $closed_command,
      $interrupting_command) = @_;

  if ($current->{'cmdname'} ne 'verb'
      or $current->{'extra'}->{'delimiter'} eq '') {
    if (defined($closed_command)) {
      $self->_command_error($current, $line_nr,
        __("\@end %s seen before \@%s closing brace"), 
                  $closed_command, $current->{'cmdname'});
    } elsif (defined($interrupting_command)) {
      $self->_command_error($current, $line_nr,
        __("\@%s seen before \@%s closing brace"), 
                  $interrupting_command, $current->{'cmdname'});
                                                       
    } else {
      $self->_command_error($current, $line_nr, 
        __("%c%s missing closing brace"), ord('@'), $current->{'cmdname'});
    }
  } else {
    $self->_command_error($current, $line_nr,
       __("\@%s missing closing delimiter sequence: %s}"),
       $current->{'cmdname'}, $current->{'extra'}->{'delimiter'});
  }
  $current = $current->{'parent'};
  return $current;
}

sub _in_code($$)
{
  my ($self, $current) = @_;

  while ($current->{'parent'} and $current->{'parent'}->{'cmdname'}
          and exists $brace_commands{$current->{'parent'}->{'cmdname'}}
          and !exists $context_brace_commands{$current->{'parent'}->{'cmdname'}}) {
    return 1 if ($code_style_commands{$current->{'parent'}->{'cmdname'}});
    $current = $current->{'parent'}->{'parent'};
  }
  return 0;
}

# close brace commands, that don't set a new context (ie @caption, @footnote)
sub _close_all_style_commands($$$;$$)
{
  my ($self, $current, $line_nr, $closed_command,
      $interrupting_command) = @_;

  while ($current->{'parent'} and $current->{'parent'}->{'cmdname'}
          and exists $brace_commands{$current->{'parent'}->{'cmdname'}}
          and !exists $context_brace_commands{$current->{'parent'}->{'cmdname'}}) {
    $current = _close_brace_command($self, $current->{'parent'}, $line_nr,
                                    $closed_command, $interrupting_command);
  }
  return $current;
}

# close brace commands except for @caption, @footnote then the paragraph
sub _end_paragraph($$$;$$)
{
  my ($self, $current, $line_nr, $closed_command,
      $interrupting_command) = @_;

  $current = _close_all_style_commands($self, $current, $line_nr, 
                                       $closed_command, $interrupting_command);
  if ($current->{'type'} and $current->{'type'} eq 'paragraph') {
    print STDERR "CLOSE PARA\n" if ($self->{'DEBUG'});
    $current = $current->{'parent'};
  } 
  return $current;
}

# close brace commands except for @caption, @footnote then the preformatted
sub _end_preformatted($$$;$$)
{
  my ($self, $current, $line_nr, $closed_command,
      $interrupting_command) = @_;

  $current = _close_all_style_commands($self, $current, $line_nr,
                                       $closed_command, $interrupting_command);
  if ($current->{'type'} and $preformatted_contexts{$current->{'type'}}) {
    print STDERR "CLOSE PREFORMATTED $current->{'type'}\n" if ($self->{'DEBUG'});
    # completly remove void preformatted contexts
    if (!@{$current->{'contents'}}) {
      my $removed = pop @{$current->{'parent'}->{'contents'}};
      print STDERR "popping $removed->{'type'}\n" if ($self->{'DEBUG'});
    }
    $current = $current->{'parent'};
  }
  return $current;
}

# check that there are no text holding environment (currently
# checking only paragraphs and preformatted) in contents
sub _check_no_text($)
{
  my $current = shift;
  my $after_paragraph = 0;
  foreach my $content (@{$current->{'contents'}}) {
    if ($content->{'type'} and $content->{'type'} eq 'paragraph') {
      $after_paragraph = 1;
      last;
    } elsif ($content->{'type'} and $preformatted_contexts{$content->{'type'}}) {
      foreach my $preformatted_content (@{$content->{'contents'}}) {
        if ((defined($preformatted_content->{'text'}) 
             and $preformatted_content->{'text'} =~ /\S/)
            or ($preformatted_content->{'cmdname'} 
                and ($preformatted_content->{'cmdname'} ne 'c'
                     and $preformatted_content->{'cmdname'} ne 'comment')
                and !($preformatted_content->{'type'} 
                      and $preformatted_content->{'type'} eq 'index_entry_command'))) {
          $after_paragraph = 1;
          last;
        }
      }
      last if ($after_paragraph);
    }
  }
  return $after_paragraph;
}

# put everything after the last @item/@itemx in an item_table type container
# and distinguish table_term and table_entry.
sub _gather_previous_item($$;$$)
{
  my ($self, $current, $next_command, $line_nr) = @_;

  # nothing to do in that case.
  if ($current->{'contents'}->[-1]->{'type'}
      and $current->{'contents'}->[-1]->{'type'} eq 'before_item') {
    if ($next_command and $next_command eq 'itemx') {
      $self->line_warn(sprintf(__("\@itemx should not begin \@%s"), 
                                $current->{'cmdname'}), $line_nr);
    }
    return;
  }
  my $type;
  # if before an itemx, the type is different since there should not be 
  # real content, so it may be treated differently
  if ($next_command and $next_command eq 'itemx') {
    $type = 'inter_item';
  } else {
    $type = 'table_item';
  }
  my $table_gathered = {'type' => $type,
                       'contents' => []};
  # remove everything that is not an @item/@items or before_item to 
  # put it in the table_item, starting from the end.
  my $contents_count = scalar(@{$current->{'contents'}});
  for (my $i = 0; $i < $contents_count; $i++) {
    if ($current->{'contents'}->[-1]->{'cmdname'} 
        and ($current->{'contents'}->[-1]->{'cmdname'} eq 'item' 
             or ($current->{'contents'}->[-1]->{'cmdname'} eq 'itemx'))) {
      last;
    } else {
      my $item_content = pop @{$current->{'contents'}};
      $item_content->{'parent'} = $table_gathered;
      unshift @{$table_gathered->{'contents'}}, $item_content;
    }
  }
  if ($type eq 'table_item') {
    my $table_entry = {'type' => 'table_entry',
                    'parent' => $current,
                    'contents' => []};
    my $table_term = {'type' => 'table_term',
                    'parent' => $table_entry,
                    'contents' => []};
    push @{$table_entry->{'contents'}}, $table_term;
    my $contents_count = scalar(@{$current->{'contents'}});
    for (my $i = 0; $i < $contents_count; $i++) {
      if ($current->{'contents'}->[-1]->{'type'} 
           and ($current->{'contents'}->[-1]->{'type'} eq 'before_item'
                or $current->{'contents'}->[-1]->{'type'} eq 'table_entry')) {
        last;
      } else {
        my $item_content = pop @{$current->{'contents'}};
        $item_content->{'parent'} = $table_term;
        unshift @{$table_term->{'contents'}}, $item_content;
        # debug
        if (! (($item_content->{'cmdname'} 
                and ($item_content->{'cmdname'} eq 'itemx'
                    or $item_content->{'cmdname'} eq 'item'))
               or ($item_content->{'type'} 
                   and $item_content->{'type'} eq 'inter_item'))) {
          $self->_bug_message("wrong element in table term", $line_nr, 
                              $item_content);
        }
      }
    }
    push @{$current->{'contents'}}, $table_entry;
    if (scalar(@{$table_gathered->{'contents'}})) {
      push @{$table_entry->{'contents'}}, $table_gathered;
      $table_gathered->{'parent'} = $table_entry;
    }
  } else {
    my $after_paragraph = _check_no_text($table_gathered);
    if ($after_paragraph) {
      $self->line_error(__("\@itemx must follow \@item"), $line_nr);
    }
    if (scalar(@{$table_gathered->{'contents'}})) {
      push @{$current->{'contents'}}, $table_gathered;
      $table_gathered->{'parent'} = $current;
    }
  }
}

# Starting from the end, gather everything util the def_line to put in 
# a def_item
sub _gather_def_item($;$)
{
  my ($current, $next_command) = @_;

  my $type;
  # means that we are between a @def*x and a @def
  if ($next_command) {
    $type = 'inter_def_item';
  } else {
    $type = 'def_item';
  }

  # This may happen for a construct like
  # @deffnx a b @section
  # but otherwise the end of line will lead to the command closing
  return if (!$current->{'cmdname'} or $current->{'cmdname'} =~ /x$/);
  my $def_item = {'type' => $type,
                  'parent' => $current,
                  'contents' => []};
  # remove everything that is not a def_line to put it in the def_item,
  # starting from the end.
  my $contents_count = scalar(@{$current->{'contents'}});
  for (my $i = 0; $i < $contents_count; $i++) {
    if ($current->{'contents'}->[-1]->{'type'} 
        and $current->{'contents'}->[-1]->{'type'} eq 'def_line') {
     #   and !$current->{'contents'}->[-1]->{'extra'}->{'not_after_command'}) {
      last;
    } else {
      my $item_content = pop @{$current->{'contents'}};
      $item_content->{'parent'} = $def_item;
      unshift @{$def_item->{'contents'}}, $item_content;
    }
  }
  if (scalar(@{$def_item->{'contents'}})) {
    push @{$current->{'contents'}}, $def_item;
  }
}

# close formats
sub _close_command_cleanup($$) {
  my ($self, $current) = @_;

  return unless ($current->{'cmdname'});
  # remove the dynamic counters in multitable, they are not of use in the final
  # tree.  Also determine the multitable_body and multitable_head with 
  # @item or @headitem rows.
  if ($current->{'cmdname'} eq 'multitable') {
    my $in_head_or_rows;
    my @contents = @{$current->{'contents'}};
    $current->{'contents'} = [];
    foreach my $row (@contents) {
      if ($row->{'type'} and $row->{'type'} eq 'row') {
        delete $row->{'cells_count'};
        if ($row->{'contents'}->[0]->{'cmdname'} eq 'headitem') {
          if (!$in_head_or_rows) {
            push @{$current->{'contents'}}, {'type' => 'multitable_head',
                                             'parent' => $current};
            $in_head_or_rows = 1;
          }
        } elsif ($row->{'contents'}->[0]->{'cmdname'} eq 'item') {
          if (!defined($in_head_or_rows) or $in_head_or_rows) {
            push @{$current->{'contents'}}, {'type' => 'multitable_body',
                                             'parent' => $current};
            $in_head_or_rows = 0;
          }
        }
        push @{$current->{'contents'}->[-1]->{'contents'}}, $row;
        $row->{'parent'} = $current->{'contents'}->[-1];
      } else {
        push @{$current->{'contents'}}, $row;
        $in_head_or_rows = undef;
      }
    }
    delete $current->{'rows_count'};
  } elsif ($item_container_commands{$current->{'cmdname'}}) {
    delete $current->{'items_count'};
  }

  # put everything after the last @def*x command in a def_item type container.
  if ($def_commands{$current->{'cmdname'}}) {
    # At this point the end command hasn't been added to the command contents.
    # so checks cannot be done at this point.
    _gather_def_item($current);
  }

  if ($item_line_commands{$current->{'cmdname'}}) {
    # At this point the end command hasn't been added to the command contents.
    # so checks cannot be done at this point.
    if (@{$current->{'contents'}}) {
      _gather_previous_item($self, $current);
    }
  }
  
  # put end out of before_item, and replace it at the end of the parent.
  # remove empty before_item.
  # warn if not empty before_item, but format is empty
  if ($block_item_commands{$current->{'cmdname'}}) {
    if (@{$current->{'contents'}}) {
      my $leading_spaces = 0;
      my $before_item;
      if ($current->{'contents'}->[0]->{'type'}
          and $current->{'contents'}->[0]->{'type'} eq 'empty_line_after_command'
          and $current->{'contents'}->[1]
          and $current->{'contents'}->[1]->{'type'}
          and $current->{'contents'}->[1]->{'type'} eq 'before_item') {
        $leading_spaces = 1;
        $before_item = $current->{'contents'}->[1];
      } elsif ($current->{'contents'}->[0]->{'type'} 
              and $current->{'contents'}->[0]->{'type'} eq 'before_item') {
        $before_item = $current->{'contents'}->[0];
      }
      if ($before_item) {
        if ($current->{'extra'}->{'end_command'}
            and @{$before_item->{'contents'}} 
            and $before_item->{'contents'}->[-1] eq $current->{'extra'}->{'end_command'}) {
          my $end = pop @{$before_item->{'contents'}};
          $end->{'parent'} = $current;
          push @{$current->{'contents'}}, $end;
        }
        # remove empty before_items
        if (!@{$before_item->{'contents'}}) {
          if ($leading_spaces) {
            my $space = shift @{$current->{'contents'}};
            shift @{$current->{'contents'}};
            unshift @{$current->{'contents'}}, $space;
          } else {
            shift @{$current->{'contents'}};
          }
        } else {
          # warn if not empty before_item, but format is empty
          my $empty_before_item = 1;
          foreach my $before_item_content (@{$before_item->{'contents'}}) {
            if (!$before_item_content->{'cmdname'} or 
                  ($before_item_content->{'cmdname'} ne 'c' 
                   and $before_item_content->{'cmdname'} ne 'comment')) {
              $empty_before_item = 0;
              last;
            }
          }
          if (!$empty_before_item) {
            my $empty_format = 1;
            foreach my $format_content (@{$current->{'contents'}}) {
              next if ($format_content eq $before_item);
              if (($format_content->{'cmdname'} and 
                   ($format_content->{'cmdname'} ne 'c'
                    and $format_content->{'cmdname'} ne 'comment'
                    and $format_content->{'cmdname'} ne 'end'))
                  or ($format_content->{'type'} and
                    ($format_content->{'type'} ne 'empty_line_after_command'))) {
                $empty_format = 0;
                last;
              }
            }
            if ($empty_format) {
              $self->line_warn(sprintf(__("\@%s has text but no \@item"),
                                        $current->{'cmdname'}), $current->{'line_nr'});                       
            }
          }
        }
      }
    }
  }
}

# close the current command, with error messages and give the parent.
# If the last argument is given it is the command being closed if
# hadn't there be an error, currently only block command, used for a
# better error message.
sub _close_current($$$;$$)
{
  my ($self, $current, $line_nr, $closed_command,
      $interrupting_command) = @_;

  if ($current->{'cmdname'}) {
    print STDERR "CLOSING(_close_current) \@$current->{'cmdname'}\n" if ($self->{'DEBUG'});
    if (exists($brace_commands{$current->{'cmdname'}})) {
      pop @{$self->{'context_stack'}}
         if (exists $context_brace_commands{$current->{'cmdname'}});
      $current = _close_brace_command($self, $current, $line_nr, 
                                      $closed_command, $interrupting_command);
    } elsif (exists($block_commands{$current->{'cmdname'}})) {
      if (defined($closed_command)) {
        $self->line_error(sprintf(__("`\@end' expected `%s', but saw `%s'"),
                                   $current->{'cmdname'}, $closed_command), $line_nr);
      } elsif ($interrupting_command) {
        $self->line_error(sprintf(__("\@%s seen before \@end %s"),
                                  $interrupting_command, $current->{'cmdname'}),
                          $line_nr);
      } else {
        $self->line_error(sprintf(__("no matching `%cend %s'"),
                                   ord('@'), $current->{'cmdname'}), $line_nr);
        if ($block_commands{$current->{'cmdname'}} eq 'conditional') {
          # in this case we are within an ignored conditional
          my $conditional = pop @{$current->{'parent'}->{'contents'}};
        }
      }
      if ($preformatted_commands{$current->{'cmdname'}}
          or $menu_commands{$current->{'cmdname'}}
          or $format_raw_commands{$current->{'cmdname'}}) {
        my $context = pop @{$self->{'context_stack'}};
      }
      pop @{$self->{'regions_stack'}} 
         if ($region_commands{$current->{'cmdname'}});
      $current = $current->{'parent'};
    } else {
      # There @item and @tab commands are closed, and also line commands
      # with invalid content
      $current = $current->{'parent'};
    }
  } elsif ($current->{'type'}) {
    print STDERR "CLOSING type $current->{'type'}\n" if ($self->{'DEBUG'});
    if ($current->{'type'} eq 'bracketed') {
      $self->_command_error($current, $line_nr, 
                            __("misplaced %c"), ord('{'));
      if ($current->{'contents'}
          and @{$current->{'contents'}}
          and $current->{'contents'}->[0]->{'type'}
          and $current->{'contents'}->[0]->{'type'}
                eq 'empty_spaces_before_argument') {
        # remove spaces element from tree and update extra values
        _abort_empty_line($self, $current)
      }

    } elsif ($current->{'type'} eq 'menu_comment' 
          or $current->{'type'} eq 'menu_entry_description') {
      my $context = pop @{$self->{'context_stack'}};
      if ($context ne 'preformatted') {
        $self->_bug_message("context $context instead of preformatted", 
                            $line_nr, $current);
      }
      # close empty menu_comment
      if (!@{$current->{'contents'}}) {
        pop @{$current->{'parent'}->{'contents'}};
      }
    } elsif ($current->{'type'} eq 'line_arg'
             or $current->{'type'} eq 'block_line_arg') {
      my $context = pop @{$self->{'context_stack'}};
      if ($context ne 'line' and $context ne 'def') {
        $self->_bug_message("context $context instead of line or def", 
                            $line_nr, $current);
        die;
      }
    }
    $current = $current->{'parent'};
  } else { # Should never go here.
    $current = $current->{'parent'} if ($current->{'parent'});
    $self->_bug_message("No type nor cmdname when closing", 
                        $line_nr, $current);
  }
  return $current;
}

# a closed_command arg means closing until that command is found.
# no command arg means closing until the root or a root_command
# is found.
sub _close_commands($$$;$$)
{
  my ($self, $current, $line_nr, $closed_command,
      $interrupting_command) = @_;

  $current = _end_paragraph($self, $current, $line_nr, $closed_command, 
                            $interrupting_command);
  $current = _end_preformatted($self, $current, $line_nr, $closed_command,
                               $interrupting_command);

        # stop if the command is found
  while (!($closed_command and $current->{'cmdname'}
           and $current->{'cmdname'} eq $closed_command) 
         # stop if at the root
         and $current->{'parent'}
     # stop if in a root command 
     # or in a context_brace_commands and searching for a specific 
     # end block command (with $closed_command set).  
     # This second condition means that a footnote is not closed when 
     # looking for the end of a block command, but is closed when 
     # completly closing the stack.
         and !($current->{'cmdname'}
               and ($root_commands{$current->{'cmdname'}}
                    or ($closed_command and $current->{'parent'}->{'cmdname'}
                       and $context_brace_commands{$current->{'parent'}->{'cmdname'}})))){
    _close_command_cleanup($self, $current);
    $current = _close_current($self, $current, $line_nr, $closed_command, 
                              $interrupting_command);
  }

  my $closed_element;
  if ($closed_command and $current->{'cmdname'} 
      and $current->{'cmdname'} eq $closed_command) {
    if ($preformatted_commands{$current->{'cmdname'}}) {
      my $context = pop @{$self->{'context_stack'}};
      if ($context ne 'preformatted') {
        $self->_bug_message("context $context instead of preformatted for $closed_command", 
                            $line_nr, $current);
      }
    } elsif ($format_raw_commands{$current->{'cmdname'}}) {
      my $context = pop @{$self->{'context_stack'}};
      if ($context ne 'rawpreformatted') {
        $self->_bug_message("context $context instead of rawpreformatted for $closed_command", 
                            $line_nr, $current);
      }
    } elsif ($menu_commands{$current->{'cmdname'}}) {
      my $context = pop @{$self->{'context_stack'}};
      # may be in menu, but context is preformatted if in a preformatted too.
      if ($context ne 'menu' and $context ne 'preformatted') {
        $self->_bug_message("context $context instead of preformatted or menu for $closed_command", 
                            $line_nr, $current);
      }
    }
    pop @{$self->{'regions_stack'}} 
       if ($region_commands{$current->{'cmdname'}});
    $closed_element = $current;
    #$self->_close_command_cleanup($current);
    $current = $current->{'parent'};
  } elsif ($closed_command) {
    $self->line_error(sprintf(__("unmatched `%c%s'"), 
                       ord('@'), "end $closed_command"), $line_nr);
  }
  return ($closed_element, $current);
}

# begin paragraph if needed.  If not try to merge with the previous
# content if it is also some text.
# NOTE - this sub has an XS override
sub _merge_text {
  my ($self, $current, $text) = @_;

  my $paragraph;

  my $no_merge_with_following_text = 0;
  if ($text =~ /\S/) {
    my $leading_spaces;
    if ($text =~ /^(\s+)/) {
      $leading_spaces = $1;
    }
    if ($current->{'contents'} and @{$current->{'contents'}}
      and $current->{'contents'}->[-1]->{'type'}
      and ($current->{'contents'}->[-1]->{'type'} eq 'empty_line_after_command'
         or $current->{'contents'}->[-1]->{'type'} eq 'empty_spaces_after_command'
         or $current->{'contents'}->[-1]->{'type'} eq 'empty_spaces_before_argument'
         or $current->{'contents'}->[-1]->{'type'} eq 'empty_spaces_after_close_brace')) {
      $no_merge_with_following_text = 1;
    }
    if (_abort_empty_line($self, $current, $leading_spaces)) {
      $text =~ s/^(\s+)//;
    } 

    $paragraph = _begin_paragraph($self, $current);
    $current = $paragraph if ($paragraph);
  }

  if (!defined($current->{'contents'})) {
    $self->_bug_message("No contents in _merge_text", 
                            undef, $current);
    die;
  }

  if (!$no_merge_with_following_text
      and @{$current->{'contents'}} 
      and exists($current->{'contents'}->[-1]->{'text'}) 
      and $current->{'contents'}->[-1]->{'text'} !~ /\n/) {
    $current->{'contents'}->[-1]->{'text'} .= $text;
    print STDERR "MERGED TEXT: $text|||\n" if ($self->{'DEBUG'});
  } else {
    push @{$current->{'contents'}}, { 'text' => $text, 'parent' => $current };
    print STDERR "NEW TEXT: $text|||\n" if ($self->{'DEBUG'});
  }
  return $current;
}

# return the parent if in a item_container command, itemize or enumerate
sub _item_container_parent($)
{
  my $current = shift;
  if ((($current->{'cmdname'} and $current->{'cmdname'} eq 'item')
       or ($current->{'type'} and $current->{'type'} eq 'before_item'))
      and ($current->{'parent'} and $current->{'parent'}->{'cmdname'}
        and $item_container_commands{$current->{'parent'}->{'cmdname'}})) {
    return ($current->{'parent'});
  }
  return undef;
}

# return the parent if in a item_line command, @*table
sub _item_line_parent($)
{
  my $current = shift;
  if ($current->{'type'} and $current->{'type'} eq 'before_item'
            and $current->{'parent'}) {
    $current = $current->{'parent'};
  }
  return $current if ($current->{'cmdname'} 
                       and $item_line_commands{$current->{'cmdname'}});
  return undef;
}

# return the parent if in a multitable
sub _item_multitable_parent($)
{
  my $current = shift;
  if (($current->{'cmdname'} and ($current->{'cmdname'} eq 'headitem'
       or $current->{'cmdname'} eq 'item' or $current->{'cmdname'} eq 'tab'))
      and $current->{'parent'} and $current->{'parent'}->{'parent'}) {
    $current = $current->{'parent'}->{'parent'};
  } elsif ($current->{'type'} and $current->{'type'} eq 'before_item'
            and $current->{'parent'}) {
    $current = $current->{'parent'};
  }
  return $current if ($current->{'cmdname'} 
                       and $current->{'cmdname'} eq 'multitable');
  return undef;
}

sub _save_line_directive
{
  my ($self, $line_nr, $file_name) = @_;

  my $input = $self->{'input'}->[0];
  return if !$input;
  $input->{'line_nr'} = $line_nr if $line_nr;
  $input->{'name'} = $file_name if $file_name;
}

# returns next text fragment, be it pending from a macro expansion or 
# text or file
sub _next_text($$)
{
  my ($self, $line_nr) = @_;
 
  while (@{$self->{'input'}}) {
    my $input = $self->{'input'}->[0];
    if (@{$input->{'pending'}}) {
      my $new_text = shift @{$input->{'pending'}};
      if ($new_text->[1] and $new_text->[1]->{'end_macro'}) {
        delete $new_text->[1]->{'end_macro'};
        my $top_macro = shift @{$self->{'macro_stack'}};
        print STDERR "SHIFT MACRO_STACK(@{$self->{'macro_stack'}}): $top_macro->{'args'}->[0]->{'text'}\n"
          if ($self->{'DEBUG'});
      }
      return ($new_text->[0], $new_text->[1]);
    } elsif ($input->{'fh'}) {
      my $fh = $input->{'fh'};
      my $line = <$fh>;
      if (defined($line)) {
        # add an end of line if there is none at the end of file
        if (eof($fh) and $line !~ /\n/) {
          $line .= "\n";
        }
        $line =~ s/\x{7F}.*\s*//;
        $input->{'line_nr'}++;
        return ($line, {'line_nr' => $input->{'line_nr'}, 
            'file_name' => $input->{'name'},
            'macro' => ''});
      }
    }
    my $previous_input = shift(@{$self->{'input'}});
    # Don't close STDIN
    if ($previous_input->{'fh'} and $previous_input->{'name'} ne '-') {
      if (!close($previous_input->{'fh'})) {
        $self->document_warn(sprintf(__("error on closing %s: %s"),
                                     $previous_input->{'name'}, $!));

      }
    }
  }

  return (undef, $line_nr);
}

# collect text and line numbers until an end of line is found.
sub _new_line($$)
{
  my ($self, $line_nr) = @_;

  my $new_line = '';

  while (1) {
    my $new_text;
    ($new_text, $line_nr) = _next_text($self, $line_nr);
    if (!defined($new_text)) {
      $new_line = undef if ($new_line eq '');
      last;
    }

    $new_line .= $new_text;

    my $chomped_text = $new_text;
    last if chomp($chomped_text);
  }
  return ($new_line, $line_nr);
}

# $MACRO is the element in the tree defining the macro.
sub _expand_macro_arguments($$$$)
{
  my ($self, $macro, $line, $line_nr) = @_;

  my $braces_level = 1;
  my $arguments = [ '' ];
  my $arg_nr = 0;
  my $args_total = scalar(@{$macro->{'args'}}) -1;
  my $name = $macro->{'args'}->[0]->{'text'};

  my $line_nr_orig = $line_nr;

  while (1) {
    if ($line =~ s/([^\\{},]*)([\\{},])//) {
      my $separator = $2;
      $arguments->[-1] .= $1;
      if ($separator eq '\\') {
        if ($line =~ s/^(.)//) {
          my $protected_char = $1;
          if ($protected_char !~ /[\\{},]/) {
            $arguments->[-1] .= '\\';
          }
          $arguments->[-1] .= $protected_char;
          
          print STDERR "MACRO ARG: $separator: $protected_char\n" if ($self->{'DEBUG'});
        } else {
          $arguments->[-1] .= '\\';
          print STDERR "MACRO ARG: $separator\n" if ($self->{'DEBUG'});
        }
      } elsif ($separator eq ',') {
        if ($braces_level == 1) {
          if (scalar(@$arguments) < $args_total) {
            push @$arguments, '';
            $line =~ s/^\s*//;
            print STDERR "MACRO NEW ARG\n" if ($self->{'DEBUG'});
          } else {
            # implicit quoting when there is one argument.
            if ($args_total != 1) {
              $self->line_error(sprintf(__(
                                     "macro `%s' called with too many args"), 
                                        $name), $line_nr);
            }
            $arguments->[-1] .= ',';
          }
        } else {
          $arguments->[-1] .= ',';
        }
      } elsif ($separator eq '}') {
        $braces_level--;
        last if ($braces_level == 0);
        $arguments->[-1] .= $separator;
      } elsif ($separator eq '{') {
        $braces_level++;
        $arguments->[-1] .= $separator;
      }
    } else {
      print STDERR "MACRO ARG end of line\n" if ($self->{'DEBUG'});
      $arguments->[-1] .= $line;

      ($line, $line_nr) = _new_line($self, $line_nr);
      if (!defined($line)) {
        $self->line_error(sprintf(__("\@%s missing closing brace"), 
           $name), $line_nr_orig);
        return ($arguments, "\n", $line_nr);
      }
    }
  }
  if ($args_total == 0 and $arguments->[0] ne '') {
    $self->line_error(sprintf(__(
               "macro `%s' declared without argument called with an argument"), 
                                $name), $line_nr);
  }
  print STDERR "END MACRO ARGS EXPANSION(".scalar(@$arguments)."): ".
                  join("|\n", @$arguments) ."|\n" if ($self->{'DEBUG'});
  return ($arguments, $line, $line_nr);
}

# $MACRO is a member of $self->{'macros'}.
sub _expand_macro_body($$$$) {
  my ($self, $macro, $args, $line_nr) = @_;

  my $macrobody = $macro->{'macrobody'};
  my $args_total = scalar(@{$macro->{'element'}->{'args'}}) -1;
  my $args_index = $macro->{'args_index'};

  my $i;
  for ($i=0; $i<=$args_total; $i++) {
    $args->[$i] = "" unless (defined($args->[$i]));
  }

  my $result = '';
  while ($macrobody ne '') {
    if ($macrobody =~ s/^([^\\]*)\\//o) {
      $result .= $1;
      if ($macrobody =~ s/^\\//) {
        $result .= '\\';
      } elsif ($macrobody =~ s/^([^\\]*)\\//) {
        my $arg = $1;
        if (defined($args_index->{$arg})) {
          $result .= $args->[$args_index->{$arg}];
        } else {
          $self->line_error(sprintf(__(
         "\\ in \@%s expansion followed `%s' instead of parameter name or \\"), 
             $macro->{'element'}->{'args'}->[0]->{'text'}, $arg), $line_nr);
          $result .= '\\' . $arg;
        }
      }
      next;
    }
    $result .= $macrobody;
    last;
  }
  return $result;
}

# each time a new line appeared, a container is opened to hold the text
# consisting only of spaces.  This container is removed here, typically
# this is called when non-space happens on a line.
# NOTE - this sub has an XS override
sub _abort_empty_line {
  my ($self, $current, $additional_spaces) = @_;

  $additional_spaces = '' if (!defined($additional_spaces));
  if ($current->{'contents'} and @{$current->{'contents'}} 
       and $current->{'contents'}->[-1]->{'type'}
       and ($current->{'contents'}->[-1]->{'type'} eq 'empty_line' 
           or $current->{'contents'}->[-1]->{'type'} eq 'empty_line_after_command'
           or $current->{'contents'}->[-1]->{'type'} eq 'empty_spaces_before_argument'
           or $current->{'contents'}->[-1]->{'type'} eq 'empty_spaces_after_close_brace')) {

    my $spaces_element = $current->{'contents'}->[-1];

    my $owning_element;
    if ($spaces_element->{'extra'}
        and $spaces_element->{'extra'}->{'command'}) {
      $owning_element = $spaces_element->{'extra'}->{'command'};
    }

    print STDERR "ABORT EMPTY "
      .$spaces_element->{'type'}
      ." additional text |$additional_spaces|,"
      ." current |$spaces_element->{'text'}|\n"
        if ($self->{'DEBUG'});

    $spaces_element->{'text'} .= $additional_spaces;
    # remove empty 'empty*before'.
    if ($spaces_element->{'text'} eq '') {
      pop @{$current->{'contents'}};

    } elsif ($spaces_element->{'type'} eq 'empty_line') {
      # exactly the same condition as to begin a paragraph
      if ((!$current->{'type'} or $type_with_paragraph{$current->{'type'}})
         and !$no_paragraph_contexts{$self->{'context_stack'}->[-1]}) {
        $spaces_element->{'type'} = 'empty_spaces_before_paragraph';
      } else { 
        delete $spaces_element->{'type'};
      }
    } elsif ($spaces_element->{'type'} eq 'empty_line_after_command'
             or $spaces_element->{'type'} eq 'empty_spaces_before_argument') {
      if ($owning_element) {
        # Remove element from main tree. It will still be referenced in
        # the 'extra' hash as 'spaces_before_argument'.
        pop @{$current->{'contents'}};

        $owning_element->{'extra'}->{'spaces_before_argument'}
          = $spaces_element->{'text'};
      } else {
        $spaces_element->{'type'} = 'empty_spaces_after_command';
      }
    }

    return 1;
  }
  return 0;
}

# isolate last space in a command to help expansion disregard unuseful spaces.
sub _isolate_last_space
{
  my ($self, $current) = @_;

  return if (!$current->{'contents'} or !@{$current->{'contents'}});

  # Store a final comment command in the 'extra' hash.
  if (scalar(@{$current->{'contents'}}) >= 1 
      and $current->{'contents'}->[-1]->{'cmdname'}
      and ($current->{'contents'}->[-1]->{'cmdname'} eq 'c'
            or $current->{'contents'}->[-1]->{'cmdname'} eq 'comment')) {
     $current->{'extra'}->{'comment_at_end'} = pop @{$current->{'contents'}}; 
     # TODO: @c should probably not be allowed inside most brace commands
     # as this would be difficult to implement properly in TeX.
  }

  return if !@{$current->{'contents'}}
            or !defined($current->{'contents'}->[-1]->{'text'}) 
            or ($current->{'contents'}->[-1]->{'type'}
                  and (!$current->{'type'}
                        or $current->{'type'} ne 'line_arg'))
            or $current->{'contents'}->[-1]->{'text'} !~ /\s+$/;

  if ($current->{'type'} and $current->{'type'} eq 'menu_entry_node') {
    if ($current->{'contents'}->[-1]->{'text'} !~ /\S/) {
      $current->{'contents'}->[-1]->{'type'} = 'space_at_end_menu_node';
    } else {
      $current->{'contents'}->[-1]->{'text'} =~ s/(\s+)$//;
      my $new_spaces = { 'text' => $1, 'parent' => $current,
        'type' => 'space_at_end_menu_node' };
      push @{$current->{'contents'}}, $new_spaces;
    }
  } else {
    # Store final spaces in 'spaces_after_argument'.
    if ($current->{'contents'}->[-1]->{'text'} !~ /\S/) {
      my $end_spaces = $current->{'contents'}->[-1]->{'text'};
      pop @{$current->{'contents'}};
      $current->{'extra'}->{'spaces_after_argument'} = $end_spaces;
    } else {
      $current->{'contents'}->[-1]->{'text'} =~ s/(\s+)$//;
      $current->{'extra'}->{'spaces_after_argument'} = $1;
    }
  }
}

# $NODE->{'contents'} is the Texinfo for the specification of a node.
# Returned object is a hash with two fields:
#
#     manual_content - Texinfo tree for a manual name extracted from the
#                      node specification.
#     node_content - Texinfo tree for the node name on its own
#
# retrieve a leading manual name in parentheses, if there is one.
sub _parse_node_manual($)
{
  my $node = shift;
  return Texinfo::Common::parse_node_manual ($node);
}

sub _parse_float_type($)
{
  my $current = shift;
  if ($current->{'args'} and @{$current->{'args'}}) {
    if (@{$current->{'args'}->[0]->{'contents'}}) {
      my $normalized 
        = Texinfo::Convert::Texinfo::convert(
          {'contents' => $current->{'args'}->[0]->{'contents'}});
      $current->{'extra'}->{'type'}->{'content'} =
                                      $current->{'args'}->[0]->{'contents'};
      $current->{'extra'}->{'type'}->{'normalized'} = $normalized;
      return 1;
    }
  }
  $current->{'extra'}->{'type'}->{'normalized'} = '';
  return 0;
}

# split non-space text elements into strings without [ ] ( ) , and single
# character strings with one of them
sub _split_delimiters
{
  my ($self, $root) = @_;

  if (defined $root->{'type'} # 'spaces' for spaces
      or !defined $root->{'text'}) {
    return $root;
  } else {
    my @elements;
    my $type;
    my $chars = quotemeta '[](),';
    my $text = $root->{'text'};
    while (1) {
      if ($text =~ s/^([^$chars]+)//) {
        push @elements, {'text' => $1, 'parent' => $root->{'parent'}};
      } elsif ($text =~ s/^([$chars])//) {
        push @elements, {'text' => $1, 'type' => 'delimiter',
                         'parent' => $root->{'parent'}};
      } else {
        last;
      }
    }
    return @elements;
  }
}

# split text elements into whitespace and non-whitespace
sub _split_def_args
{
  my ($self, $root) = @_;

  if ($root->{'type'} and $root->{'type'} eq 'spaces_inserted') {
    return $root;
  } elsif (defined $root->{'text'}) {
    my @elements;
    my $type;
    my @split_text = split /(?<=\s)(?=\S)|(?<=\S)(?=\s)/, $root->{'text'};
    if ($split_text[0] =~ /^\s*$/) {
      $type = 'spaces';
    }
    for my $t (@split_text) {
      my $e = {'text' => $t };
      if ($type) {
        $e->{'type'} = $type;
        $type = undef;
      } else {
        $type = 'spaces';
      }
      $e->{'parent'} = $root->{'parent'};
      push @elements, $e;
    }
    return @elements;
  } elsif ($root->{'type'} and $root->{'type'} eq 'bracketed') {
    _isolate_last_space($self, $root);
    $root->{'type'} = 'bracketed_def_content';
  }
  return $root;
}

# definition line parsing
sub _parse_def($$$)
{
  my ($self, $command, $current) = @_;

  my $contents = $current->{'contents'};
  my $empty_spaces_after_command;
  
  my @new_contents;
  my @contents = @$contents;
  if ($contents[0] and $contents[0]->{'type'}
        and ($contents[0]->{'type'} eq 'empty_spaces_after_command'
          or $contents[0]->{'type'} eq 'empty_line_after_command')) {
    $empty_spaces_after_command = shift @contents;
  }

  if ($def_aliases{$command}) {
    my $real_command = $def_aliases{$command};
    my $prepended = $def_map{$command}->{$real_command};


    my $bracketed = { 'type' => 'bracketed_inserted',
                      'parent' => $current };
    my $content = { 'text' => $prepended, 'parent' => $bracketed };
    if ($self->{'documentlanguage'}) {
      $content->{'type'} = 'untranslated';
      $content->{'extra'}->{'documentlanguage'} = $self->{'documentlanguage'};
    }
    @{$bracketed->{'contents'}} = ($content);

    unshift @contents, $bracketed,
                       { 'text' => ' ', 'type' => 'spaces_inserted',
                         'parent' => $current,
                       };

    $command = $def_aliases{$command};
  }
  @contents = map (_split_def_args($self, $_), @contents );
  @new_contents = @contents;

  $current->{'contents'} = \@new_contents;

  my @result;
  my @args = @{$def_map{$command}};
  my $arg_type;

  $arg_type = pop @args if ($args[-1] eq 'arg' or $args[-1] eq 'argtype');
  # If $arg_type is not set (for @def* commands that are not documented
  # to take args), everything happens as if arg_type was set to 'arg'.

  #  Fill in everything up to the args, collecting adjacent non-whitespace 
  #  elements into a single element, e.g 'a@i{b}c'.
  my $argument_content = [];
  my $arg = shift (@args);

  my $i = 0; # the offset in @new_contents of $token
  while (@contents) {
    my $token = $contents[0];
    # finish previous item
    if ( $token->{'type'}
        and ($token->{'type'} eq 'spaces'
               or $token->{'type'} eq 'spaces_inserted'
               or $token->{'type'} eq 'bracketed_def_content'
               or $token->{'type'} eq 'bracketed_inserted'
               or $token->{'type'} eq 'delimiter')) {
      # we create a {'contents' =>} only if there is more than one
      # content gathered.
      if (scalar(@$argument_content)) {
        if (scalar(@$argument_content) > 1) {
          my $e = {'contents' => $argument_content,
                   'type' => 'def_aggregate',
                   'parent' => $current };
          push @result, [$arg, $e];
          # Replace in the main tree.
          splice @new_contents,
                 $i - scalar(@$argument_content),
                 scalar(@$argument_content),
                 $e;
          for my $e2 (@$argument_content) {
            $e2->{'parent'} = $e;
          }
          $i -= scalar(@$argument_content) - 1;
        } elsif (scalar(@$argument_content) == 1) {
          push @result, [$arg, $argument_content->[0]];
        }
        $argument_content = [];
        if ($token->{'type'} eq 'spaces'
            or $token->{'type'} eq 'spaces_inserted') {
          $arg = shift (@args);
        }
      }
    }

    if ($token->{'type'} and ($token->{'type'} eq 'bracketed_def_content'
                                or $token->{'type'} eq 'bracketed_inserted')) {
      push @result, [$arg, $token];
      shift @contents;
      $arg = shift (@args);
    } elsif ($token->{'type'}
        and ($token->{'type'} eq 'spaces'
               or $token->{'type'} eq 'spaces_inserted')) {
      if ($token->{'text'}) {
        if ($token->{'text'} =~ /\n$/) {
          $token->{'type'} = 'spaces_at_end';
        }
        push @result, ['spaces', $token];
        shift @contents;
      } else {
        $i++;
        last;
      }
    } elsif ($token->{'type'} and $token->{'type'} eq 'delimiter') {
      push @result, ['delimiter', shift @contents];
    } else {
      my $text_or_cmd = shift @contents;
      push @$argument_content, $text_or_cmd;
    }
    $i++;
    last if (! defined($arg));
  }
  if (scalar(@$argument_content) > 1) {
    my $e = {'contents' => $argument_content,
      'type' => 'def_aggregate'   };
    push @result, [$arg, $e];
    # Replace in the main tree.
    splice @new_contents, $i - scalar(@$argument_content),
           scalar(@$argument_content), $e;
  } elsif (scalar(@$argument_content) == 1) {
    push @result, [$arg, $argument_content->[0]];
  }

  if (scalar(@contents) > 0) {
    splice @new_contents, -scalar(@contents);
  }
  unshift @new_contents, $empty_spaces_after_command
    if $empty_spaces_after_command; 

  @contents = map (_split_delimiters($self, $_), @contents );
  @new_contents = (@new_contents, @contents);

  # Create the part of the def_args array for any arguments.
  my @args_results;
  while (@contents) {
    my $spaces;
    my $next_token = shift @contents;
    if ($next_token->{'type'} and $next_token->{'type'} eq 'spaces') {
      $spaces = $next_token;
      $next_token = shift @contents;
    }
    if (defined($spaces)) {
      if ($spaces->{'text'} =~ /\n$/) {
        $spaces->{'type'} = 'spaces_at_end';
      }
      push @args_results, ['spaces', $spaces]
    }
    last if (!defined($next_token));
    if ($next_token->{'type'} and $next_token->{'type'} eq 'delimiter') {
      push @args_results, ['delimiter', $next_token];
    } else {
      push @args_results, ['arg', $next_token];
    }
  }

  # If a command like @deftypefn, mark the type arguments
  if ($arg_type and $arg_type eq 'argtype') {
    my $next_is_type = 1;
    foreach my $arg(@args_results) {
      if ($arg->[0] eq 'spaces') {
      } elsif ($arg->[0] eq 'delimiter') {
        $next_is_type = 1;
      } elsif ($arg->[1]->{'cmdname'} and $arg->[1]->{'cmdname'} ne 'code') {
        $next_is_type = 1;
      } elsif ($next_is_type) {
        $arg->[0] = 'typearg';
        $next_is_type = 0;
      } else {
        $next_is_type = 1;
      }
    }
  }

  for my $pair (@result, @args_results) {
    $pair->[1]->{'extra'}->{'def_role'} = $pair->[0];
  }

  return [@result, @args_results];
}

# register a label, that is something that may be the target of a reference
# and must be unique in the document.  Corresponds to @node, @anchor and 
# @float second arg.
sub _register_label($$$)
{
  my ($self, $current, $label) = @_;

  push @{$self->{'targets'}}, $current;
  if ($label->{'node_content'}) {
    $current->{'extra'}->{'node_content'} = $label->{'node_content'};
  }
}

# store an index entry.
# $current is the command element.
# $content holds the actual content.
# for index entries and v|ftable items, it is the index entry content, 
# for def, it is the parsed arguments, based on the definition line 
# arguments.
sub _enter_index_entry($$$$$$$)
{
  my ($self, $command_container, $command, $current, $content,
      $content_normalized, $line_nr) = @_;

  $content_normalized = $content if (!defined($content_normalized));

  my $index_name = $self->{'command_index'}->{$command_container};
  my $index = $self->{'index_names'}->{$index_name};

  my $number = (defined($index->{'index_entries'})
                ? (scalar(@{$index->{'index_entries'}}) + 1)
                  : 1);
  my $index_entry = { 'index_name'           => $index_name,
                      'index_at_command'     => $command,
                      'index_type_command'   => $command_container,
                      'content'              => $content,
                      'content_normalized'   => $content_normalized,
                      'command'              => $current,
                      'number'               => $number,
                    };
  if (defined $current->{'extra'}->{'sortas'}) {
    $index_entry->{'sortas'} = $current->{'extra'}->{'sortas'};
  }
  if (@{$self->{'regions_stack'}}) {
    $index_entry->{'region'} = $self->{'regions_stack'}->[-1];
  } elsif ($self->{'current_node'}) {
    $index_entry->{'node'} = $self->{'current_node'};
  } elsif (!$self->{'current_section'}) {
    $self->line_warn(sprintf(__("entry for index `%s' outside of any node"), 
                             $index_name), $line_nr);
  }

  # Skip these as these entries do not refer to the place in the document where 
  # the index commands occurred.
  if (!defined $current->{'extra'}->{'seeentry'}
      and !defined $current->{'extra'}->{'seealso'}) {
    push @{$index->{'index_entries'}}, $index_entry;
  }

  $current->{'extra'}->{'index_entry'} = $index_entry;
}

# close constructs and do stuff at end of line (or end of the document)
sub _end_line($$$);
sub _end_line($$$)
{
  my ($self, $current, $line_nr) = @_;

  my $current_old = $current;

  my $included_file = 0;

  # a line consisting only of spaces.
  if ($current->{'contents'} and @{$current->{'contents'}} 
      and $current->{'contents'}->[-1]->{'type'} 
      and $current->{'contents'}->[-1]->{'type'} eq 'empty_line') {
    print STDERR "END EMPTY LINE\n" if ($self->{'DEBUG'});
    if ($current->{'type'} and $current->{'type'} eq 'paragraph') {
      my $empty_line = pop @{$current->{'contents'}};
      $current = _end_paragraph($self, $current, $line_nr);
      push @{$current->{'contents'}}, $empty_line;
      $empty_line->{'parent'} = $current;
    } elsif ($current->{'type'}
             and $current->{'type'} eq 'preformatted'
             and $current->{'parent'}->{'type'}
             and $current->{'parent'}->{'type'} eq 'menu_entry_description')  {
      my $empty_line = pop @{$current->{'contents'}};
      if ($current->{'type'} eq 'preformatted') {
        my $empty_preformatted = (!@{$current->{'contents'}});
        $current = $current->{'parent'};
        pop @{$current->{'contents'}} if ($empty_preformatted);
      }
      my $context = pop @{$self->{'context_stack'}};
      if ($context ne 'preformatted') {
        $self->_bug_message("context $context instead of preformatted in empty line after menu_entry_description", 
                            $line_nr, $current);
      }
      
      # first parent is menu_entry
      $current = $current->{'parent'}->{'parent'};
      
      push @{$current->{'contents'}}, { 'type' => 'menu_comment',
                                        'parent' => $current,
                                        'contents' => [] };
      $current = $current->{'contents'}->[-1];
      push @{$current->{'contents'}}, { 'type' => 'preformatted',
                                        'parent' => $current,
                                        'contents' => [] };
      $current = $current->{'contents'}->[-1];
      push @{$current->{'contents'}}, { 'type' => 'after_description_line', 
                                        'text' => $empty_line->{'text'},
                                        'parent' => $current };
      push @{$self->{'context_stack'}}, 'preformatted';
      print STDERR "MENU: END DESCRIPTION, OPEN COMMENT\n" if ($self->{'DEBUG'});
    } elsif (!$no_paragraph_contexts{$self->{'context_stack'}->[-1]}) {
      $current = _end_paragraph($self, $current, $line_nr);
    }

  # end of a menu line.
  } elsif ($current->{'type'} 
    and ($current->{'type'} eq 'menu_entry_name'
     or $current->{'type'} eq 'menu_entry_node')) {
    my $empty_menu_entry_node = 0;
    my $end_comment;
    if ($current->{'type'} eq 'menu_entry_node') {
      if (@{$current->{'contents'}} 
          and $current->{'contents'}->[-1]->{'cmdname'}
          and ($current->{'contents'}->[-1]->{'cmdname'} eq 'c' 
            or $current->{'contents'}->[-1]->{'cmdname'} eq 'comment')) {
        $end_comment = pop @{$current->{'contents'}};
      }
      if (!@{$current->{'contents'}} 
           # empty if only the end of line or spaces
           or (@{$current->{'contents'}} == 1 
               and defined($current->{'contents'}->[-1]->{'text'})
               and $current->{'contents'}->[-1]->{'text'} !~ /\S/)) {
        $empty_menu_entry_node = 1;
        push @{$current->{'contents'}}, $end_comment if ($end_comment);
      }
    }
    # we abort the menu entry if there is no node name
    if ($empty_menu_entry_node 
          or $current->{'type'} eq 'menu_entry_name') {
      my $description_or_menu_comment;
      print STDERR "FINALLY NOT MENU ENTRY\n" if ($self->{'DEBUG'});
      my $menu = $current->{'parent'}->{'parent'};
      my $menu_entry = pop @{$menu->{'contents'}};
      if (@{$menu->{'contents'}} and $menu->{'contents'}->[-1]->{'type'}
         and $menu->{'contents'}->[-1]->{'type'} eq 'menu_entry') {
        my $entry = $menu->{'contents'}->[-1];
        my $description;
        foreach my $entry_element (reverse(@{$entry->{'args'}})) {
          if ($entry_element->{'type'} eq 'menu_entry_description') {
            $description = $entry_element;
            last;
          }
        }
        if ($description) {
          $description_or_menu_comment = $description;
        } else {
          # Normally this cannot happen
          $self->_bug_message("No description in menu_entry", 
                               $line_nr, $current);
          push @{$entry->{'args'}}, {'type' => 'menu_entry_description',
                                     'parent' => $entry,
                                     'contents' => [] };
          $description_or_menu_comment = $entry->{'args'}->[-1];
        }
      } elsif (@{$menu->{'contents'}} and $menu->{'contents'}->[-1]->{'type'}
         and $menu->{'contents'}->[-1]->{'type'} eq 'menu_comment') {
        $description_or_menu_comment = $menu->{'contents'}->[-1];
      }
      if ($description_or_menu_comment) {
        $current = $description_or_menu_comment;
        if ($current->{'contents'}->[-1] and $current->{'contents'}->[-1]->{'type'}
          and $current->{'contents'}->[-1]->{'type'} eq 'preformatted') {
          $current = $current->{'contents'}->[-1];
        } else {
          # this should not happen
          $self->_bug_message("description or menu comment not in preformatted", 
                               $line_nr, $current);
          push @{$current->{'contents'}}, {'type' => 'preformatted',
                                    'parent' => $current,
                                    'contents' => [] };
          $current = $current->{'contents'}->[-1];
        }
        push @{$self->{'context_stack'}}, 'preformatted';
      } else {
        push @{$menu->{'contents'}}, {'type' => 'menu_comment',
                                    'parent' => $menu,
                                    'contents' => [] };
        $current = $menu->{'contents'}->[-1];
        push @{$current->{'contents'}}, {'type' => 'preformatted',
                                  'parent' => $current,
                                  'contents' => [] };
        $current = $current->{'contents'}->[-1];
        push @{$self->{'context_stack'}}, 'preformatted';
        print STDERR "THEN MENU_COMMENT OPEN\n" if ($self->{'DEBUG'});
      }
      while (@{$menu_entry->{'args'}}) {
        my $arg = shift @{$menu_entry->{'args'}};
        if (defined($arg->{'text'})) {
          $current = _merge_text($self, $current, $arg->{'text'});
        } else {
          while (@{$arg->{'contents'}}) {
            my $content = shift @{$arg->{'contents'}};
            if (defined($content->{'text'})) {
              $current = _merge_text($self, $current, 
                                    $content->{'text'});
              $content = undef;
            } else {
              $content->{'parent'} = $current;
              push @{$current->{'contents'}}, $content;
            }
          }
        }
        $arg = undef;
      }
      # MENU_COMMENT open
      $menu_entry = undef;
    } else {
      print STDERR "MENU ENTRY END LINE\n" if ($self->{'DEBUG'});
      $current = $current->{'parent'};
      $current = _enter_menu_entry_node($self, $current, $line_nr);
      if (defined($end_comment)) {
        $end_comment->{'parent'} = $current;
        push @{$current->{'contents'}}, $end_comment;
      }
    }
  # def line
  } elsif ($current->{'parent'}
            and $current->{'parent'}->{'type'}
            and $current->{'parent'}->{'type'} eq 'def_line') {
    my $def_context = pop @{$self->{'context_stack'}};
    if ($def_context ne 'def') {
      $self->_bug_message("context $def_context instead of def", 
                          $line_nr, $current);
      die; 
    }
    my $def_command = $current->{'parent'}->{'extra'}->{'def_command'};
    my $arguments = _parse_def($self, $def_command, $current);
    if (scalar(@$arguments)) {
      #$current->{'parent'}->{'extra'}->{'def_args'} = $arguments;
      my $def_parsed_hash;
      foreach my $arg (@$arguments) {
        die if (!defined($arg->[0]));
        last if ($arg->[0] eq 'arg' or $arg->[0] eq 'typearg' 
                  or $arg->[0] eq 'delimiter');
        next if ($arg->[0] eq 'spaces');
        $def_parsed_hash->{$arg->[0]} = $arg->[1];
      }
      $current->{'parent'}->{'extra'}->{'def_parsed_hash'} = $def_parsed_hash;
      # do an standard index entry tree
      my $index_entry;
      if (defined($def_parsed_hash->{'name'})) {
        $index_entry = $def_parsed_hash->{'name'}
         # empty bracketed
          unless ($def_parsed_hash->{'name'}->{'type'}
                  and $def_parsed_hash->{'name'}->{'type'} eq 'bracketed_def_content'
                  and (!$def_parsed_hash->{'name'}->{'contents'}
                       or (!scalar(@{$def_parsed_hash->{'name'}->{'contents'}}))
                       or (scalar(@{$def_parsed_hash->{'name'}->{'contents'}}) == 1
                          and defined($def_parsed_hash->{'name'}->{'contents'}->[0]->{'text'})
                          and $def_parsed_hash->{'name'}->{'contents'}->[0]->{'text'} !~ /\S/)));
      }
      if (defined($index_entry)) {
        my $index_contents_normalized;
        if ($def_parsed_hash->{'class'}) {
          # Delay getting the text until Texinfo::Structuring::sort_index_keys
          # in order to avoid using gdt.
          # We need to store the language as well in case there are multiple
          # languages in the document.
          if ($command_index{$def_command} eq 'fn'
              or $command_index{$def_command} eq 'vr'
                  and $def_command ne 'defcv') {
            undef $index_entry;
            $current->{'parent'}->{'extra'}->{'documentlanguage'}
                     = $self->{'documentlanguage'};
          }
        }
        my $index_contents;
        if ($index_entry) {
          $index_contents_normalized = [$index_entry];
          $index_contents = [$index_entry];
        }

        _enter_index_entry($self, 
          $current->{'parent'}->{'extra'}->{'def_command'},
          $current->{'parent'}->{'extra'}->{'original_def_cmdname'},
          $current->{'parent'}, $index_contents, 
          $index_contents_normalized, $line_nr);
      } else {
        $self->_command_warn($current->{'parent'}, $line_nr, 
           __('missing name for @%s'),
           $current->{'parent'}->{'extra'}->{'original_def_cmdname'});
      }
    } else {
      $self->_command_warn($current->{'parent'}, $line_nr, 
         __('missing category for @%s'),
         $current->{'parent'}->{'extra'}->{'original_def_cmdname'});
    }
    $current = $current->{'parent'}->{'parent'};
    $current = _begin_preformatted($self, $current);

  # other block command lines
  } elsif ($current->{'type'}
            and $current->{'type'} eq 'block_line_arg') {
    my $empty_text;
    my $context = pop @{$self->{'context_stack'}};
    if ($context ne 'line') {
      $self->_bug_message("context $context instead of line in block_line_arg", 
                          $line_nr, $current);
    }
    # @multitable args
    if ($current->{'parent'}->{'cmdname'}
               and $current->{'parent'}->{'cmdname'} eq 'multitable') {
      # parse the prototypes and put them in a special arg
      my @prototype_row;
      foreach my $content (@{$current->{'contents'}}) {
        if ($content->{'type'} and $content->{'type'} eq 'bracketed') {
          push @prototype_row, { 'contents' => $content->{'contents'},
                                 'type' => 'bracketed_multitable_prototype'};
        } elsif ($content->{'text'}) {
          # TODO: this should be a warning or an error - all prototypes
          # on a @multitable line should be in braces, as documented in the
          # Texinfo manual.
          if ($content->{'text'} =~ /\S/) {
            foreach my $prototype (split /\s+/, $content->{'text'}) {
              push @prototype_row, { 'text' => $prototype, 
                            'type' => 'row_prototype' } unless ($prototype eq '');
            }
          }
        } else {
          if (!$content->{'cmdname'}
                or ($content->{'cmdname'} ne 'c'
                    and $content->{'cmdname'} ne 'comment')) {
            $self->_command_warn($current, $line_nr, 
                __("unexpected argument on \@%s line: %s"),
                     $current->{'parent'}->{'cmdname'}, 
                     Texinfo::Convert::Texinfo::convert($content));
          }
        }
      }
      
      my $multitable = $current->{'parent'};
      $multitable->{'extra'}->{'max_columns'} = scalar(@prototype_row);
      if (!scalar(@prototype_row)) {
        $self->_command_warn($multitable, $line_nr, 
                             __("empty multitable"));
      }
      $multitable->{'extra'}->{'prototypes'} = \@prototype_row;
    }
    _isolate_last_space($self, $current);
    $current = $current->{'parent'};
    delete $current->{'remaining_args'};
    # don't consider empty argument of block @-commands as argument,
    # reparent them as contents
    if ($current->{'args'}->[0]->{'contents'}->[0] 
         and $current->{'args'}->[0]->{'contents'}->[0]->{'type'}
         and $current->{'args'}->[0]->{'contents'}->[0]->{'type'} eq 'empty_line_after_command')
    {
      my $empty_text = $current->{'args'}->[0]->{'contents'}->[0];
      $empty_text->{'parent'} = $current;
      unshift @{$current->{'contents'}}, $empty_text;
      delete $current->{'args'};
    }

    # @float args
    if ($current->{'cmdname'} and $current->{'cmdname'} eq 'float') {
      $current->{'line_nr'} = $line_nr;
      my $type = '';
      my $float_label;
      if ($current->{'args'} and $current->{'args'}->[1]) {
        $float_label = _parse_node_manual($current->{'args'}->[1]);
        _check_internal_node($self, $float_label, $line_nr);
      }
      _register_label($self, $current, $float_label);
      _parse_float_type($current);
      $type = $current->{'extra'}->{'type'}->{'normalized'};
      push @{$self->{'floats'}->{$type}}, $current;
      $current->{'extra'}->{'float_section'} = $self->{'current_section'} 
        if (defined($self->{'current_section'}));
    }

    if ($current->{'cmdname'} 
          and $block_item_commands{$current->{'cmdname'}}) {
      if ($current->{'cmdname'} eq 'enumerate') {
        my $spec = 1;
        if ($current->{'args'} and $current->{'args'}->[0]
            and $current->{'args'}->[0]->{'contents'}
            and @{$current->{'args'}->[0]->{'contents'}}) {
          if (scalar(@{$current->{'args'}->[0]->{'contents'}}) > 1) {
            $self->_command_error($current, $line_nr, 
                        __("superfluous argument to \@%s"),
                        $current->{'cmdname'});
          }
          my $arg = $current->{'args'}->[0]->{'contents'}->[0];
          if (!defined($arg->{'text'}) or $arg->{'text'} !~ /^(([[:digit:]]+)|([[:alpha:]]+))$/) {
            $self->_command_error($current, $line_nr, 
                        __("bad argument to \@%s"),
                        $current->{'cmdname'});
          } else {
            $spec = $arg->{'text'};
          }
        }
        $current->{'extra'}->{'enumerate_specification'} = $spec;
      } elsif ($item_line_commands{$current->{'cmdname'}}) {
        if (!$current->{'extra'} 
            or !$current->{'extra'}->{'command_as_argument'}) {
          $self->_command_error($current, $line_nr, 
              __("%s requires an argument: the formatter for %citem"),
              $current->{'cmdname'}, ord('@'));
        } elsif (!$brace_commands{$current->{'extra'}->{'command_as_argument'}->{'cmdname'}}) {
          $self->_command_error($current, $line_nr, 
              __("command \@%s not accepting argument in brace should not be on \@%s line"),
              $current->{'extra'}->{'command_as_argument'}->{'cmdname'},
              $current->{'cmdname'});
          delete $current->{'extra'}->{'command_as_argument'};
        }
      }
      # This code checks that the command_as_argument of the @itemize
      # is alone on the line, otherwise it is not a command_as_argument.
      if ($current->{'extra'}
          and $current->{'extra'}->{'command_as_argument'}
          and $current->{'cmdname'} eq 'itemize') {
        my @args = @{$current->{'args'}->[0]->{'contents'}};
        while (@args) {
          my $arg = shift @args;
          last if ($arg eq $current->{'extra'}->{'command_as_argument'});
        }
        while (@args) {
          my $arg = shift @args;
          if (!(($arg->{'cmdname'} 
               and ($arg->{'cmdname'} eq 'c' 
                     or $arg->{'cmdname'} eq 'comment'))
               or (defined($arg->{'text'}) and $arg->{'text'} !~ /\S/))) {
            delete $current->{'extra'}->{'command_as_argument'}->{'type'};
            delete $current->{'extra'}->{'command_as_argument'};
            last;
          }
        }
      }
      if ($current->{'extra'}
          and $current->{'extra'}->{'command_as_argument'}
          and $accent_commands{$current->{'extra'}->{'command_as_argument'}->{'cmdname'}}
          and ($current->{'cmdname'} eq 'itemize' 
               or $item_line_commands{$current->{'cmdname'}})) {
        $self->_command_warn($current, $line_nr, 
              __("accent command `\@%s' not allowed as \@%s argument"),
              $current->{'extra'}->{'command_as_argument'}->{'cmdname'}, 
              $current->{'cmdname'});
        delete $current->{'extra'}->{'command_as_argument'};
      }
      if ($current->{'cmdname'} eq 'itemize'
          and (!$current->{'args'}
            or !$current->{'args'}->[0]
            or !$current->{'args'}->[0]->{'contents'}
            or !@{$current->{'args'}->[0]->{'contents'}})) {
        my $inserted =  { 'cmdname' => 'bullet', 
                          'contents' => [],
                          'type' => 'command_as_argument_inserted',
                          'parent' => $current };
        unshift @{$current->{'args'}}, $inserted;
        $current->{'extra'}->{'command_as_argument'} = $inserted;
      } elsif ($item_line_commands{$current->{'cmdname'}} and
              !$current->{'extra'}->{'command_as_argument'}) {
        my $inserted =  { 'cmdname' => 'asis', 
                          'contents' => [],
                          'type' => 'command_as_argument_inserted',
                          'parent' => $current };
        unshift @{$current->{'args'}}, $inserted;
        $current->{'extra'}->{'command_as_argument'} = $inserted;
      }
      push @{$current->{'contents'}}, { 'type' => 'before_item',
         'contents' => [], 'parent', $current };
      $current = $current->{'contents'}->[-1];
    }
    if ($current->{'cmdname'} and $menu_commands{$current->{'cmdname'}}) {
      push @{$current->{'contents'}}, {'type' => 'menu_comment',
                                       'parent' => $current,
                                       'contents' => [] };
      $current = $current->{'contents'}->[-1];
      print STDERR "MENU_COMMENT OPEN\n" if ($self->{'DEBUG'});
      push @{$self->{'context_stack'}}, 'preformatted';
    }
    $current = _begin_preformatted($self, $current);

  # if we are after a @end verbatim, we must restart a preformatted if needed,
  # since there is no @end command explicitly associated to raw commands
  # it won't be done elsewhere.
  } elsif ($current->{'contents'}
           and $current->{'contents'}->[-1]
           and $current->{'contents'}->[-1]->{'type'}
           and $current->{'contents'}->[-1]->{'type'} eq 'empty_line_after_command'
           and $current->{'contents'}->[-2]
           and $current->{'contents'}->[-2]->{'cmdname'}
           and $current->{'contents'}->[-2]->{'cmdname'} eq 'verbatim') {
    $current = _begin_preformatted($self, $current);
  # misc command line arguments
  # Never go here if skipline/noarg/...
  } elsif ($current->{'type'} 
           and $current->{'type'} eq 'line_arg') {
    my $context = pop @{$self->{'context_stack'}};
    if ($context ne 'line') {
      $self->_bug_message("context $context instead of line in line_arg", 
                          $line_nr, $current);
    }
    _isolate_last_space($self, $current);

    # first parent is the @command, second is the parent
    $current = $current->{'parent'};
    my $misc_cmd = $current;
    my $command = $current->{'cmdname'};
    my $end_command;
    print STDERR "MISC END \@$command\n" if ($self->{'DEBUG'});

    if ($self->{'line_commands'}->{$command} =~ /^\d$/) {
      my $args = _parse_line_command_args($self, $current, $line_nr);
      $current->{'extra'}->{'misc_args'} = $args if (defined($args));
      if ($command eq 'validatemenus') {
        if ($args and $args->[0]) {
          my $arg = $args->[0];
          if ($arg eq 'on') {
            $self->{'validatemenus'} = 1;
          } elsif ($arg eq 'off') {
            $self->{'validatemenus'} = 0;
          }
        }
      }
    } elsif ($self->{'line_commands'}->{$command} eq 'text') {
      my $text = '';
      my $superfluous_arg = 0;
      for my $c (@{$current->{'args'}->[0]->{'contents'}}) {
        # Allow @@, @{ and @} to give a way for @, { and } to appear in
        # filenames (although it's not a good idea to use these characters
        # in filenames).
        if ($c->{'text'}) {
          $text .= $c->{'text'};
        } elsif ($c->{'cmdname'} and $c->{'cmdname'} eq '@') {
          $text .= '@';
        } elsif ($c->{'cmdname'} and $c->{'cmdname'} eq '{') {
          $text .= '{';
        } elsif ($c->{'cmdname'} and $c->{'cmdname'} eq '}') {
          $text .= '}';
        } else {
          $superfluous_arg = 1;
        }
      }
      if ($text eq '') {
        if (not $superfluous_arg) {
          $self->_command_warn($current, $line_nr, 
                               __("\@%s missing argument"), $command);
        }
        # Otherwise an error message is issued below.
        $current->{'extra'}->{'missing_argument'} = 1;
      } else {
        $current->{'extra'}->{'text_arg'} = $text;
        if ($command eq 'end') {
          # REMACRO
          my $line = $text;
          if ($line =~ s/^([[:alnum:]][[:alnum:]-]+)//) {
            $end_command = $1;
            
            if (!exists $block_commands{$end_command}) {
              $self->_command_warn($current, $line_nr, 
                             __("unknown \@end %s"), $end_command);
              $end_command = undef;
            } else {
              print STDERR "END BLOCK $end_command\n" if ($self->{'DEBUG'});
              if ($block_commands{$end_command} eq 'conditional') {
                if (@{$self->{'conditionals_stack'}}
                  and $self->{'conditionals_stack'}->[-1] eq $end_command) {
                  pop @{$self->{'conditionals_stack'}};
                } else {
                  $self->_command_error($current, $line_nr, 
                             __("unmatched `%c%s'"), ord('@'), 'end');
                  $end_command = undef;
                }
              }
              $current->{'extra'}->{'command_argument'} = $end_command
                if (defined($end_command));
            }
            if (($superfluous_arg or $line =~ /\S/)
                and defined($end_command)) {
              my $texi_line 
                = Texinfo::Convert::Texinfo::convert($current->{'args'}->[0]);
              $texi_line =~ s/^\s*([[:alnum:]][[:alnum:]-]+)//;
              $self->_command_error($current, $line_nr, 
                             __("superfluous argument to \@%s %s: %s"),
                             $command, $end_command, $texi_line);
              $superfluous_arg = 0; # Don't issue another error message below.
            }
          } else {
            $self->_command_error($current, $line_nr,
                              __("bad argument to \@%s: %s"),
                              $command, $line);
          }
        } elsif ($superfluous_arg) {
          # An error message is issued below.
        } elsif ($command eq 'include') {
          my $file = Texinfo::Common::locate_include_file($self, $text) ;
          if (defined($file)) {
            my $filehandle = do { local *FH };
            if (_open_in ($self, $filehandle, $file)) {
              $included_file = 1;
              print STDERR "Included $file($filehandle)\n" if ($self->{'DEBUG'});
              my ($directories, $suffix);
              ($file, $directories, $suffix) = fileparse($file)
                  if ($self->{'TEST'});
              unshift @{$self->{'input'}}, { 
                'name' => $file,
                'line_nr' => 0,
                'pending' => [],
                'fh' => $filehandle };
            } else {
              $self->_command_error($current, $line_nr,
                              __("\@%s: could not open %s: %s"),
                              $command, $text, $!);
            }
          } else {
            $self->_command_error($current, $line_nr,
                              __("\@%s: could not find %s"),
                              $command, $text);
          }
        } elsif ($command eq 'verbatiminclude') {
          $current->{'extra'}->{'input_perl_encoding'}
                          = $self->{'info'}->{'input_perl_encoding'}
            if defined $self->{'info'}->{'input_perl_encoding'};
        } elsif ($command eq 'documentencoding') {
          my ($texinfo_encoding, $perl_encoding, $input_encoding)
            = Texinfo::Encoding::encoding_alias($text);
          $self->_command_warn($current, $line_nr,
                 __("encoding `%s' is not a canonical texinfo encoding"),
                               $text)
            if (!$texinfo_encoding or $texinfo_encoding ne lc($text));
          if ($input_encoding) {
            $current->{'extra'}->{'input_encoding_name'} = $input_encoding;
          }
          if (!$perl_encoding) {
            $self->_command_warn($current, $line_nr,
                 __("unrecognized encoding name `%s'"), $text);
          } else {
            $current->{'extra'}->{'input_perl_encoding'} = $perl_encoding;

            if ($input_encoding) {
              $self->{'info'}->{'input_encoding_name'} = $input_encoding;
            }

            $self->{'info'}->{'input_perl_encoding'} = $perl_encoding;
            foreach my $input (@{$self->{'input'}}) {
              binmode($input->{'fh'}, ":encoding($perl_encoding)") if ($input->{'fh'});
            }
          }
        } elsif ($command eq 'documentlanguage') {
          my @messages = Texinfo::Common::warn_unknown_language($text);
          foreach my $message(@messages) {
            $self->_command_warn($current, $line_nr, $message);
          }
          if (!$self->{'set'}->{'documentlanguage'}) {
            $self->{'documentlanguage'} = $text;
          }
        }
      }
      if ($superfluous_arg) {
        my $texi_line 
          = Texinfo::Convert::Texinfo::convert($current->{'args'}->[0]);
        $texi_line =~ s/^\s*//;
        $texi_line =~ s/\s*$//;

        $self->_command_error($current, $line_nr, 
                       __("bad argument to \@%s: %s"),
                       $command, $texi_line);
        
      }
    } elsif ($command eq 'node') {
      foreach my $arg (@{$current->{'args'}}) {
        my $node = _parse_node_manual($arg);
        push @{$current->{'extra'}->{'nodes_manuals'}}, $node;
      }
      _check_internal_node($self, $current->{'extra'}->{'nodes_manuals'}->[0],
                           $line_nr);
     _register_label($self, $current, 
                   $current->{'extra'}->{'nodes_manuals'}->[0]);
     $self->{'current_node'} = $current;
    } elsif ($command eq 'listoffloats') {
      _parse_float_type($current);
    } else {
      # Handle all the other 'line' commands.  Here just check that they 
      # have an argument.  Empty @top is allowed
      if (!@{$current->{'args'}->[0]->{'contents'}} and $command ne 'top') {
        $self->_command_warn($current, $line_nr,
               __("\@%s missing argument"), $command);
        $current->{'extra'}->{'missing_argument'} = 1;
      } else {
        if (($command eq 'item' or $command eq 'itemx')
            and $current->{'parent'}->{'cmdname'}
            and $self->{'command_index'}->{$current->{'parent'}->{'cmdname'}}) {
          _enter_index_entry($self, $current->{'parent'}->{'cmdname'}, 
                             $command, $current,
                             $current->{'args'}->[0]->{'contents'},
                             undef, $line_nr);
        } elsif ($self->{'command_index'}->{$current->{'cmdname'}}) {
          _enter_index_entry($self, $current->{'cmdname'}, 
                             $current->{'cmdname'}, $current,
                             $current->{'args'}->[0]->{'contents'},
                             undef, $line_nr);
          $current->{'type'} = 'index_entry_command';
        }
      }
    }
    $current = $current->{'parent'};
    if ($end_command) {
      print STDERR "END COMMAND $end_command\n" if ($self->{'DEBUG'});
      my $end = pop @{$current->{'contents'}};
      if ($block_commands{$end_command} ne 'conditional') {
        my $closed_command;
        ($closed_command, $current)
          = _close_commands($self, $current, $line_nr, $end_command);
        my $inline_copying;
        if ($closed_command) {
          $closed_command->{'extra'}->{'end_command'} = $misc_cmd;
          _close_command_cleanup($self, $closed_command);
          $end->{'parent'} = $closed_command;

          push @{$closed_command->{'contents'}}, $end;

          # closing a menu command, but still in a menu. Open a menu_comment
          if ($menu_commands{$closed_command->{'cmdname'}} 
              and $self->{'context_stack'}->[-1] eq 'menu') {
            print STDERR "CLOSE MENU but still in menu context\n"
              if ($self->{'DEBUG'});
            push @{$current->{'contents'}}, {'type' => 'menu_comment',
                                             'parent' => $current,
                                             'contents' => [] };
            $current = $current->{'contents'}->[-1];
            push @{$self->{'context_stack'}}, 'preformatted';
          }
        } else {
          # block command not found for @end
        }
        $current = _begin_preformatted($self, $current)
          if ($close_preformatted_commands{$end_command});
      }
    } else {
      $current = _begin_preformatted($self, $current) 
        if ($close_preformatted_commands{$command});
    }
    # if a file was included, remove completly the include file command.
    # Also ignore @setfilename in included file, as said in the manual.
    if ($included_file or ($command eq 'setfilename'
                           and scalar(@{$self->{'input'}}) > 1)) {
      # TODO keep the information with sourcemark
      pop @{$current->{'contents'}};
    } elsif ($command eq 'setfilename'
             and ($self->{'current_node'} or $self->{'current_section'})) {
      $self->_command_warn($misc_cmd, $line_nr,
               __("\@%s after the first element"), $command);
    # columnfractions 
    } elsif ($command eq 'columnfractions') {
      # in a multitable, we are in a block_line_arg
      if (!$current->{'parent'} or !$current->{'parent'}->{'cmdname'} 
                   or $current->{'parent'}->{'cmdname'} ne 'multitable') {
        $self->_command_error($current, $line_nr,
               __("\@%s only meaningful on a \@multitable line"), 
               $command);
      } else {
        # This is the multitable block_line_arg line context
        my $context = pop @{$self->{'context_stack'}};
        if ($context ne 'line') {
          $self->_bug_message("context $context instead of line for multitable", 
                               $line_nr, $current);
        }
        $current = $current->{'parent'};
        $current->{'extra'}->{'max_columns'} = 0;
        if (defined($misc_cmd->{'extra'}->{'misc_args'})) {
          $current->{'extra'}->{'max_columns'} = 
            scalar(@{$misc_cmd->{'extra'}->{'misc_args'}});
          $current->{'extra'}->{'columnfractions'} = $misc_cmd;
        }
        push @{$current->{'contents'}}, { 'type' => 'before_item',
           'contents' => [], 'parent', $current };
        $current = $current->{'contents'}->[-1];
      }
    } elsif ($root_commands{$command}) {
      $current = $current->{'contents'}->[-1];
      delete $current->{'remaining_args'};

      # associate the section (not part) with the current node.
      if ($command ne 'node' and $command ne 'part') {
        if ($self->{'current_node'}
           and !$self->{'current_node'}->{'extra'}->{'associated_section'}) {
          $self->{'current_node'}->{'extra'}->{'associated_section'} = $current;
          $current->{'extra'}->{'associated_node'} = $self->{'current_node'};
        }
        if ($self->{'current_part'}) {
          $current->{'extra'}->{'associated_part'} = $self->{'current_part'};
          $self->{'current_part'}->{'extra'}->{'part_associated_section'}
                                                   = $current;
          if ($current->{'cmdname'} eq 'top') {
            $self->line_warn("\@part should not be associated with \@top",
                             $self->{'current_part'}->{'line_nr'});
          }
          delete $self->{'current_part'};
        }
        $self->{'current_section'} = $current;
      } elsif ($command eq 'part') {
        $self->{'current_part'} = $current;
        if ($self->{'current_node'}
           and !$self->{'current_node'}->{'extra'}->{'associated_section'}) {
          $self->line_warn (sprintf(__(
           "\@node precedes \@%s, but parts may not be associated with nodes"), 
                                    $command), $line_nr);
        }
      }
    }
   # do that last in order to have the line processed if one of the above
   # case is also set.
  } elsif (
      $current->{'contents'} 
      and (scalar(@{$current->{'contents'}}) == 1
           and (($current->{'contents'}->[-1]->{'type'}
               and $current->{'contents'}->[-1]->{'type'} eq 'empty_line_after_command'))
          or (scalar(@{$current->{'contents'}}) == 2
               and $current->{'contents'}->[-1]->{'cmdname'}
               and ($current->{'contents'}->[-1]->{'cmdname'} eq 'c'
                    or $current->{'contents'}->[-1]->{'cmdname'} eq 'comment')
               and $current->{'contents'}->[-2] 
               and $current->{'contents'}->[-2]->{'type'}
               and $current->{'contents'}->[-2]->{'type'} eq 'empty_line_after_command'))) {
    # empty line after a @menu or before a preformatted. Reparent to the menu
    # or other format
    if ($current->{'type'}
        and $preformatted_contexts{$current->{'type'}}) {
      my $parent = $current->{'parent'};
      if ($parent->{'type'} and $parent->{'type'} eq 'menu_comment'
          and scalar(@{$parent->{'contents'}}) == 1) {
        $parent = $parent->{'parent'};
      }
      my $to_reparent = pop @{$parent->{'contents'}};
      print STDERR "LINE AFTER COMMAND IN PREFORMATTED ($to_reparent->{'type'})\n" if ($self->{'DEBUG'});
      while (@{$current->{'contents'}}) {
        my $content = shift @{$current->{'contents'}};
        $content->{'parent'} = $parent;
        push @{$parent->{'contents'}}, $content;
      }
      push @{$parent->{'contents'}}, $to_reparent;
    }
  }

  # this happens if there is a nesting of line @-commands on a line.
  # they are reprocessed here.
  if ($self->{'context_stack'}->[-1] eq 'line' 
            or $self->{'context_stack'}->[-1] eq 'def') {
    print STDERR "Still opened line command $self->{'context_stack'}->[-1]:"._print_current($current) 
      if ($self->{'DEBUG'});
    if ($self->{'context_stack'}->[-1] eq 'def') {
      while ($current->{'parent'} and !($current->{'parent'}->{'type'}
            and $current->{'parent'}->{'type'} eq 'def_line')) {
        $current = _close_current($self, $current, $line_nr);
      }
    } else {
      while ($current->{'parent'} and !($current->{'type'}
             and ($current->{'type'} eq 'block_line_arg'
                  or $current->{'type'} eq 'line_arg'))) {
        $current = _close_current($self, $current, $line_nr);
      }
    }

    # check for infinite loop bugs...
    if ($current eq $current_old) {
      my $indent = '- ';
      my $tree_msg = $indent . _print_current($current);
      while ($current->{'parent'}) {
        $indent = '-'.$indent;
        $current = $current->{'parent'};
        $tree_msg .= $indent . _print_current($current);
      }
      $self->_bug_message("Nothing closed while a line context remains\n$tree_msg",
                           $line_nr);
      die;
    }

    $current = $self->_end_line($current, $line_nr);
  }
  return $current;
}

# $command may be undef if we are after a wrong misc command such as 
# a buggy @tab.
sub _start_empty_line_after_command($$$) {
  my ($line, $current, $command) = @_;

  $line =~ s/^([^\S\r\n]*)//;
  push @{$current->{'contents'}}, { 'type' => 'empty_line_after_command',
                                    'text' => $1,
                                    'parent' => $current, 
                                  };
  if (defined($command)) {
    $current->{'contents'}->[-1]->{'extra'} = {'command' => $command};
  }
  return $line;
}

sub _check_empty_node($$$$)
{
  my ($self, $parsed_node, $command, $line_nr) = @_;

  if (!defined($parsed_node) or !$parsed_node->{'node_content'}) {
    $self->line_error (sprintf(__("empty argument in \@%s"),
                $command), $line_nr);
    return 0;
  } else {
    return 1;
  }
}

sub _check_internal_node($$$)
{
  my ($self, $parsed_node, $line_nr) = @_;

  if ($parsed_node and $parsed_node->{'manual_content'}) {
    $self->line_error (sprintf(__("syntax for an external node used for `%s'"),
          Texinfo::Structuring::node_extra_to_texi($parsed_node)), $line_nr)
  }
}

sub _check_node_label($$$$)
{
  my ($self, $parsed_node, $command, $line_nr) = @_;

  _check_internal_node($self, $parsed_node, $line_nr);
  return _check_empty_node($self, $parsed_node, $command, $line_nr);
}

sub _register_extra_menu_entry_information($$;$)
{
  my ($self, $current, $line_nr) = @_;

  foreach my $arg (@{$current->{'args'}}) {
    if ($arg->{'type'} eq 'menu_entry_name') {
      $current->{'extra'}->{'menu_entry_name'} = $arg;
      my $normalized_menu_entry_name = 
        Texinfo::Convert::NodeNameNormalization::normalize_node($arg);
      if ($normalized_menu_entry_name !~ /[^-]/) {
        $self->line_warn(sprintf(__("empty menu entry name in `%s'"),
          Texinfo::Convert::Texinfo::convert($current)), $line_nr);
      }
    } elsif ($arg->{'type'} eq 'menu_entry_node') {
      _isolate_last_space($self, $arg);
      my $parsed_entry_node = _parse_node_manual($arg);
      if (! defined($parsed_entry_node)) {
        if ($self->{'SHOW_MENU'}) {
          $self->line_error (__("empty node name in menu entry"), $line_nr);
        }
      } else {
        delete $parsed_entry_node->{'normalized'};
        $current->{'extra'}->{'menu_entry_node'} = $parsed_entry_node;
      }
    } elsif ($arg->{'type'} eq 'menu_entry_description') {
      $current->{'extra'}->{'menu_entry_description'} = $arg;
    }
  } 
}

sub _enter_menu_entry_node($$$)
{
  my ($self, $current, $line_nr) = @_;

  my $description = { 'type' => 'menu_entry_description',
                      'contents' => [],
                      'parent' => $current };
  push @{$current->{'args'}}, $description;
  _register_extra_menu_entry_information($self, $current, $line_nr);
  $current->{'line_nr'} = $line_nr;
  push @{$self->{'internal_references'}}, $current;

  $current = $description;
  push @{$current->{'contents'}}, {'type' => 'preformatted',
                                   'parent' => $current,
                                   'contents' => [] };
  $current = $current->{'contents'}->[-1];
  push @{$self->{'context_stack'}}, 'preformatted';
  return $current;
}

sub _command_with_command_as_argument($)
{
  my $current = shift;
  return ($current and $current->{'type'}
      and $current->{'type'} eq 'block_line_arg'
      and $current->{'parent'} 
      and $current->{'parent'}->{'cmdname'} and
     ($current->{'parent'}->{'cmdname'} eq 'itemize'
      or $item_line_commands{$current->{'parent'}->{'cmdname'}})
      and scalar(@{$current->{'contents'}}) == 1);
}

sub _is_index_element {
  my ($self, $element) = @_;

  if (!$element->{'cmdname'}
        or (!$self->{'command_index'}->{$element->{'cmdname'}}
             and $element->{'cmdname'} ne 'subentry')) {
    return 0;
  }
  return 1;
}

# This combines several regular expressions used in '_parse_texi' to
# look at what is next on the remaining part of the line.
# NOTE - this sub has an XS override
sub _parse_texi_regex {
  my ($line) = @_;

  my ($at_command, $open_brace, $asterisk, $single_letter_command,
      $separator_match, $misc_text)
    = ($line =~ /^\@([[:alnum:]][[:alnum:]-]*)
                |^(\{)
                |^(\*)
                |^\@(["'~\@&\}\{,\.!\? \t\n\*\-\^`=:\|\/\\])
                |^([{}@,:\t.\f])
                |^([^{}@,:\t.\n\f]+)
                /x);

  if ($open_brace) {
    $separator_match = $open_brace;
  } elsif ($asterisk) {
    ($misc_text) = ($line =~ /^([^{}@,:\t.\n\f]+)/);
  }

  return ($at_command, $open_brace, $asterisk, $single_letter_command,
    $separator_match, $misc_text);
}

sub _check_line_directive {
  my ($self, $line, $line_nr) = @_;

  if ($self->{'CPP_LINE_DIRECTIVES'}
      and defined($line_nr->{'file_name'})
      and $line_nr->{'file_name'} ne ''
      and !$line_nr->{'macro'}
      and $line =~ /^\s*#\s*(line)? (\d+)(( "([^"]+)")(\s+\d+)*)?\s*$/) {
    _save_line_directive ($self, $2, $5);
    return 1;
  }
  return 0;
}

# Check whether $COMMAND can appear within $CURRENT->{'parent'}.
sub _check_valid_nesting {
  my ($self, $current, $command, $line_nr) = @_;

  my $invalid_parent;
  # error messages for forbidden constructs, like @node in @r, 
  # block command on line command, @xref in @anchor or node...
  if ($current->{'parent'}) { 
    if ($current->{'parent'}->{'cmdname'}) {
      if (defined($self->{'valid_nestings'}->{$current->{'parent'}->{'cmdname'}})
          and !$self->{'valid_nestings'}->{$current->{'parent'}->{'cmdname'}}->{$command}
          # we make sure that we are on a root @-command line and 
          # not in contents
          and (!$root_commands{$current->{'parent'}->{'cmdname'}}
               or ($current->{'type'}
                   and $current->{'type'} eq 'line_arg'))
          # we make sure that we are on a block @-command line and 
          # not in contents
          and (!($block_commands{$current->{'parent'}->{'cmdname'}})
               or ($current->{'type'} 
                    and $current->{'type'} eq 'block_line_arg'))
          # we make sure that we are on an @item/@itemx line and
          # not in an @enumerate, @multitable or @itemize @item.
          and (($current->{'parent'}->{'cmdname'} ne 'itemx'
               and $current->{'parent'}->{'cmdname'} ne 'item')
               or ($current->{'type'}
                        and $current->{'type'} eq 'line_arg'))) {
        $invalid_parent = $current->{'parent'}->{'cmdname'};
      }
    } elsif ($self->{'context_stack'}->[-1] eq 'def'
      # FIXME instead of hardcoding in_full_line_commands_no_refs
      # it would be better to use the parent command valid_nesting.
             and !$in_full_line_commands_no_refs{$command}) {
      my $def_block = $current;
      while ($def_block->{'parent'} and (!$def_block->{'parent'}->{'type'} 
                           or $def_block->{'parent'}->{'type'} ne 'def_line')) {
        $def_block = $def_block->{'parent'};
      }

      $invalid_parent = $def_block->{'parent'}->{'parent'}->{'cmdname'};
    }
  }

  if (defined($invalid_parent)) {
    $self->line_warn(sprintf(__("\@%s should not appear in \@%s"), 
              $command, $invalid_parent), $line_nr);
  }
}


# the main subroutine
sub _parse_texi($;$)
{
  my ($self, $root) = @_;

  $root = { 'contents' => [], 'type' => 'text_root' } if (!defined($root));
  my $current = $root;

  my $line_nr;
  
 NEXT_LINE:
  while (1) {
    my $line;
    ($line, $line_nr) = _next_text($self, $line_nr);
    last if (!defined($line));

    if ($self->{'DEBUG'}) {
      my $line_text = '';
      $line_text = "$line_nr->{'line_nr'}.$line_nr->{'macro'}" if ($line_nr);
      print STDERR "NEW LINE(".join('|', @{$self->{'context_stack'}}).":@{$self->{'conditionals_stack'}}:$line_text): $line";
      #print STDERR "CONTEXT_STACK ".join('|',@{$self->{'context_stack'}})."\n";
    }

    if (not 
        # raw format or verb
          (($current->{'cmdname'}
           and $block_commands{$current->{'cmdname'}}
            and ($block_commands{$current->{'cmdname'}} eq 'raw'
                 or $block_commands{$current->{'cmdname'}} eq 'conditional'))
          or 
           ($current->{'parent'} and $current->{'parent'}->{'cmdname'}
            and $current->{'parent'}->{'cmdname'} eq 'verb')
          )
        # not def line
        and $self->{'context_stack'}->[-1] ne 'def') {
      next NEXT_LINE if _check_line_directive ($self, $line, $line_nr);
      print STDERR "BEGIN LINE\n" if ($self->{'DEBUG'});

      if ($current->{'contents'}
          and $current->{'contents'}->[-1]
          and $current->{'contents'}->[-1]->{'type'}
          and $current->{'contents'}->[-1]->{'type'}
               eq 'empty_spaces_before_argument') {
        # Remove this element and update 'extra' values.
        # FIXME: should we continue with this element instead?
        _abort_empty_line($self, $current);
      }
      $line =~ s/^([^\S\r\n]*)//;
      push @{$current->{'contents'}}, { 'type' => 'empty_line', 
                                        'text' => $1,
                                        'parent' => $current };
    }

    while (1) {
      # in a raw or ignored conditional block command
      if ($current->{'cmdname'} and 
            $block_commands{$current->{'cmdname'}} and 
            ($block_commands{$current->{'cmdname'}} eq 'raw'
             or $block_commands{$current->{'cmdname'}} eq 'conditional')) {
        # r?macro may be nested
        if (($current->{'cmdname'} eq 'macro' 
              or $current->{'cmdname'} eq 'rmacro') 
             and $line =~ /^\s*\@r?macro\s+/) {
          $line =~ s/\s*\@(r?macro)//;
          push @{$current->{'contents'}}, { 'cmdname' => $1,
                                            'parent' => $current,
                                            'contents' => [],
                         'extra' => {'arg_line' => $line }};
          $current = $current->{'contents'}->[-1];
          last;
        # ifclear/ifset may be nested
        } elsif (($current->{'cmdname'} eq 'ifclear' 
                  or $current->{'cmdname'} eq 'ifset'
                  or $current->{'cmdname'} eq 'ifcommanddefined'
                  or $current->{'cmdname'} eq 'ifcommandnotdefined')
                and $line =~ /^\s*\@$current->{'cmdname'}/) {
          $line =~ s/\s*\@($current->{'cmdname'})//;
          push @{$current->{'contents'}}, { 'cmdname' => $1,
                                            'parent' => $current,
                                            'contents' => [],
                         'extra' => {'line' => $line }};
          $current = $current->{'contents'}->[-1];
          last;
        } elsif ($line =~ /^(\s*?)\@end\s+([a-zA-Z][\w-]*)/
                 and ($2 eq $current->{'cmdname'})) {
          my $end_command = $2;
          $line =~ s/^(\s*?)(\@end\s+$current->{'cmdname'})//;
          if ($1 eq '') {
            # FIXME exclude other formats, like @macro, @ifset, @ignore?
            if ($current->{'cmdname'} ne 'verbatim'
                and @{$current->{'contents'}}
                and $current->{'contents'}->[-1]->{'type'}
                and $current->{'contents'}->[-1]->{'type'} eq 'raw') {
              if ($current->{'contents'}->[-1]->{'text'} =~ s/(\n)//) {
                push @{$current->{'contents'}}, {'type' => 'last_raw_newline',
                                          'text' => $1, 'parent' => $current};
              }
            }
          } else {
            push @{$current->{'contents'}}, 
              { 'text' => $1, 'type' => 'raw', 'parent' => $current };
            $self->line_warn(sprintf(__("\@end %s should only appear at the beginning of a line"), 
                                     $end_command), $line_nr);
          }
          # if there is a user defined macro that expandes to spaces, there
          # will be a spurious warning.
          $self->line_warn(sprintf(
                __("superfluous argument to \@%s %s: %s"), 'end', $end_command,
                                    $line), $line_nr)
            if ($line =~ /\S/ and $line !~ /^\s*\@c(omment)?\b/);
          # store toplevel macro specification
          if (($end_command eq 'macro' or $end_command eq 'rmacro') 
               and (! $current->{'parent'} 
                    or !$current->{'parent'}->{'cmdname'} 
                    or ($current->{'parent'}->{'cmdname'} ne 'macro'
                        and $current->{'parent'}->{'cmdname'} ne 'rmacro'))) {
            my $macrobody =
               Texinfo::Convert::Texinfo::convert({ 'contents' 
                                             => $current->{'contents'} });
            if ($current->{'args'} and $current->{'args'}->[0]) {
              my $name = $current->{'args'}->[0]->{'text'};
              if (exists($self->{'macros'}->{$name})) {
                $self->line_warn(sprintf(__("macro `%s' previously defined"), 
                                          $name), $current->{'line_nr'});
                $self->line_warn(sprintf(__(
                                   "here is the previous definition of `%s'"), 
               $name), $self->{'macros'}->{$name}->{'element'}->{'line_nr'});
              }
              if ($all_commands{$name}) {
                $self->line_warn(sprintf(__(
                                  "redefining Texinfo language command: \@%s"), 
                                          $name), $current->{'line_nr'});
              }
              if (!$current->{'extra'}->{'invalid_syntax'}) {
                $self->{'macros'}->{$name} = {
                  'element' => $current,
                  'macrobody' => $macrobody
                };
                # Don't need 'args_index' in final tree.
                if (defined $current->{'extra'}->{'args_index'}) {
                  $self->{'macros'}->{$name}->{'args_index'}
                                       = $current->{'extra'}->{'args_index'};
                  delete $current->{'extra'}->{'args_index'};
                }
              } elsif (defined $current->{'extra'}->{'args_index'}) {
                delete $current->{'extra'}->{'args_index'};
              }
            }
          }
          $current = $current->{'parent'};
          if ($block_commands{$end_command} eq 'conditional') {
            # don't store ignored @if*
            my $conditional = pop @{$current->{'contents'}};
            if (!defined($conditional->{'cmdname'}
                or $conditional->{'cmdname'} ne $end_command)) {
              $self->_bug_message("Ignored command is not the conditional $end_command", 
                                   $line_nr, $conditional);
              die;
            }
            # Ignore until end of line
            if ($line !~ /\n/) {
              ($line, $line_nr) = _new_line($self, $line_nr);
              print STDERR "IGNORE CLOSE line: $line" if ($self->{'DEBUG'});
            }
            print STDERR "CLOSED conditional $end_command\n" if ($self->{'DEBUG'});
            last;
          } else {
            print STDERR "CLOSED raw $end_command\n" if ($self->{'DEBUG'});
            $line =~ s/^([^\S\r\n]*)//;
            # Start an element to have the spaces at the end of the line
            # ignored.
            push @{$current->{'contents'}},
                        { 'type' => 'empty_line_after_command',
                          'text' => $1,
                          'parent' => $current,
                        };
          }
        } else {
          if (@{$current->{'contents'}} 
              and $current->{'contents'}->[-1]->{'type'}
              and $current->{'contents'}->[-1]->{'type'} eq 'empty_line_after_command'
              and $current->{'contents'}->[-1]->{'text'} !~ /\n/
              and $line !~ /\S/) {
            $current->{'contents'}->[-1]->{'text'} .= $line;
          } else {
            push @{$current->{'contents'}}, 
              { 'text' => $line, 'type' => 'raw', 'parent' => $current };
          }
          last;
        }
      # in @verb. type should be 'brace_command_arg'
      } elsif ($current->{'parent'} and $current->{'parent'}->{'cmdname'}
             and $current->{'parent'}->{'cmdname'} eq 'verb') {
        # collect the first character if not already done
        if (!defined($current->{'parent'}->{'extra'}->{'delimiter'})) {
          if ($line =~ /^$/) {
            $current->{'parent'}->{'extra'}->{'delimiter'} = '';
            $self->line_error(sprintf(
                __("\@%s without associated character"), 'verb'), $line_nr);
          } else {
            $line =~ s/^(.)//;
            $current->{'parent'}->{'extra'}->{'delimiter'} = $1;
          }
        }
        my $char = quotemeta($current->{'parent'}->{'extra'}->{'delimiter'});
        if ($line =~ s/^(.*?)$char\}/\}/) {
          push @{$current->{'contents'}}, 
              { 'text' => $1, 'type' => 'raw', 'parent' => $current } 
                if ($1 ne '');
          print STDERR "END VERB\n" if ($self->{'DEBUG'});
        } else {
          push @{$current->{'contents'}}, 
             { 'text' => $line, 'type' => 'raw', 'parent' => $current };
          print STDERR "LINE VERB: $line" if ($self->{'DEBUG'});
          last;
        }
      }

      # this mostly happens in the following cases:
      #   after expansion of user defined macro that doesn't end with EOL
      #   after a protection of @\n in @def* line
      #   at the end of an expanded Texinfo fragment
      while ($line eq '') {
        print STDERR "EMPTY TEXT\n"
          if ($self->{'DEBUG'});
        ($line, $line_nr) = _next_text($self, $line_nr);
        if (!defined($line)) {
          # end of the file or of a text fragment.
          $current = _end_line ($self, $current, $line_nr);
          # It may happen that there is an @include file on the line, it 
          # will be picked up at NEXT_LINE, beginning a new line
          next NEXT_LINE;
        }
      }

      # handle user defined macros before anything else since
      # their expansion may lead to changes in the line
      # REMACRO
      my $at_command_length;
      
      my ($at_command, $open_brace, $asterisk, $single_letter_command,
        $separator_match, $misc_text) = _parse_texi_regex ($line);

      if ($at_command) {
        $at_command_length = length($at_command) + 1;
      }
      if ($at_command
            and ($self->{'macros'}->{$at_command} 
                 or (exists $self->{'aliases'}->{$at_command} and 
                   $self->{'macros'}->{$self->{'aliases'}->{$at_command}}))) {
        substr($line, 0, $at_command_length) = '';
        my $command = $at_command;
        my $alias_command;
        if (exists($self->{'aliases'}->{$command})) {
          $alias_command = $command;
          $command = $self->{'aliases'}->{$command};
        }

        my $expanded_macro = $self->{'macros'}->{$command}->{'element'};
        my $args_number = scalar(@{$expanded_macro->{'args'}}) -1;
        my $arguments = [];
        if ($line =~ s/^\s*{\s*//) { # macro with args
          ($arguments, $line, $line_nr) = 
            _expand_macro_arguments($self, $expanded_macro, $line, $line_nr);
        } elsif (($args_number >= 2) or ($args_number <1)) {
        # as agreed on the bug-texinfo mailing list, no warn when zero
        # arg and not called with {}.
          $self->line_warn(sprintf(__(
   "\@%s defined with zero or more than one argument should be invoked with {}"), 
                                    $command), $line_nr)
             if ($args_number >= 2);
        } else {
          if ($line !~ /\n/) {
            ($line, $line_nr) = _new_line($self, $line_nr);
            $line = '' if (!defined($line));
          }
          $line =~ s/^\s*// if ($line =~ /\S/);
          my $has_end_of_line = chomp $line;
          $arguments = [$line];
          $line = "\n" if ($has_end_of_line);
        }
        my $expanded = _expand_macro_body ($self,
                                   $self->{'macros'}->{$command},
                                   $arguments, $line_nr);
        print STDERR "MACROBODY: $expanded".'||||||'."\n" 
           if ($self->{'DEBUG'}); 
        # empty result.  It is ignored here.
        if ($expanded eq '') {
          next;
        }
        if ($self->{'MAX_MACRO_CALL_NESTING'}
            and scalar(@{$self->{'macro_stack'}}) > $self->{'MAX_MACRO_CALL_NESTING'}) {
          $self->line_warn(sprintf(__(
"macro call nested too deeply (set MAX_NESTED_MACROS to override; current value %d)"), 
                                $self->{'MAX_MACRO_CALL_NESTING'}), $line_nr);
          next;
        }
        if ($expanded_macro->{'cmdname'} eq 'macro') {
          my $found = 0;
          foreach my $macro (@{$self->{'macro_stack'}}) {
            if ($macro->{'args'}->[0]->{'text'} eq $command) {
              $self->line_error(sprintf(__(
             "recursive call of macro %s is not allowed; use \@rmacro if needed"),
                                         $command), $line_nr);
              $found = 1;
              last;
            }
          }
          next if ($found);
        }

        my $expanded_lines = _text_to_lines($expanded);
        next if (!@$expanded_lines);
        chomp ($expanded_lines->[-1]);
        pop @$expanded_lines if ($expanded_lines->[-1] eq '');
        print STDERR "MACRO EXPANSION LINES: ".join('|', @$expanded_lines)
                                     ."|\nEND LINES MACRO EXPANSION\n" if ($self->{'DEBUG'});
        next if (!@$expanded_lines);
        unshift @{$self->{'macro_stack'}}, $expanded_macro;
        print STDERR "UNSHIFT MACRO_STACK: $expanded_macro->{'args'}->[0]->{'text'}\n"
          if ($self->{'DEBUG'});
        my $new_lines = _complete_line_nr($expanded_lines, 
                            $line_nr->{'line_nr'}, $line_nr->{'file_name'},
                            $expanded_macro->{'args'}->[0]->{'text'}, 1);
        $line_nr->{'end_macro'} = 1;
        unshift @{$self->{'input'}->[0]->{'pending'}}, [$line, $line_nr];
        my $new_text = shift @$new_lines;
        ($line, $line_nr) = ($new_text->[0], $new_text->[1]);
        unshift @{$self->{'input'}->[0]->{'pending'}}, @$new_lines;

      # Now handle all the cases that may lead to command closing
      # or following character association with an @-command, especially
      # accent command, that is handle @-command with braces that don't
      # always need a brace.

      # The condition below is only caught right after command opening,
      # otherwise we are in the 'args' and not right in the command container.
      } elsif ($current->{'cmdname'}
            and defined($brace_commands{$current->{'cmdname'}})
            and !$open_brace) {
        # special case for @-command as argument of @itemize or @*table.
        if (_command_with_command_as_argument($current->{'parent'})) {
          print STDERR "FOR PARENT \@$current->{'parent'}->{'parent'}->{'cmdname'} command_as_argument $current->{'cmdname'}\n" if ($self->{'DEBUG'});
          $current->{'type'} = 'command_as_argument' if (!$current->{'type'});
          $current->{'parent'}->{'parent'}->{'extra'}->{'command_as_argument'} 
            = $current;
          $current = $current->{'parent'};
        # now accent commands
        } elsif ($accent_commands{$current->{'cmdname'}}) {
          if ($line =~ /^[^\S\r\n]/) {
            if ($current->{'cmdname'} =~ /^[a-zA-Z]/) {
              $line =~ s/^([^\S\r\n]+)//;
              $current->{'extra'}->{'spaces'} = '' 
                if (!defined($current->{'extra'}->{'spaces'}));
              $current->{'extra'}->{'spaces'} .= $1;
            } else {
              $self->line_warn(sprintf(
                __("accent command `\@%s' must not be followed by whitespace"),
                $current->{'cmdname'}), $line_nr);
              $current = $current->{'parent'};
            }
          } elsif ($line =~ /^\@/) {
            $self->line_error(sprintf(
              __("use braces to give a command as an argument to \@%s"),
                $current->{'cmdname'}), $line_nr);
            $current = $current->{'parent'};
          } elsif ($line =~ s/^(.)//o) {
            print STDERR "ACCENT \@$current->{'cmdname'}\n" 
              if ($self->{'DEBUG'});
            my $following_arg = {'type' => 'following_arg',
                                 'parent' => $current};
            $following_arg->{'contents'} = [{ 'text' => $1,
                                             'parent' => $following_arg } ];
            $current->{'args'} = [ $following_arg ];
            if ($current->{'cmdname'} eq 'dotless' and $1 ne 'i' and $1 ne 'j') {
              $self->line_error(sprintf(
                 __("%c%s expects `i' or `j' as argument, not `%s'"), 
                 ord('@'), $current->{'cmdname'}, $1), $line_nr);
            }
            if ($current->{'cmdname'} =~ /^[a-zA-Z]/) {
              $current->{'args'}->[-1]->{'type'} = 'space_command_arg';
            }
            $current = $current->{'parent'};
          } else { # The accent is at end of line
            # whitespace for commands with letter.
            print STDERR "STRANGE ACC \@$current->{'cmdname'}\n" if ($self->{'DEBUG'});
            $self->line_warn(sprintf(
               __("accent command `\@%s' must not be followed by new line"),
               $current->{'cmdname'}), $line_nr);
            $current = $current->{'parent'};
          }
          next;
        } else {
          # ignore space after a braced @-command like TeX does
          if ($self->{'IGNORE_SPACE_AFTER_BRACED_COMMAND_NAME'}
              and $line =~ s/^\s+//) {
            next;
          }
          $self->line_error(sprintf(__("\@%s expected braces"), 
                           $current->{'cmdname'}), $line_nr);
          $current = $current->{'parent'};
        }
      # maybe a menu entry beginning: a * at the beginning of a menu line
      } elsif ($current->{'type'}
                and $current->{'type'} eq 'preformatted'
                and $current->{'parent'}->{'type'} 
                and ($current->{'parent'}->{'type'} eq 'menu_comment'
                     or $current->{'parent'}->{'type'} eq 'menu_entry_description')
                and $asterisk
                and @{$current->{'contents'}} 
                and $current->{'contents'}->[-1]->{'type'}
                and $current->{'contents'}->[-1]->{'type'} eq 'empty_line'
                and $current->{'contents'}->[-1]->{'text'} eq '') {
        print STDERR "MENU STAR\n" if ($self->{'DEBUG'});
        _abort_empty_line($self, $current);
        $line =~ s/^\*//;
        push @{$current->{'contents'}}, { 'parent' => $current,
                                          'type' => 'menu_star',
                                          'text' => '*' };
      # a space after a * at the beginning of a menu line
      } elsif ($current->{'contents'} and @{$current->{'contents'}} 
               and $current->{'contents'}->[-1]->{'type'}
               and $current->{'contents'}->[-1]->{'type'} eq 'menu_star') {
        if ($line !~ /^\s+/) {
          print STDERR "ABORT MENU STAR ($line)\n" if ($self->{'DEBUG'});
          delete $current->{'contents'}->[-1]->{'type'};
        } else {
          print STDERR "MENU ENTRY (certainly)\n" if ($self->{'DEBUG'});
          # this is the menu star collected previously
          pop @{$current->{'contents'}};
          $line =~ s/^(\s+)//;
          my $leading_text = '*' . $1;
          if ($current->{'type'} eq 'preformatted'
              and $current->{'parent'}->{'type'} 
              and $current->{'parent'}->{'type'} eq 'menu_comment') {
            my $menu = $current->{'parent'}->{'parent'};
            if (!@{$current->{'contents'}}) {
              pop @{$current->{'parent'}->{'contents'}};
              if (!scalar(@{$current->{'parent'}->{'contents'}})) {
                pop @{$menu->{'contents'}}; 
              }
            }
            $current = $menu;
          } else {
            # first parent preformatted, third is menu_entry
            if ($current->{'type'} ne 'preformatted' 
                or $current->{'parent'}->{'type'} ne 'menu_entry_description'
                or $current->{'parent'}->{'parent'}->{'type'} ne 'menu_entry'
                or !$menu_commands{$current->{'parent'}->{'parent'}->{'parent'}->{'cmdname'}}) {
              $self->_bug_message("Not in menu comment nor description", 
                                   $line_nr, $current);
            }
            $current = $current->{'parent'}->{'parent'}->{'parent'};
          }
          my $context = pop @{$self->{'context_stack'}};
          if ($context ne 'preformatted') {
            $self->_bug_message("context $context instead of preformatted after menu leading star", 
                                $line_nr, $current);
          }
          push @{$current->{'contents'}}, { 'type' => 'menu_entry',
                                            'parent' => $current,
                                          };
          $current = $current->{'contents'}->[-1];
          $current->{'args'} = [ { 'type' => 'menu_entry_leading_text',
                                   'text' => $leading_text,
                                   'parent' => $current },
                                 { 'type' => 'menu_entry_name',
                                   'contents' => [],
                                   'parent' => $current } ];
          $current = $current->{'args'}->[-1];
        }
      # after a separator in menu
      } elsif ($current->{'args'} and @{$current->{'args'}} 
               and $current->{'args'}->[-1]->{'type'}
               and $current->{'args'}->[-1]->{'type'} eq 'menu_entry_separator') {
        my $separator = $current->{'args'}->[-1]->{'text'};
        # separator is ::, we concatenate and let the while restart
        # in order to collect spaces below
        if ($separator eq ':' and $line =~ s/^(:)//) {
          $current->{'args'}->[-1]->{'text'} .= $1;
        # a . not followed by a space.  Not a separator.
        } elsif ($separator eq '.' and $line =~ /^\S/) {
          pop @{$current->{'args'}};
          $current = $current->{'args'}->[-1];
          $current = _merge_text($self, $current, $separator);
        # here we collect spaces following separators.
        } elsif ($line =~ s/^([^\S\r\n]+)//) {
          # FIXME a trailing end of line could be considered to be part
          # of the separator. Right now it is part of the description,
          # since it is catched (in the next while) as one of the case below
          $current->{'args'}->[-1]->{'text'} .= $1;
        # now handle the menu part that was closed
        } elsif ($separator =~ /^::/) {
          print STDERR "MENU NODE no entry $separator\n" if ($self->{'DEBUG'});
          # it was previously registered as menu_entry_name, it is 
          # changed to node
          $current->{'args'}->[-2]->{'type'} = 'menu_entry_node';
          $current = _enter_menu_entry_node($self, $current, $line_nr);
        # end of the menu entry name  
        } elsif ($separator =~ /^:/) {
          print STDERR "MENU ENTRY $separator\n" if ($self->{'DEBUG'});
          push @{$current->{'args'}}, { 'type' => 'menu_entry_node',
                                        'contents' => [],
                                        'parent' => $current };
          $current = $current->{'args'}->[-1];
        # anything else is the end of the menu node following a menu_entry_name
        } else {
          print STDERR "MENU NODE $separator\n" if ($self->{'DEBUG'});
          $current = _enter_menu_entry_node($self, $current, $line_nr);
        }
        # REMACRO
      } elsif ($at_command or $single_letter_command) {
        my $command;
        if (!$at_command) {
          $command = $single_letter_command;
          substr($line, 0, 2) = '';
        } else {
          $command = $at_command;
          substr($line, 0, $at_command_length) = '';
        }

        print STDERR "COMMAND $command\n" if ($self->{'DEBUG'});
        if (!$all_commands{$command}
            and !$self->{'macros'}->{$command}
            and !$self->{'definfoenclose'}->{$command}
            and !$self->{'aliases'}->{$command}
            and !$self->{'command_index'}->{$command}) {
          $self->line_error(sprintf(__("unknown command `%s'"), 
                                      $command), $line_nr);
          _abort_empty_line($self, $current);
          my $paragraph = _begin_paragraph($self, $current, $line_nr);
          $current = $paragraph if ($paragraph);
          next;
        }

        my $alias_command;
        if (exists($self->{'aliases'}->{$command})) {
          $alias_command = $command;
          $command = $self->{'aliases'}->{$command};
        }

        if ($command eq 'value') {
          $line =~ s/^\s*// 
             if ($self->{'IGNORE_SPACE_AFTER_BRACED_COMMAND_NAME'});
          # REVALUE
          if ($line =~ s/^{([\w\-][^\s{\\}~`\^+"<>|@]*)}//) {
            my $value = $1;
            if (exists($self->{'values'}->{$value})) {
              if (!defined($self->{'values'}->{$value})) {
                print STDERR "BUG? $value exists but not defined\n";
              } elsif (!ref($self->{'values'}->{$value})) {
                $line = $self->{'values'}->{$value} . $line;
              } else {
                print STDERR "BUG? $value defined as reference\n";
              }
            } else {
              # Flag not defined.  This is an error if it comes from
              # a user's document.  It is also expected behaviour for
              # Texinfo::Report::gdt, where we want to defer substitution
              # of the value until after the containing Texinfo is parsed.
              _abort_empty_line($self, $current);
              # caller should expand something along 
              # gdt('@{No value for `{value}\'@}', {'value' => $value}, {'keep_texi'=> 1});
              push @{$current->{'contents'}}, { 'cmdname' => 'value',
                                                'type' => $value,
                                                'contents' => [],
                                                'parent' => $current };
              if (!$self->{'in_gdt'}) {
                $self->line_warn(
                   sprintf(__("undefined flag: %s"), $value), $line_nr);
              }
            }
          } else {
            $self->line_error(__("bad syntax for \@value"), $line_nr);
          }
          next;
        }

        if (defined($deprecated_commands{$command})) {
          if ($deprecated_commands{$command} eq '') {
            $self->line_warn(sprintf(__("%c%s is obsolete."), 
                                ord('@'), $command), $line_nr);
          } else {
            $self->line_warn(sprintf(__("%c%s is obsolete; %s"),
                   ord('@'), $command, 
                   __($deprecated_commands{$command})), $line_nr);
          }
        }

        # special case with @ followed by a newline protecting end of lines
        # in @def*
        my $def_line_continuation
          = ($self->{'context_stack'}->[-1] eq 'def' and $command eq "\n");

        if (not $def_line_continuation
               and not _abort_empty_line($self, $current) 
               and $begin_line_commands{$command}) {
          $self->line_warn( 
              sprintf(__("\@%s should only appear at the beginning of a line"), 
                      $command), $line_nr);
        }

        _check_valid_nesting ($self, $current, $command, $line_nr);

        last if ($def_line_continuation);

        unless ($self->{'no_paragraph_commands'}->{$command}) {
          my $paragraph = _begin_paragraph($self, $current, $line_nr);
          $current = $paragraph if ($paragraph);
        }

        if ($self->{'close_paragraph_commands'}->{$command}) {
          $current = _end_paragraph($self, $current, $line_nr);
        }
        if ($self->{'close_preformatted_commands'}->{$command}) {
          $current = _end_preformatted($self, $current, $line_nr);
        }

        if ($in_index_commands{$command}
            and $current->{'contents'}
            and $current->{'contents'}->[-1]
            and $current->{'contents'}->[-1]->{'text'}) {
          $current->{'contents'}->[-1]->{'text'} =~ s/(\s+)$//;
          if ($1 ne '') {
            my $new_spaces = { 'text' => $1, 'parent' => $current,
              'type' => 'empty_spaces_before_argument' };
            push @{$current->{'contents'}}, $new_spaces;
          }
        }

        if (defined($other_commands{$command})
            and ($command ne 'item' or !_item_line_parent($current))) {
          # noarg skipspace
          my $arg_spec = $other_commands{$command};
          my $misc;

          if ($arg_spec eq 'noarg') {
            if ($in_heading_commands{$command}) {
              $self->line_error(
                sprintf(__("\@%s should only appear in heading or footing"),
                        $command), $line_nr);
            }
            $misc = {'cmdname' => $command, 'parent' => $current};
            push @{$current->{'contents'}}, $misc;
            _register_global_command($self, $misc, $line_nr);
            $current = _begin_preformatted($self, $current)
              if ($close_preformatted_commands{$command});
          } else {
            if ($command eq 'item'
                or $command eq 'headitem' or $command eq 'tab') {
              my $parent;
              # @itemize or @enumerate
              if ($parent = _item_container_parent($current)) {
                if ($command eq 'item') {
                  print STDERR "ITEM_CONTAINER\n" if ($self->{'DEBUG'});
                  $parent->{'items_count'}++;
                  $misc = { 'cmdname' => $command, 'parent' => $parent,
                            'contents' => [],
                            'extra' => 
                              {'item_number' => $parent->{'items_count'}} };
                  push @{$parent->{'contents'}}, $misc;
                  $current = $parent->{'contents'}->[-1];
                } else {
                  $self->line_error(sprintf(__(
                                "\@%s not meaningful inside `\@%s' block"), 
                                   $command, $parent->{'cmdname'}), $line_nr);
                }
                $current = _begin_preformatted($self, $current);
              # @*table
              } elsif ($parent = _item_line_parent($current)) {
                $self->line_error(sprintf(__(
                      "\@%s not meaningful inside `\@%s' block"), 
                    $command, $parent->{'cmdname'}), $line_nr);
                $current = _begin_preformatted($self, $current);
              # @multitable
              } elsif ($parent = _item_multitable_parent($current)) {
                if ($command eq 'item' or $command eq 'headitem'
                     or $command eq 'tab') {
                  if (!$parent->{'extra'}->{'max_columns'}) {
                    $self->line_warn(
                       sprintf(__("\@%s in empty multitable"), 
                               $command), $line_nr);
                  } elsif ($command eq 'tab') {
                    my $row = $parent->{'contents'}->[-1];
                    die if (!$row->{'type'});
                    if ($row->{'type'} eq 'before_item') {
                      $self->line_error(__("\@tab before \@item"), $line_nr);
                    } elsif ($row->{'cells_count'} >= $parent->{'extra'}->{'max_columns'}) {
                      $self->line_error(sprintf(__(
                              "too many columns in multitable item (max %d)"), 
                             $parent->{'extra'}->{'max_columns'}), $line_nr);
                    } else {
                      $row->{'cells_count'}++;
                      $misc = { 'cmdname' => $command,
                                'parent' => $row,
                                'contents' => [],
                                'extra' =>
                            {'cell_number' => $row->{'cells_count'}} };
                      push @{$row->{'contents'}}, $misc;
                      $current = $row->{'contents'}->[-1];
                      #$current = $self->_begin_preformatted($current);
                      print STDERR "TAB\n" if ($self->{'DEBUG'});
                    }
                  } else {
                    print STDERR "ROW\n" if ($self->{'DEBUG'});
                    $parent->{'rows_count'}++;
                    my $row = { 'type' => 'row', 'contents' => [],
                                'cells_count' => 1,
                                'extra' => {'row_number' => $parent->{'rows_count'} },
                                'parent' => $parent };
                    push @{$parent->{'contents'}}, $row;
                    $misc =  { 'cmdname' => $command,
                               'parent' => $row,
                               'contents' => [],
                               'extra' => {'cell_number' => 1}};
                    push @{$row->{'contents'}}, $misc;
                    $current = $row->{'contents'}->[-1];
                  }
                } else {
                  $self->line_error(sprintf(__(
                           "\@%s not meaningful inside `\@%s' block"), 
                               $command, $parent->{'cmdname'}), $line_nr);
                }
                $current = _begin_preformatted($self, $current);
              } elsif ($command eq 'tab') {
                $self->line_error(__(
                           "ignoring \@tab outside of multitable"), $line_nr);
                $current = _begin_preformatted($self, $current);
              } else {
                $self->line_error (sprintf(__(
                   "\@%s outside of table or list"), $command), $line_nr);
                $current = _begin_preformatted($self, $current);
              }
              $misc->{'line_nr'} = $line_nr if (defined($misc));
            } else {
              $misc = { 'cmdname' => $command, 'parent' => $current,
                  'line_nr' => $line_nr };
              push @{$current->{'contents'}}, $misc;
            }
            $line = _start_empty_line_after_command($line, $current, $misc);
            if ($command eq 'indent'
                or $command eq 'noindent') {
              if ($line !~ /\n/) {
                my ($new_line, $new_line_nr) = _new_line($self, $line_nr);
                $line .= $new_line if (defined($new_line));
              }
              $line =~ s/^(\s*)//;
              if ($1) {
                $current = _merge_text($self, $current, $1);
              }
              if ($line ne ''
                  and $current->{'contents'}->[-1]->{'type'} eq
                'empty_line_after_command') {
                $current->{'contents'}->[-1]->{'type'}
                = 'empty_spaces_after_command';
              }
              my $paragraph = _begin_paragraph($self, $current, $line_nr);
              $current = $paragraph if $paragraph;
              if ($line eq '') {
                last;
              }
            }
          }
        # line commands
        } elsif (defined($self->{'line_commands'}->{$command})) {
          if ($root_commands{$command} or $command eq 'bye') {
            $current = _close_commands($self, $current, $line_nr, undef, 
                                       $command);
            # root_level commands leads to setting a new root
            # for the whole document and stuffing the preceding text
            # as the first content, this is done only once.
            if ($current->{'type'} and $current->{'type'} eq 'text_root') {
              if ($command ne 'bye') {
                $root = { 'type' => 'document_root', 'contents' => [$current] };
                $current->{'parent'} = $root;
                $current = $root;
              }
            } else {
              die if (!defined($current->{'parent'}));
              $current = $current->{'parent'};
            }
          }

          # skipline text line lineraw /^\d$/
          my $arg_spec = $self->{'line_commands'}->{$command};
          my $misc;

          # all the cases using the raw line
          if ($arg_spec eq 'skipline' or $arg_spec eq 'lineraw'
                   or $arg_spec eq 'special') {
            my $ignored = 0;
            if ($command eq 'insertcopying') {
              my $parent = $current;
              while ($parent) {
                if ($parent->{'cmdname'} and $parent->{'cmdname'} eq 'copying') {
                  $self->line_error(
                     sprintf(__("\@%s not allowed inside `\@%s' block"), 
                             $command, $parent->{'cmdname'}), $line_nr);
                  $ignored = 1;
                  last;
                }
                $parent = $parent->{'parent'};
              }
            } 

            # complete the line if there was a user macro expansion
            if ($line !~ /\n/) {
              my ($new_line, $new_line_nr) = _new_line($self, $line_nr);
              $line .= $new_line if (defined($new_line));
            }
            $misc = {'cmdname' => $command,
                     'parent' => $current};
            my $args = [];
            my $has_comment;
            if ($arg_spec eq 'lineraw' or $arg_spec eq 'skipline') {
              $args = [ $line ];
            } elsif ($arg_spec eq 'special') {
              ($args, $has_comment) 
               = _parse_special_misc_command($self, $line, $command, $line_nr);
              $misc->{'extra'}->{'arg_line'} = $line;
            }

            # if using the @set txi* instead of a proper @-command, replace
            # by the tree obtained with the @-command.  Even though
            # _end_line is called below, as $current is not line_arg
            # there should not be anything done in addition than what is
            # done for @clear or @set.
            if (($command eq 'set' or $command eq 'clear')
                 and scalar(@$args) >= 1
                 and $set_flag_command_equivalent{$args->[0]}) {
              my $arg; 
              if ($command eq 'set') {
                $arg = 'on';
              } else {
                $arg = 'off';
              }
              $command = $set_flag_command_equivalent{$args->[0]};
              $misc = {'cmdname' => $command,
                       'parent' => $current,
                       'line_nr' => $line_nr,
                       'extra' => {'misc_args' => [$arg]}};
              my $misc_line_args = {'type' => 'line_arg',
                     'parent' => $misc};
              $misc->{'args'} = [$misc_line_args];
              $misc->{'extra'}->{'spaces_before_argument'} = ' ';
              $misc_line_args->{'contents'} = [
                { 'text' => $arg,
                  'parent' => $misc_line_args, },
                { 'text' => "\n",
                  'parent' => $misc_line_args,
                  'type' => 'spaces_at_end', } ];
              push @{$current->{'contents'}}, $misc;
            } else {
              if (!$ignored) {
                push @{$current->{'contents'}}, $misc;
                foreach my $arg (@$args) {
                  push @{$misc->{'args'}},
                    { 'type' => 'misc_arg', 'text' => $arg, 
                      'parent' => $current->{'contents'}->[-1] };
                }
                $misc->{'extra'}->{'misc_args'} = $args 
                  if (scalar(@$args) and $arg_spec ne 'skipline');
              } else {
                $misc = undef;
              }
            }
            if ($command eq 'raisesections') {
              $self->{'sections_level'}++;
            } elsif ($command eq 'lowersections') {
              $self->{'sections_level'}--;
            } elsif ($command eq 'novalidate') {
              $self->{'info'}->{'novalidate'} = 1;
            }
            _register_global_command($self, $misc, $line_nr)
              if $misc;
            # the end of line is ignored for special commands
            if ($arg_spec ne 'special' or !$has_comment) {
              $current = _end_line($self, $current, $line_nr);
            }

            last NEXT_LINE if ($command eq 'bye');
            # Even if _end_line is called, it is not done since there is 
            # no line_arg
            $current = _begin_preformatted($self, $current)
              if ($close_preformatted_commands{$command});
            last;
          } else {
            # $arg_spec is text, line or a number
            # @item or @itemx in @table
            if ($command eq 'item' or $command eq 'itemx') {
              my $parent;
              print STDERR "ITEM_LINE\n" if ($self->{'DEBUG'});
              if ($parent = _item_line_parent($current)) {
                $current = $parent;
                _gather_previous_item($self, $current, $command, $line_nr);
              } else {
                $self->line_error (sprintf(__(
                   "\@%s outside of table or list"), $command), $line_nr);
                $current = _begin_preformatted($self, $current);
              }
              $misc = { 'cmdname' => $command, 'parent' => $current };
              push @{$current->{'contents'}}, $misc;
              $misc->{'line_nr'} = $line_nr;
            } else {
              $misc = { 'cmdname' => $command, 'line_nr' => $line_nr };
              if ($command eq 'subentry') {
                my $parent = $current->{'parent'};
                if (!_is_index_element($self, $parent)) {
                  $self->line_warn(
                    sprintf(__("\@%s should only appear in an index entry"),
                            $command), $line_nr);
                }
                $parent->{'extra'}->{'subentry'} = $misc;
                my $subentry_level = 1;
                if ($parent->{'cmdname'} eq 'subentry') {
                  $subentry_level = $parent->{'extra'}->{'level'} + 1;
                }
                $misc->{'extra'}->{'level'} = $subentry_level;
                if ($subentry_level > 2) {
                  $self->line_error(__(
              "no more than two levels of index subentry are allowed"),
                           $line_nr);
                }
                # Do not make the @subentry element a child of the index
                # command.  This means that spaces are preserved properly
                # when converting back to Texinfo.
                $current = _end_line($self, $current, $line_nr);
              }
              push @{$current->{'contents'}}, $misc;
              $misc->{'parent'} = $current;
              if ($sectioning_commands{$command}) {
                if ($self->{'sections_level'}) {
                  $current->{'contents'}->[-1]->{'extra'}->{'sections_level'}
                    = $self->{'sections_level'};
                }
              }
              if ($root_commands{$command}) {
                $misc->{'contents'} = [];
              }
              # def*x
              if ($def_commands{$command}) {
                my $base_command = $command;
                $base_command =~ s/x$//;
                # check that the def*x is first after @def*, no paragraph
                # in-between.
                my $after_paragraph = _check_no_text($current);
                push @{$self->{'context_stack'}}, 'def';
                $current->{'contents'}->[-1]->{'type'} = 'def_line';
                $current->{'contents'}->[-1]->{'extra'} = 
                   {'def_command' => $base_command,
                    'original_def_cmdname' => $command};
                if ($current->{'cmdname'} 
                    and $current->{'cmdname'} eq $base_command) {
                  pop @{$current->{'contents'}};
                  _gather_def_item($current, $command);
                  push @{$current->{'contents'}}, $misc; 
                }
                if (!$current->{'cmdname'} 
                     or $current->{'cmdname'} ne $base_command
                     or $after_paragraph) {
                  $self->line_error(sprintf(__(
                                       "must be after `\@%s' to use `\@%s'"), 
                                          $base_command, $command), $line_nr);
                  $current->{'contents'}->[-1]->{'extra'}->{'not_after_command'} = 1;
                }
              }
            }
            $current = $current->{'contents'}->[-1];
            $current->{'args'} = [{ 'type' => 'line_arg', 
                                    'contents' => [], 
                                    'parent' => $current }];
            # @node is the only misc command with args separated with comma
            # FIXME a 3 lingering here deep into the code may not
            # be very wise...  However having a hash only for one @-command
            # is not very appealing either...
            if ($command eq 'node') {
              $current->{'remaining_args'} = 3;
            } elsif ($command eq 'author') {
              my $parent = $current;
              my $found;
              while ($parent->{'parent'}) {
                $parent = $parent->{'parent'};
                last if ($parent->{'type'}
                        and $parent->{'type'} eq 'brace_command_context');
                if ($parent->{'cmdname'}) {
                  if ($parent->{'cmdname'} eq 'titlepage') {
                    $current->{'extra'}->{'titlepage'} = $parent;
                    $found = 1;
                  } elsif ($parent->{'cmdname'} eq 'quotation' or
                      $parent->{'cmdname'} eq 'smallquotation') {
                    push @{$parent->{'extra'}->{'authors'}}, $current;
                    $current->{'extra'}->{'quotation'} = $parent;
                    $found = 1;
                  }
                  last if ($found);
                }
              }
              if (!$found) {
                $self->line_warn(sprintf(__(
             "\@%s not meaningful outside `\@titlepage' and `\@quotation' environments"),
                               $command), $current->{'line_nr'});
              }
            } elsif ($command eq 'dircategory' and $self->{'current_node'}) {
                $self->line_warn(__("\@dircategory after first node"),
                             $line_nr);
            } elsif ($command eq 'printindex') {
              # Record that @printindex occurs in this node so we know it
              # is an index node.
              if ($self->{'current_node'}) {
                $self->{'current_node'}->{'extra'}->{'isindex'} = 1;
              }
            }

            $current = $current->{'args'}->[-1];
            push @{$self->{'context_stack'}}, 'line' 
              unless ($def_commands{$command});
            $line = _start_empty_line_after_command($line, $current, $misc);
          }
          _register_global_command($self, $misc, $line_nr)
            if $misc;
          if ($command eq 'dircategory') {
            push @{$self->{'info'}->{'dircategory_direntry'}}, $misc;
          }
        # @-command with matching @end opening
        } elsif (exists($block_commands{$command})) {
          if ($command eq 'macro' or $command eq 'rmacro') {
            my $macro = _parse_macro_command_line($self, $command, $line, 
                                                  $current, $line_nr);
            push @{$current->{'contents'}}, $macro;
            $current = $current->{'contents'}->[-1];
            last;
          } elsif ($block_commands{$command} eq 'conditional') {
            my $ifvalue_true = 0;
            if ($command eq 'ifclear' or $command eq 'ifset') {
              # REVALUE
              if ($line =~ /^\s+([\w\-][^\s{\\}~`\^+"<>|@]*)\s*(\@(c|comment)((\@|\s+).*)?)?$/) {
                my $name = $1;
                if ((exists($self->{'values'}->{$name}) and $command eq 'ifset')
                    or (!exists($self->{'values'}->{$name}) 
                         and $command eq 'ifclear')) {
                  $ifvalue_true = 1;
                }
                print STDERR "CONDITIONAL \@$command $name: $ifvalue_true\n" if ($self->{'DEBUG'});
              } elsif ($line !~ /\S/) {
                  $self->line_error(sprintf(
                    __("%c%s requires a name"), ord('@'), $command), $line_nr);
              } else {
                $self->line_error(sprintf(
                    __("bad name for \@%s"), $command), $line_nr);
              }
            } elsif ($command eq 'ifcommanddefined' 
                     or $command eq 'ifcommandnotdefined') {
              # REMACRO
              if ($line =~ /^\s+([[:alnum:]][[:alnum:]\-]*)\s*(\@(c|comment)((\@|\s+).*)?)?$/) {
                my $name = $1;
                my $command_is_defined = (
                  exists($Texinfo::Common::all_commands{$name})
                  or $self->{'macros'}->{$name}
                  or $self->{'definfoenclose'}->{$name}
                  or $self->{'aliases'}->{$name}
                  or $self->{'command_index'}->{$name}
                );
                if (($command_is_defined
                     and $command eq 'ifcommanddefined')
                    or (! $command_is_defined
                         and $command eq 'ifcommandnotdefined')) {
                  $ifvalue_true = 1;
                }
                print STDERR "CONDITIONAL \@$command $name: $ifvalue_true\n" if ($self->{'DEBUG'});
              } elsif ($line !~ /\S/) {
                  $self->line_error(sprintf(
                    __("%c%s requires a name"), ord('@'), $command), $line_nr);
              } else {
                $self->line_error(sprintf(
                    __("bad name for \@%s"), $command), $line_nr);
              }
            } elsif ($command =~ /^ifnot(.*)/) {
              $ifvalue_true = 1 if !($self->{'expanded_formats_hash'}->{$1}
                    # exception as explained in the texinfo manual
                    or ($1 eq 'info' 
                        and $self->{'expanded_formats_hash'}->{'plaintext'}));
              print STDERR "CONDITIONAL \@$command format $1: $ifvalue_true\n" if ($self->{'DEBUG'});
            } else {
              die unless ($command =~ /^if(.*)/);
              $ifvalue_true = 1 if ($self->{'expanded_formats_hash'}->{$1}
                      or ($1 eq 'info' 
                          and $self->{'expanded_formats_hash'}->{'plaintext'}));
              print STDERR "CONDITIONAL \@$command format $1: $ifvalue_true\n" if ($self->{'DEBUG'});
            }
            if ($ifvalue_true) {
              push @{$self->{'conditionals_stack'}}, $command;
            } else {
              push @{$current->{'contents'}}, { 'cmdname' => $command, 
                                                'parent' => $current,
                                                'contents' => [] };
              $current = $current->{'contents'}->[-1];
            }
            # FIXME(Karl) ignore what is remaining on the line, to eat 
            # the end of line?
            last;
          } else {
            my $block;
            # a menu command closes a menu_comment, but not the other
            # block commands. This won't catch menu commands buried in 
            # other formats (that are incorrect anyway).
            if ($menu_commands{$command} and $current->{'type'} 
                and ($current->{'type'} eq 'menu_comment' 
                     or $current->{'type'} eq 'menu_entry_description')) {

              my $menu;

              $menu = $current->{'parent'};
              pop @{$menu->{'contents'}}
                if (!@{$current->{'contents'}});

              my $context = pop @{$self->{'context_stack'}};
              if ($context ne 'preformatted') {
                $self->_bug_message("context $context instead of preformatted in new menu", 
                                   $line_nr, $current);
              }
              
              if ($menu->{'type'} and $menu->{'type'} eq 'menu_entry') {
                $menu = $menu->{'parent'};
              }

              $current = $menu;
            }
            # the def command holds a line_def* which corresponds with the
            # definition line.  This allows to have a treatement similar
            # with def*x.
            if ($def_commands{$command}) {
              push @{$self->{'context_stack'}}, 'def';
              $block = { 'parent' => $current,
                         'cmdname' => $command,
                         'contents' => [] };
              push @{$current->{'contents'}}, $block;
              $current = $current->{'contents'}->[-1];
              push @{$current->{'contents'}}, { 
                                                'type' => 'def_line',
                                                'parent' => $current,
                                                'line_nr' => $line_nr,
                                                'extra' => 
                                                 {'def_command' => $command,
                                                  'original_def_cmdname' => $command}
                                                };
            } else {
              $block = { 'cmdname' => $command,
                         'parent' => $current,
                         'contents' => [] };
              push @{$current->{'contents'}}, $block;
            }
            $current = $current->{'contents'}->[-1];

            if ($block_arg_commands{$command}) {
              if ($preformatted_commands{$command}) {
                push @{$self->{'context_stack'}}, 'preformatted';
              } elsif ($format_raw_commands{$command}) {
                push @{$self->{'context_stack'}}, 'rawpreformatted';
                if (not $self->{'expanded_formats_hash'}->{$command}) {
                  push @{$current->{'contents'}}, {
                    'parent' => $current,
                    'type' => 'elided_block',
                    'contents' => []
                  };
                  while (not $line =~ /^\s*\@end\s+$command/) {
                    ($line, $line_nr) = _new_line($self, $line_nr);
                    if (!$line) {
                      # unclosed block
                      $line = '';
                      last;
                    }
                  }
                  push @{$current->{'contents'}},
                                     { 'type' => 'empty_line_after_command', 
                                       'text' => "\n",
                                       'parent' => $current };
                  push @{$current->{'contents'}}, { 'type' => 'empty_line', 
                                                    'text' => '',
                                                    'parent' => $current };
                  next;
                }
              }
              if ($region_commands{$command}) {
                if (@{$self->{'regions_stack'}}) {
                  $self->line_error(
              sprintf(__("region %s inside region %s is not allowed"),
                      $command, $self->{'regions_stack'}->[-1]->{'cmdname'}), 
                                    $line_nr);
                }
                push @{$self->{'regions_stack'}}, $block;
              }
              if ($menu_commands{$command}) {
                if ($self->{'context_stack'}->[-1] eq 'preformatted') {
                  push @{$self->{'context_stack'}}, 'preformatted';
                } else {
                  push @{$self->{'context_stack'}}, 'menu';
                }
                push @{$self->{'info'}->{'dircategory_direntry'}}, $block
                  if ($command eq 'direntry');
                if ($self->{'current_node'}) {
                  if ($command eq 'direntry') {
                    if ($self->{'SHOW_MENU'}) {
                      $self->line_warn(__("\@direntry after first node"),
                                $line_nr);
                    }
                  } elsif ($command eq 'menu') {
                    if (!(defined $current->{'parent'}->{'cmdname'})
                        or $root_commands{$current->{'parent'}->{'cmdname'}}) {
                      push @{$self->{'current_node'}->{'menus'}}, $current;
                    } else {
                      $self->line_warn(__("\@menu in invalid context"), 
                                       $line_nr);
                    }
                  }
                } elsif ($command ne 'direntry') {
                  if ($self->{'SHOW_MENU'}) {
                    $self->line_error(sprintf(__("\@%s seen before first \@node"), 
                                              $command), $line_nr);
                    $self->line_error(__(
      "perhaps your \@top node should be wrapped in \@ifnottex rather than \@ifinfo?"), 
                                  $line_nr);
                  }
                }
              }
              $current->{'args'} = [ {
                 'type' => 'block_line_arg',
                 'contents' => [],
                 'parent' => $current } ];
              
              $current->{'remaining_args'} = $block_commands{$command} -1 
                if ($block_commands{$command} =~ /^\d+$/ 
                    and $block_commands{$command} -1 > 0);
              $current = $current->{'args'}->[-1];
              push @{$self->{'context_stack'}}, 'line' 
                unless ($def_commands{$command});
            }
            $block->{'line_nr'} = $line_nr;
            _register_global_command($self, $block, $line_nr);

            $line = _start_empty_line_after_command($line, $current, $block);
          }
        } elsif (defined($brace_commands{$command})) {
          push @{$current->{'contents'}}, { 'cmdname' => $command, 
                                            'parent' => $current,
                                            'contents' => [] };
          $current->{'contents'}->[-1]->{'line_nr'} = $line_nr
            if ($keep_line_nr_brace_commands{$command}
                and !$self->{'definfoenclose'}->{$command});
          if ($in_index_commands{$command}
              and !_is_index_element($self, $current->{'parent'})) {
            $self->line_warn(
              sprintf(__("\@%s should only appear in an index entry"),
                      $command), $line_nr);
          }
          
          $current = $current->{'contents'}->[-1];
          if ($command eq 'click') {
            $current->{'extra'}->{'clickstyle'} = $self->{'clickstyle'};
          } elsif ($command eq 'kbd') {
            if ($self->{'context_stack'}->[-1] eq 'preformatted'
                and $self->{'kbdinputstyle'} ne 'distinct') {
              $current->{'extra'}->{'code'} = 1;
            } elsif ($self->{'kbdinputstyle'} eq 'code'
                     or ($self->{'kbdinputstyle'} eq 'example'
                         and $self->_in_code($current->{'parent'}))) {
              $current->{'extra'}->{'code'} = 1;
            }
          }
          if ($self->{'definfoenclose'}->{$command}) {
            $current->{'type'} = 'definfoenclose_command';
            $current->{'extra'}->{'begin'} =
                 $self->{'definfoenclose'}->{$command}->[0]; 
            $current->{'extra'}->{'end'} =
                 $self->{'definfoenclose'}->{$command}->[1]; 
          }
        } elsif (exists ($no_brace_commands{$command})) {
          push @{$current->{'contents'}},
                 { 'cmdname' => $command, 'parent' => $current };
          # FIXME generalize?
          if ($command eq '\\' and $self->{'context_stack'}->[-1] ne 'math') {
            $self->line_warn(sprintf(__("\@%s should only appear in math context"), 
                                        $command), $line_nr);
          }
          if ($command eq "\n") {
            $current = _end_line($self, $current, $line_nr);
            last;
          }
        }
      } elsif ($separator_match) {
        my $separator = $separator_match;
        substr ($line, 0, 1) = '';
        print STDERR "SEPARATOR: $separator\n" if ($self->{'DEBUG'});
        if ($separator eq '@') {
          # this may happen with a @ at the very end of a file, therefore
          # not followed by anything.
          $self->line_error(__("unexpected \@"), $line_nr);
        } elsif ($separator eq '{') {
          _abort_empty_line($self, $current);
          if ($current->{'cmdname'} 
               and defined($brace_commands{$current->{'cmdname'}})) {
            my $command = $current->{'cmdname'};
            $current->{'args'} = [ { 'parent' => $current,
                                   'contents' => [] } ];

            if ($brace_commands{$command}
                and $brace_commands{$command} =~ /^\d$/
                and $brace_commands{$command} > 1) {
              $current->{'remaining_args'} = $brace_commands{$command} - 1;
            }

            $current = $current->{'args'}->[-1];
            if ($context_brace_commands{$command}) {
              if ($command eq 'caption' or $command eq 'shortcaption') {
                my $float;
                if (!$current->{'parent'}->{'parent'} 
                    or !$current->{'parent'}->{'parent'}->{'cmdname'}
                    or $current->{'parent'}->{'parent'}->{'cmdname'} ne 'float') {
                  $float = $current->{'parent'};
                  while ($float->{'parent'} and !($float->{'cmdname'}
                                                  and $float->{'cmdname'} eq 'float')) {
                    $float = $float->{'parent'};
                  }
                  if (!($float->{'cmdname'} and $float->{'cmdname'} eq 'float')) {
                    $self->line_error(sprintf(__(
                       "\@%s is not meaningful outside `\@float' environment"),
                                               $command), $line_nr);
                    $float = undef;
                  } else {
                    $self->line_warn(sprintf(__(
                                       "\@%s should be right below `\@float'"),
                                               $command), $line_nr);
                  }
                } else {
                  $float = $current->{'parent'}->{'parent'};
                }
                if ($float) {
                  if ($float->{'extra'}->{$command}) {
                    $self->line_warn(sprintf(__("ignoring multiple \@%s"),
                                              $command), $line_nr);
                  } else {
                    $current->{'parent'}->{'extra'}->{'float'} = $float;
                    $float->{'extra'}->{$command} = $current->{'parent'};
                  }
                }
              }
              push @{$self->{'context_stack'}}, $command;
              $line =~ s/([^\S\f\n]*)//;
              $current->{'type'} = 'brace_command_context';
              push @{$current->{'contents'}}, { 'type' => 'empty_spaces_before_argument', 
                            'text' => $1,
                            'parent' => $current,
                            'extra' => {'command' => $current->{'parent'}}
                                      };
            } else {
              $current->{'type'} = 'brace_command_arg';
              if ($brace_commands{$command}
                  and $brace_commands{$command} =~ /^\d$/
                  and $brace_commands{$command} > 0) {
                push @{$current->{'contents'}}, 
                  {'type' => 'empty_spaces_before_argument',
                            'text' => '',
                            'parent' => $current,
                            'extra' => {'command' => $current}
                                      };
              }
              push @{$self->{'context_stack'}}, $command
                if ($command eq 'inlineraw');
            }
            print STDERR "OPENED \@$current->{'parent'}->{'cmdname'}, remaining: "
              .(defined($current->{'parent'}->{'remaining_args'}) ? "remaining: $current->{'parent'}->{'remaining_args'}, " : '')
              .($current->{'type'} ? "type: $current->{'type'}" : '')."\n"
               if ($self->{'DEBUG'});
          } elsif ($current->{'parent'}
                    and (($current->{'parent'}->{'cmdname'}
                          and $current->{'parent'}->{'cmdname'} eq 'multitable')
                         or ($current->{'parent'}->{'type'} 
                             and $current->{'parent'}->{'type'} eq 'def_line'))) {
            push @{$current->{'contents'}},
                 { 'type' => 'bracketed', 'contents' => [],
                   'parent' => $current };
            $current = $current->{'contents'}->[-1];
            # we need the line number here in case @ protects end of line
            $current->{'line_nr'} = $line_nr 
              if ($current->{'parent'}->{'parent'}->{'type'}
                  and $current->{'parent'}->{'parent'}->{'type'} eq 'def_line');
            push @{$current->{'contents'}}, 
                {'type' => 'empty_spaces_before_argument',
                 'text' => '',
                 'parent' => $current,
                 'extra' => {'command' => $current}
               };
            print STDERR "BRACKETED in def/multitable\n" if ($self->{'DEBUG'});
          # lone braces accepted right in a rawpreformatted
          } elsif ($current->{'type'} 
                   and $current->{'type'} eq 'rawpreformatted') {
            push @{$current->{'contents'}}, {'text' => '{',
                                             'parent' => $current };
          # matching braces accepted in a rawpreformatted or math or ignored
          # code
          } elsif ($self->{'context_stack'}->[-1] eq 'math'
                   or $self->{'context_stack'}->[-1] eq 'rawpreformatted'
                   or $self->{'context_stack'}->[-1] eq 'inlineraw') {
            push @{$current->{'contents'}},
                 { 'type' => 'bracketed', 'contents' => [],
                   'parent' => $current, 'line_nr' => $line_nr };
            $current = $current->{'contents'}->[-1];
            print STDERR "BRACKETED in math\n" if ($self->{'DEBUG'});
          } else {
            $self->line_error(sprintf(__("misplaced %c"),
                                             ord('{')), $line_nr);
          }

        } elsif ($separator eq '}') {
          _abort_empty_line($self, $current);
          if ($current->{'type'} and ($current->{'type'} eq 'bracketed')) {
            $current = $current->{'parent'};
           # the following will not happen for footnote if there is 
           # a paragraph withing the footnote
          } elsif ($current->{'parent'}
              and $current->{'parent'}->{'cmdname'}
              and exists $brace_commands{$current->{'parent'}->{'cmdname'}}) {
            # for math and footnote out of paragraph
            if ($context_brace_commands{$current->{'parent'}->{'cmdname'}}) {
              my $context_command = pop @{$self->{'context_stack'}};
              if ($context_command ne $current->{'parent'}->{'cmdname'}) {
                $self->_bug_message("context $context_command instead of brace command $current->{'parent'}->{'cmdname'}", 
                                   $line_nr, $current);
                die;
              }
            }
            # first is the arg.
            
            if ($brace_commands{$current->{'parent'}->{'cmdname'}} 
                and $brace_commands{$current->{'parent'}{'cmdname'}} =~ /^\d$/
                and $brace_commands{$current->{'parent'}->{'cmdname'}} > 0
                and $current->{'parent'}->{'cmdname'} ne 'math') {
              # @inline* always have end spaces considered as normal text 
              _isolate_last_space($self, $current) 
                unless ($inline_commands{$current->{'parent'}->{'cmdname'}});
            }
            my $closed_command = $current->{'parent'}->{'cmdname'};
            print STDERR "CLOSING(brace) \@$current->{'parent'}->{'cmdname'}\n" 
              if ($self->{'DEBUG'});
            delete $current->{'parent'}->{'remaining_args'};
            if (defined($brace_commands{$closed_command}) 
                 and $brace_commands{$closed_command} eq '0'
                 and @{$current->{'contents'}}) {
              $self->line_warn(sprintf(__(
                                 "command \@%s does not accept arguments"), 
                                       $closed_command), $line_nr);
            }
            if ($current->{'parent'}->{'cmdname'} eq 'anchor') {
              $current->{'parent'}->{'line_nr'} = $line_nr;
              my $parsed_anchor = _parse_node_manual($current);
              if (_check_node_label($self, $parsed_anchor,
                                $current->{'parent'}->{'cmdname'}, $line_nr)) {
                _register_label($self, $current->{'parent'}, $parsed_anchor);
                if (@{$self->{'regions_stack'}}) {
                  $current->{'extra'}->{'region'} = $self->{'regions_stack'}->[-1];
                }
              }
            } elsif ($ref_commands{$current->{'parent'}->{'cmdname'}}) {
              my $ref = $current->{'parent'};
              if (@{$ref->{'args'}}) {
                my @args;
                for $a (@{$ref->{'args'}}) {
                  if (@{$a->{'contents'}}) {
                    push @args, $a->{'contents'};
                  } else {
                    push @args, undef;
                  }
                }
                if (($closed_command eq 'inforef' 
                     and !defined($args[0]) and !defined($args[2]))
                    or ($closed_command ne 'inforef'
                     and !defined($args[0]) and !defined($args[3])
                     and !defined($args[4]))) {
                  $self->line_warn(sprintf(__(
                     "command \@%s missing a node or external manual argument"),
                                        $closed_command), $line_nr);
                } else {
                  my $parsed_ref_node = _parse_node_manual($ref->{'args'}->[0]);
                  if (defined $parsed_ref_node) {
                    if ($closed_command ne 'inforef' 
                        and !defined($args[3]) and !defined($args[4])
                        and !$parsed_ref_node->{'manual_content'}) {
                      push @{$self->{'internal_references'}}, $ref;
                    }
                    $ref->{'extra'}->{'node_argument'} = $parsed_ref_node
                  }
                }
                if (defined($args[1])) {
                  my $normalized_cross_ref_name = 
                    Texinfo::Convert::NodeNameNormalization::normalize_node(
                                                      {'contents' => $args[1]});
                  if ($normalized_cross_ref_name !~ /[^-]/) {
                    $self->line_warn(sprintf(__(
                      "in \@%s empty cross reference name after expansion `%s'"),
                          $closed_command,
                          Texinfo::Convert::Texinfo::convert({'contents' => $args[1]})), 
                            $line_nr);
                  }
                }
                if ($closed_command ne 'inforef' and defined($args[2])) {
                  my $normalized_cross_ref_title =
                    Texinfo::Convert::NodeNameNormalization::normalize_node({'contents' => $args[2]});
                  if ($normalized_cross_ref_title !~ /[^-]/) {
                    $self->line_warn(sprintf(__(
                     "in \@%s empty cross reference title after expansion `%s'"),
                          $closed_command,
                          Texinfo::Convert::Texinfo::convert({'contents' => $args[2]})), 
                            $line_nr);
                  }
                }
              }
            } elsif ($current->{'parent'}->{'cmdname'} eq 'image') {
              my $image = $current->{'parent'};
              if (!@{$image->{'args'}} 
                  or !defined($image->{'args'}->[0])
                  or scalar(@{$image->{'args'}->[0]->{'contents'}}) == 0) {
                $self->line_error(
                   __("\@image missing filename argument"), $line_nr);
              }
              $image->{'extra'}->{'input_perl_encoding'}
                           = $self->{'info'}->{'input_perl_encoding'}
                                  if defined $self->{'info'}->{'input_perl_encoding'};
            } elsif($current->{'parent'}->{'cmdname'} eq 'dotless') {
              my $dotless = $current->{'parent'};
              if (@{$current->{'contents'}}) {
                my $text = $current->{'contents'}->[0]->{'text'};
                if (!defined ($text)
                  or ($text ne 'i' and $text ne 'j')) {
                  $self->line_error(sprintf(
                    __("%c%s expects `i' or `j' as argument, not `%s'"), 
                    ord('@'), $dotless->{'cmdname'}, 
                    Texinfo::Convert::Texinfo::convert($current)), $line_nr);
                }
              }
            } elsif ($explained_commands{$current->{'parent'}->{'cmdname'}}
                     or $inline_commands{$current->{'parent'}->{'cmdname'}}) {
              my $current_command = $current->{'parent'};
              if ($inline_commands{$current_command->{'cmdname'}}) {
                if ($current_command->{'cmdname'} eq 'inlineraw') {
                  my $context_command = pop @{$self->{'context_stack'}};
                  if ($context_command ne $current_command->{'cmdname'}) {
                    $self->_bug_message("context $context_command instead of inlineraw $current_command->{'cmdname'}", 
                                     $line_nr, $current);
                    die;
                  }
                }
              }
              if (!@{$current_command->{'args'}} 
                  or !defined($current_command->{'args'}->[0])
                  or scalar(@{$current_command->{'args'}->[0]->{'contents'}}) == 0) {
                $self->line_warn(
                   sprintf(__("\@%s missing first argument"),
                           $current_command->{'cmdname'}), $line_nr);
              }
            } elsif ($current->{'parent'}->{'cmdname'} eq 'errormsg') {
              my $error_message_text = $current->{'contents'}->[0]->{'text'};
              $self->line_error($error_message_text, $line_nr)
                if $error_message_text;
            } elsif ($current->{'parent'}->{'cmdname'} eq 'U') {
              my $arg;
              if ($current->{'contents'}->[0]) {
                $arg = $current->{'contents'}->[0]->{'text'};
              }
              if (!defined($arg) || !$arg) {
                $self->line_warn(__("no argument specified for \@U"),
                  $line_nr);

              } elsif ($arg !~ /^[0-9A-Fa-f]+$/) {
                $self->line_error(
            sprintf(__("non-hex digits in argument for \@U: %s"), $arg),
                  $line_nr);

              } elsif (length ($arg) < 4) {
                # Perl doesn't mind, but too much trouble to do in TeX.
                $self->line_warn(sprintf(__("fewer than four hex digits in argument for \@U: %s"), $arg),
                  $line_nr);

              } else {
                # we don't want to call hex at all if the value isn't
                # going to fit; so first use eval to check.
                # Since integer overflow is only a warning, have to make
                # warnings fatal for the eval to be effective.
                eval qq!use warnings FATAL => qw(all); hex("$arg")!;
                if ($@) {
                  # leave clue in case something else went wrong.
                  warn "\@U hex($arg) eval failed: $@\n" if ($self->{'DEBUG'});
                  # argument likely exceeds size of integer
                }
                # ok, value can be given to hex(), so try it.
                if ($@ or hex($arg) > 0x10FFFF) {
                  $self->line_error(
    sprintf(__("argument for \@U exceeds Unicode maximum 0x10FFFF: %s"),
            $arg),
                    $line_nr);
                }
              }

            } elsif (_command_with_command_as_argument($current->{'parent'}->{'parent'})
                 and scalar(@{$current->{'contents'}}) == 0) {
               print STDERR "FOR PARENT \@$current->{'parent'}->{'parent'}->{'parent'}->{'cmdname'} command_as_argument braces $current->{'cmdname'}\n" if ($self->{'DEBUG'});
               $current->{'parent'}->{'type'} = 'command_as_argument' 
                  if (!$current->{'parent'}->{'type'});
               $current->{'parent'}->{'parent'}->{'parent'}->{'extra'}->{'command_as_argument'} 
                  = $current->{'parent'};
            } elsif ($in_index_commands{$current->{'parent'}->{'cmdname'}}) {
              my $command = $current->{'parent'}->{'cmdname'};
              my @contents = @{$current->{'contents'}};
              my $arg = $current->{'contents'}->[0]->{'text'};

              if (defined($arg)) {
                my $index_element = $current->{'parent'}->{'parent'}->{'parent'};
                if ($index_element
                    and _is_index_element($self, $index_element)) {
                  $index_element->{'extra'}->{$command} = $arg;
                }
              }
            }
            _register_global_command($self, $current->{'parent'}, $line_nr);
            if ($command_ignore_space_after{$current->{'parent'}->{'cmdname'}}) {
              push @{$current->{'parent'}->{'parent'}->{'contents'}}, 
                 {'type' => 'empty_spaces_after_close_brace',
                  'text' => '',
                  'parent' => $current->{'parent'}->{'parent'}
                 };                          
            }
            $current = $current->{'parent'}->{'parent'};
            $current = _begin_preformatted ($self, $current)
               if ($close_preformatted_commands{$closed_command});
          # lone braces accepted right in a rawpreformatted
          } elsif ($current->{'type'}
                   and $current->{'type'} eq 'rawpreformatted') {
            push @{$current->{'contents'}}, {'text' => '}',
                                             'parent' => $current };
          # footnote caption closing, when there is a paragraph inside.
          } elsif ($context_brace_commands{$self->{'context_stack'}->[-1]}) {
             # closing the context under broader situations
             $current = _end_paragraph($self, $current, $line_nr);
             if ($current->{'parent'}
                 and $current->{'parent'}->{'cmdname'}
                 and $context_brace_commands{$current->{'parent'}->{'cmdname'}}
                 and $current->{'parent'}->{'cmdname'} eq $self->{'context_stack'}->[-1]) {
              my $context_command = pop @{$self->{'context_stack'}};
              if ($context_command ne $current->{'parent'}->{'cmdname'}) {
                $self->_bug_message("context $context_command instead of brace isolated $current->{'parent'}->{'cmdname'}", 
                                   $line_nr, $current);
                die;
              }
              print STDERR "CLOSING(context command) \@$current->{'parent'}->{'cmdname'}\n" if ($self->{'DEBUG'});
              my $closed_command = $current->{'parent'}->{'cmdname'};
              _register_global_command($self, $current->{'parent'}, $line_nr);
              $current = $current->{'parent'}->{'parent'};
              $current = _begin_preformatted ($self, $current)
                 if ($close_preformatted_commands{$closed_command});
            }
          } else {
            $self->line_error(sprintf(__("misplaced %c"),
                                     ord('}')), $line_nr);
          }
        } elsif ($separator eq ','
                 and $current->{'parent'}->{'remaining_args'}) {
          _abort_empty_line ($self, $current);
          _isolate_last_space($self, $current);
          my $type = $current->{'type'};
          $current = $current->{'parent'};
          if ($inline_commands{$current->{'cmdname'}}) {
            my $expandp = 0;
            if (! $current->{'extra'}->{'format'}) {
              my $inline_type;
              if (defined $current->{'args'}->[0]
                  and @{$current->{'args'}->[0]->{'contents'}}) {
                $inline_type = $current->{'args'}->[0]->{'contents'}->[0]->{'text'};
              }

              if (!$inline_type) {
                # condition is missing for some reason
                print STDERR "INLINE COND MISSING\n"
                  if ($self->{'DEBUG'});
              } elsif ($inline_format_commands{$current->{'cmdname'}}) {
                if ($self->{'expanded_formats_hash'}->{$inline_type}) { 
                  $expandp = 1;
                  $current->{'extra'}->{'expand_index'} = 1;
                } else {
                  $expandp = 0;
                }
              } elsif (($current->{'cmdname'} eq 'inlineifset'
                        and exists($self->{'values'}->{$inline_type}))
                       or ($current->{'cmdname'} eq 'inlineifclear' 
                           and ! exists($self->{'values'}->{$inline_type}))) {
                $expandp = 1;
                $current->{'extra'}->{'expand_index'} = 1;
              } else {
                $expandp = 0;
              }
              $current->{'extra'}->{'format'} = $inline_type;

              # Skip first argument for a false @inlinefmtifelse
              if (!$expandp and $current->{'cmdname'} eq 'inlinefmtifelse') {
                $current->{'extra'}->{'expand_index'} = 2;

                # Add a dummy argument for the first argument.
                push @{$current->{'args'}}, {'type' => 'elided',
                                             'parent' => $current,
                                             'contents' => []};

                # Scan forward to get the next argument.
                my $brace_count = 1;
                while ($brace_count > 0) {
                  # Forward to next comma or brace
                  if ($line =~ s/[^{,}]*([,{}])//) {
                    if ($1 eq ',' and $brace_count == 1) {
                      last;
                    } elsif ($1 eq '{') {
                      $brace_count++;
                    } elsif ($1 eq '}') {
                      $brace_count--;
                    }
                  } else {
                    my $new_text;
                    ($new_text, $line_nr) = _next_text($self, $line_nr);
                    if (!$new_text) {
                      next NEXT_LINE; # error - unbalanced brace
                    }
                    $line .= $new_text;
                  }
                }
                if ($brace_count == 0) {
                  # second arg missing
                  $line = '}' . $line;
                }
                $current->{'remaining_args'}--;
                $expandp = 1;
              }
            } elsif ($current->{'cmdname'} eq 'inlinefmtifelse') {
              # Second arg of @inlinefmtifelse when condition is true.
              # Discard second argument.
              $expandp = 0;
            }
            # If this command is not being expanded, add a dummy argument,
            # and scan forward to the closing brace.
            if (!$expandp) {
              push @{$current->{'args'}}, {'type' => 'elided',
                                           'parent' => $current,
                                           'contents' => []};
              my $brace_count = 1;
              while ($brace_count > 0) {
                if ($line =~ s/[^{}]*([{}])//) {
                  if ($1 eq '{') {
                    $brace_count++;
                  } else {
                    $brace_count--;
                  }
                } else {
                  my $new_text;
                  ($new_text, $line_nr) = _next_text($self, $line_nr);
                  if (!$new_text) {
                    next NEXT_LINE; # error - unbalanced brace
                  }
                  $line .= $new_text;
                }
              }
              $current = $current->{'args'}->[-1];
              $line = '}' . $line;
              next;
            }
          }
          $current->{'remaining_args'}--;
          push @{$current->{'args'}},
               { 'type' => $type, 'parent' => $current, 'contents' => [] };
          $current = $current->{'args'}->[-1];
          push @{$current->{'contents'}}, 
                 {'type' => 'empty_spaces_before_argument',
                  'text' => '',
                  'parent' => $current,
                  'extra' => {'command' => $current}
                };
        } elsif ($separator eq ',' and $current->{'type'}
            and $current->{'type'} eq 'line_arg'
            and $current->{'parent'}->{'cmdname'} 
            and $current->{'parent'}->{'cmdname'} eq 'node') {
          $self->line_warn(__("superfluous arguments for node"), $line_nr);
        # end of menu node (. must be followed by a space to stop the node).
        } elsif (($separator =~ /[,\t.]/ and $current->{'type'}
               and $current->{'type'} eq 'menu_entry_node')
               or ($separator eq ':' and $current->{'type'}
                 and $current->{'type'} eq 'menu_entry_name')) {
          $current = $current->{'parent'};
          push @{$current->{'args'}}, { 'type' => 'menu_entry_separator',
                                 'text' => $separator,
                                 'parent' => $current };
        } elsif ($separator eq "\f" and $current->{'type'}
                 and $current->{'type'} eq 'paragraph') {
          # form feed stops and restart a paragraph.
          $current = $self->_end_paragraph($current);
          push @{$current->{'contents'}}, {'text' => $separator, 
                                           'type' => 'empty_line',
                                            'parent' => $current };
          push @{$current->{'contents'}}, { 'type' => 'empty_line', 
                                            'text' => '',
                                            'parent' => $current };
          
        } else {
          $current = _merge_text($self, $current, $separator);
        }
      # Misc text except end of line
      } elsif (defined $misc_text) {
        my $new_text = $misc_text;
        substr ($line, 0, length ($misc_text)) = '';
        $current = _merge_text($self, $current, $new_text);
      # end of line
      } else {
        print STDERR "END LINE: ". _print_current($current)."\n"
          if ($self->{'DEBUG'});
        if ($line =~ s/^(\n)//) {
          $current = _merge_text($self, $current, $1);
        } else {
          if (scalar(@{$self->{'input'}})) {
            $self->_bug_message("Text remaining without normal text but `$line'", 
                                $line_nr, $current);
            die;
          }
        }
        $current = _end_line($self, $current, $line_nr);
        last;
      }
    }
  }
  while (@{$self->{'conditionals_stack'}}) { 
    my $end_conditional = pop @{$self->{'conditionals_stack'}};
    $self->line_error(sprintf(__("expected \@end %s"), $end_conditional), 
                      $line_nr);
  }
  $current = _close_commands($self, $current, $line_nr);

  if (@{$self->{'context_stack'}} != 1) {
    # This happens in 2 cases in the tests:
    #   @verb not closed on misc commands line
    #   def line escaped with @ ending the file
    if ($self->{'DEBUG'}) {
      print STDERR "CONTEXT_STACK no empty end _parse_texi: ".join('|', @{$self->{'context_stack'}})."\n";
    }
    @{$self->{'context_stack'}} = ('_root');
  }

  # Call 'labels_information' to initialize labels.
  my $labels = labels_information($self);
  Texinfo::Common::complete_indices($self);
  return $root;
}

# parse special line @-commands, unmacro, set, clear, clickstyle.
# Also remove spaces or ignore text, as specified in the line_commands hash.
sub _parse_special_misc_command($$$$)
{
  my ($self, $line, $command, $line_nr) = @_;

  my $args = [];

  my $has_comment = 0;
  my $remaining;
  if ($command eq 'set') {
    # REVALUE
    if ($line =~ /^\s+([\w\-][^\s{\\}~`\^+"<>|@]*)(\@(c|comment)((\@|\s+).*)?|\s+(.*?))?\s*$/) {
      if ($line =~ s/\@(c|comment)((\@|\s+).*)?$//) {
        $has_comment = 1;
      }
      $line =~ /^\s+([\w\-][^\s{\\}~`\^+"<>|@]*)(\s+(.*?))?\s*$/;
      my $name = $1;
      my $arg = $3;
      $arg = '' if (!defined($arg));
      $args = [$name, $arg];
      $self->{'values'}->{$name} = $arg;
    } elsif ($line !~ /\S/) {
      $self->line_error(sprintf(
                  __("%c%s requires a name"), ord('@'), $command), $line_nr);
    } else {
      $self->line_error(sprintf(
                    __("bad name for \@%s"), $command), $line_nr);
    }
  } elsif ($command eq 'clear') {
    # REVALUE
    if ($line =~ /^\s+([\w\-][^\s{\\}~`\^+"<>|@]*)\s*(\@(c|comment)((\@|\s+).*)?)?$/) {
      $args = [$1];
      delete $self->{'values'}->{$1};
      $has_comment = 1 if (defined($3));
    } elsif ($line !~ /\S/) {
      $self->line_error(sprintf(
                  __("%c%s requires a name"), ord('@'), $command), $line_nr);
    } else {
      $self->line_error(sprintf(
                    __("bad name for \@%s"), $command), $line_nr);
    }
  } elsif ($command eq 'unmacro') {
    # REMACRO
    if ($line =~ /^\s+([[:alnum:]][[:alnum:]\-]*)\s*(\@(c|comment)((\@|\s+).*)?)?$/) {
      $args = [$1];
      delete $self->{'macros'}->{$1};
      $has_comment = 1 if (defined($3));
      print STDERR "UNMACRO $1\n" if ($self->{'DEBUG'});
    } elsif ($line !~ /\S/) {
      $self->line_error(sprintf(
                  __("%c%s requires a name"), ord('@'), $command), $line_nr);
    } else {
      $self->line_error(sprintf(
                    __("bad name for \@%s"), $command), $line_nr);
    }
  } elsif ($command eq 'clickstyle') {
    # REMACRO
    if ($line =~ /^\s+@([[:alnum:]][[:alnum:]\-]*)(\{\})?\s*/) {
      $args = ['@'.$1];
      $self->{'clickstyle'} = $1;
      $remaining = $line;
      $remaining =~ s/^\s+@([[:alnum:]][[:alnum:]\-]*)(\{\})?\s*(\@(c|comment)((\@|\s+).*)?)?//;
      $has_comment = 1 if (defined($4));
    } else {
      $self->line_error (sprintf(__(
                "\@%s should only accept an \@-command as argument, not `%s'"),
                                 $command, $line), $line_nr);
    }
  } else {
    die $self->_bug_message("Unknown special command $command", $line_nr);
  }
  if (defined($remaining)) {
    chomp($remaining);
    if ($remaining ne '') {
      $self->line_warn(sprintf(__(
                         "remaining argument on \@%s line: %s"), 
                           $command, $remaining), $line_nr);
    }
  }
  return ($args, $has_comment);
}

# at the end of an @-command line with arguments, parse the resulting 
# text, to collect aliases, definfoenclose and collect errors on 
# wrong arguments.
sub _parse_line_command_args($$$)
{
  my ($self, $line_command, $line_nr) = @_;

  my $args;

  my $command = $line_command->{'cmdname'};
  my $arg = $line_command->{'args'}->[0];

  if ($self->{'DEBUG'}) {
    print STDERR "MISC ARGS \@$command\n";
    if (@{$arg->{'contents'}}) {
      my $idx = 0;
      foreach my $content (@{$arg->{'contents'}}) {
        my $name = '';
        $name = '@' . $content->{'cmdname'} if ($content->{'cmdname'});
        my $type = ', t: ';
        $type .= $content->{'type'} if ($content->{'type'});
        my $text = ', ';
        $type .= $content->{'text'} if ($content->{'text'});
        print STDERR "   -> $idx $name $type $text\n";
        $idx++;
      }
    }
  }

  if (!$arg->{'contents'} or !@{$arg->{'contents'}}) {
    $self->_command_error($line_command, $line_nr,
               __("\@%s missing argument"), $command);
    $line_command->{'extra'}->{'missing_argument'} = 1;
    return undef;
  }

  if (@{$arg->{'contents'}} > 1
         or (!defined($arg->{'contents'}->[0]->{'text'}))) {
    $self->line_error (sprintf(__("superfluous argument to \@%s"),
       $command), $line_nr);
  }
  return undef if (!defined($arg->{'contents'}->[0]->{'text'}));
  
  my $line = $arg->{'contents'}->[0]->{'text'};  

  if ($command eq 'alias') {
    # REMACRO
    if ($line =~ s/^([[:alnum:]][[:alnum:]-]*)(\s*=\s*)([[:alnum:]][[:alnum:]-]*)$//) {
      my $new_command = $1;
      my $existing_command = $3;
      $args = [$1, $3];
      $self->{'aliases'}->{$new_command} = $existing_command;
      if (exists($block_commands{$existing_command})) {
        $self->line_warn(sprintf(
                             __("environment command %s as argument to \@%s"), 
                             $existing_command, $command), $line_nr);
      }
    } else {
      $self->line_error(sprintf(
                             __("bad argument to \@%s"), $command), $line_nr);
    }

  } elsif ($command eq 'definfoenclose') {
    # REMACRO
    if ($line =~ s/^([[:alnum:]][[:alnum:]\-]*)\s*,\s*([^\s,]*)\s*,\s*([^\s,]*)$//) {
      $args = [$1, $2, $3 ];
      $self->{'definfoenclose'}->{$1} = [ $2, $3 ];
      print STDERR "DEFINFOENCLOSE \@$1: $2, $3\n" if ($self->{'DEBUG'});

      $brace_commands{$1} = 'style';

      # Warning: there is a risk of mixing of data between a built-in 
      # command and a user command defined with @definfoenclose.
      # %keep_line_nr_brace_commands is one example of this.
    } else {
      $self->line_error(sprintf(
                              __("bad argument to \@%s"), $command), $line_nr);
    }
  } elsif ($command eq 'columnfractions') {
    my @possible_fractions = split (/\s+/, $line);
    if (!@possible_fractions) {
      $self->line_error (sprintf(__("empty \@%s"), $command), 
                             $line_nr);
    } else {
      foreach my $fraction (@possible_fractions) {
        if ($fraction =~ /^\d*\.\d+$|^\d+\.?$/) {
          push @$args, $fraction;
        } else {
          $self->line_error (sprintf(
                              __("column fraction not a number: %s"),
                              $fraction), $line_nr);
        }
      }
    }
  } elsif ($command eq 'sp') {
    if ($line =~ /^([0-9]+)$/) {
      $args = [$1];
    } else {
      $self->line_error(sprintf(__("\@sp arg must be numeric, not `%s'"), 
                                $line), $line_nr);
    }
  } elsif ($command eq 'defindex' || $command eq 'defcodeindex') {
    # REMACRO
    if ($line =~ /^([[:alnum:]][[:alnum:]\-]*)$/) {
      my $name = $1;
      if ($forbidden_index_name{$name}) {
        $self->line_error(sprintf(
                                __("reserved index name %s"),$name), $line_nr);
      } else {
        my $in_code = 0;
        $in_code = 1 if ($command eq 'defcodeindex');
        $args = [$name];
        $self->{'index_names'}->{$name} = {'in_code' => $in_code};
        if (!exists($self->{'index_names'}->{$name}->{'name'})) {
          $self->{'index_names'}->{$name}->{'name'} = $name;
        }
        if (!exists($self->{'index_names'}->{$name}->{'contained_indices'})) {
          $self->{'index_names'}->{$name}->{'contained_indices'}->{$name} = 1;
        }
        $self->{'line_commands'}->{$name.'index'} = 'line';
        $self->{'no_paragraph_commands'}->{$name.'index'} = 1;
        $self->{'valid_nestings'}->{$name.'index'} = \%in_simple_text_commands;
        $self->{'command_index'}->{$name.'index'} = $name;
      }
    } else {
      $self->line_error(sprintf(
                   __("bad argument to \@%s: %s"), $command, $line), $line_nr);
    }
  } elsif ($command eq 'synindex' || $command eq 'syncodeindex') {
    # REMACRO
    if ($line =~ /^([[:alnum:]][[:alnum:]\-]*)\s+([[:alnum:]][[:alnum:]\-]*)$/) {
      my $index_from = $1;
      my $index_to = $2;
      $self->line_error(sprintf(__("unknown source index in \@%s: %s"),
                                  $command, $index_from), $line_nr)
        unless $self->{'index_names'}->{$index_from};
      $self->line_error(sprintf(__("unknown destination index in \@%s: %s"), 
                                 $command, $index_to), $line_nr)
        unless $self->{'index_names'}->{$index_to};
      if ($self->{'index_names'}->{$index_from} 
           and $self->{'index_names'}->{$index_to}) {
        my $current_to = $index_to;
        # find the merged indices recursively avoiding loops
        while ($current_to ne $index_from 
               and $self->{'merged_indices'}->{$current_to}) {
          $current_to = $self->{'merged_indices'}->{$current_to};
        }
        if ($current_to ne $index_from) {
          my $index_from_info = $self->{'index_names'}->{$index_from};
          my $index_to_info = $self->{'index_names'}->{$current_to};

          my $in_code = 0;
          $in_code = 1 if ($command eq 'syncodeindex');
          $self->{'merged_indices'}->{$index_from} = $current_to;
          $index_from_info->{'in_code'} = $in_code;
          foreach my $contained_index (keys %{$index_from_info->{'contained_indices'}}) {
            $index_to_info->{'contained_indices'}->{$contained_index} = 1;
            $self->{'index_names'}->{$contained_index}->{'merged_in'} = $current_to;
            $self->{'merged_indices'}->{$contained_index} = $current_to;
          }
          delete $index_from_info->{'contained_indices'};
          $index_from_info->{'merged_in'} = $current_to;
          $index_to_info->{'contained_indices'}->{$index_from} = 1;
          $args = [$index_from, $index_to];
        } else {
          $self->line_warn(sprintf(__(
                         "\@%s leads to a merging of %s in itself, ignoring"), 
                             $command, $index_from), $line_nr);
        }
      }
    } else {
      $self->line_error(sprintf(__("bad argument to \@%s: %s"), 
                                $command, $line), $line_nr);
    }
  } elsif ($command eq 'printindex') {
    # REMACRO
    if ($line =~ /^([[:alnum:]][[:alnum:]\-]*)$/) {
      my $name = $1;
      if (!exists($self->{'index_names'}->{$name})) {
        $self->line_error(sprintf(__("unknown index `%s' in \@printindex"),
                                    $name), $line_nr);
      
      } else {
        if ($self->{'merged_indices'}->{$name}) {
          $self->line_warn(sprintf(__(
                       "printing an index `%s' merged in another one, `%s'"), 
                                   $name, $self->{'merged_indices'}->{$name}),
                           $line_nr); 
        }
        if (!defined($self->{'current_node'}) 
            and !defined($self->{'current_section'})
            and !scalar(@{$self->{'regions_stack'}})) {
          $self->line_warn(sprintf(__(
                     "printindex before document beginning: \@printindex %s"), 
                                    $name), $line_nr);
        }
        $args = [$name];
      }
    } else {
      $self->line_error(sprintf(
                   __("bad argument to \@%s: %s"), $command, $line), $line_nr);
    }
  } elsif (grep {$_ eq $command} ('everyheadingmarks', 'everyfootingmarks',
                                  'evenheadingmarks', 'oddheadingmarks',
                                  'evenfootingmarks', 'oddfootingmarks')) {
    if ($line eq 'top' or $line eq 'bottom') {
      $args = [$line];
    } else {
      $self->line_error(sprintf(__(
                      "\@%s arg must be `top' or `bottom', not `%s'"), 
                                $command, $line), $line_nr);
    }
  } elsif ($command eq 'fonttextsize') {
    if ($line eq '10' or $line eq '11') {
      $args = [$line];
    } else {
      $self->line_error(sprintf(__(
                        "Only \@%s 10 or 11 is supported, not `%s'"),
                                $command, $line), $line_nr);
    }
  } elsif ($command eq 'footnotestyle') {
    if ($line eq 'separate' or $line eq 'end') {
      $args = [$line];
    } else {
      $self->line_error(sprintf(__(
                            "\@%s arg must be `separate' or `end', not `%s'"), 
                                $command, $line), $line_nr);
    }
  } elsif ($command eq 'setchapternewpage') {
    if ($line eq 'on' or $line eq 'off' or $line eq 'odd') {
      $args = [$1];
    } else {
      $self->line_error(sprintf(__(
                           "\@%s arg must be `on', `off' or `odd', not `%s'"), 
                                 $command, $line), $line_nr);
    }
  } elsif ($command eq 'need') { # only a warning
    if (($line =~ /^([0-9]+(\.[0-9]*)?)$/) or
             ($line =~ /^(\.[0-9]+)$/)) {
      $args = [$1];
    } else {
      $self->line_error(sprintf(__("bad argument to \@%s: %s"), 
                                 $command, $line), $line_nr);
    }
  } elsif ($command eq 'paragraphindent') {
    if ($line =~ /^([\w\-]+)$/) {
      my $value = $1;
      if ($value =~ /^([0-9]+)$/ or $value eq 'none' or $value eq 'asis') {
        $args = [$1];
      } else {
        $self->line_error(sprintf(__(
           "\@paragraphindent arg must be numeric/`none'/`asis', not `%s'"), 
                                             $value), $line_nr);
      } 
    } else {
      $self->line_error(sprintf(__(
             "\@paragraphindent arg must be numeric/`none'/`asis', not `%s'"), 
                                           $line), $line_nr);
    }
  } elsif ($command eq 'firstparagraphindent') {
    if ($line eq 'none' or $line eq 'insert') {
      $args = [$line];
    } else {
      $self->line_error(sprintf(__(
         "\@firstparagraphindent arg must be `none' or `insert', not `%s'"), 
                                           $line), $line_nr);
    }
  } elsif ($command eq 'exampleindent') {
    if ($line =~ /^([0-9]+)$/) {
      $args = [$1];
    } elsif ($line =~ /^(asis)$/) {
      $args = [$1];
    } else {
      $self->line_error(sprintf(__(
           "\@exampleindent arg must be numeric/`asis', not `%s'"), 
                                           $line), $line_nr);
    }
  } elsif ($command eq 'frenchspacing' 
           or $command eq 'xrefautomaticsectiontitle'
           or $command eq 'codequoteundirected'
           or $command eq 'codequotebacktick'
           or $command eq 'validatemenus'
           or $command eq 'deftypefnnewline') {
    if ($line eq 'on' or $line eq 'off') {
      $args = [$line];
    } else {
      $self->line_error(sprintf(__("expected \@%s on or off, not `%s'"), 
                                           $command, $line), $line_nr);
    }
  } elsif ($command eq 'kbdinputstyle') {
    if ($line eq 'code' or $line eq 'example' or $line eq 'distinct') {
      $self->{'kbdinputstyle'} = $line;
      $args = [$line];
    } else {
      $self->line_error(sprintf(__(
      "\@kbdinputstyle arg must be `code'/`example'/`distinct', not `%s'"), 
                                           $line), $line_nr);
    }
  } elsif ($command eq 'allowcodebreaks') {
    if ($line eq 'true' or $line eq 'false') {
      $args = [$line];
    } else {
      $self->line_error(sprintf(__(
               "\@allowcodebreaks arg must be `true' or `false', not `%s'"), 
                                           $line), $line_nr);
    }
  } elsif ($command eq 'urefbreakstyle') {
    if ($line eq 'after' or $line eq 'before' or $line eq 'none') {
      $args = [$line];
    } else {
      $self->line_error(sprintf(__(
         "\@urefbreakstyle arg must be `after'/`before'/`none', not `%s'"), 
                                           $line), $line_nr);
    }
  } elsif ($command eq 'headings') {
    if ($line eq 'off' or $line eq 'on' or $line eq 'single' 
       or $line eq 'double' or  $line eq 'singleafter' or $line eq 'doubleafter') {
      $args = [$line];
    } else {
      $self->line_error(sprintf(__("bad argument to \@%s: %s"), 
                                 $command, $line), $line_nr);
    }
  }
  return $args;
}

1;
__END__
=head1 NAME

Texinfo::Parser - Parse Texinfo code into a Perl tree

=head1 SYNOPSIS

  use Texinfo::Parser;
  my $parser = Texinfo::Parser::parser();
  my $tree = $parser->parse_texi_file("somefile.texi");
  my ($errors, $errors_count) = $parser->errors();
  foreach my $error_message (@$errors) {
    warn $error_message->{'error_line'};
  }

  my $index_names = $parser->indices_information();
  my $float_types_arrays = $parser->floats_information();
  my $internal_references_array
    = $parser->internal_references_information();
  # An hash reference on normalized node/float/anchor names
  my $labels_information = $parser->labels_information();
  # A hash reference, keys are @-command names, value is an 
  # array reference holding all the corresponding @-commands.
  my $global_commands_information = $parser->global_commands_information();
  # a hash reference on some document informations (encodings, 
  # input file name, dircategory and direntry list, for exampel).
  my $global_informations = $parser->global_informations();

=head1 DESCRIPTION

Texinfo::Parser will parse Texinfo text into a perl tree.  In one pass
it expands user-defined @-commands, conditionals (@ifset, @ifinfo...)
and @value and constructs the tree.  Some extra information is gathered
while doing the tree: for example, the block command associated with @end,
the number of rows in a multitable, or the node associated with a section.



=head1 METHODS

No method is exported in the default case.  The module allows both
an object-oriented syntax, or traditional function, with the parser
as an opaque data structure given as an argument to every function.

=head2 Initialization

The following method is used to construct a new C<Texinfo::Parser> object:

=over

=item $parser = Texinfo::Parser::parser($options);

This method creates a new parser.  The options may be provided as a hash
reference.  There are two types of option.  The first type of option
change the way the parser behaves; they are described right here.  The 
other type of option allows giving the parser some information as if 
it came from texinfo code; for example, allow setting aliases (as with 
C<@alias>), values (as with C<@set>), or merged indices (as with 
C<@synindex>).  These options are described below in L</Texinfo Parser options>.

=over

=item expanded_formats

An array reference of the output formats for which C<@ifI<FORMAT>> 
conditional blocks should be expanded.  Default is empty.

=item include_directories

An array reference of directories in which C<@include> files should be 
searched for.  Default contains the working directory, F<.>.

=item IGNORE_BEFORE_SETFILENAME

If set, and C<@setfilename> exists, everything before C<@setfilename>
is put in a special container type, @C<preamble_before_setfilename>.
This option is set in the default case.

=item IGNORE_SPACE_AFTER_BRACED_COMMAND_NAME

If set, spaces after an @-command name that take braces are ignored.
Default on.

=item MAX_MACRO_CALL_NESTING

Maximal number of nested user-defined macro calls.  Default is 100000.

=item SHOW_MENU

If false, no menu-related errors are reported.  Default is true.

=begin :comment

Used by Sectioning only
=item TOP_NODE_UP

Text for the up node of the Top node.  The default is C<(dir)>.  The
string may contain @-commands.

=end :comment

=back

=back

=head2 Parsing Texinfo text

There are three methods that may be called to parse some Texinfo code:
C<parse_texi_line> for a line, C<parse_texi_text> for a text fragment, 
and C<parse_texi_file> for a file.

For all those functions, if the I<$parser> argument is undef, a new 
parser object is generated to parse the line.  Otherwise the parser given 
as an argument is used to parse into a tree.

When C<parse_texi_text> is used, the resulting tree is rooted at 
a C<root_line> type container.  Otherwise, the resulting tree should be 
rooted at a C<text_root> type container if it does not contain nodes or 
sections, at a C<document_root> type container otherwise.

=over

=item $tree = parse_texi_line($parser, $text, $first_line_number, $file_name, $macro_name, $fixed_line_number)

This function is used to parse a short fragment of Texinfo code.

I<$text> may be either an array reference of lines, or a text.

The other arguments are optional and allow specifying the position
information of the Texinfo code.  I<$first_line_number> is the line number
of the first text line.  I<$file_name> is the name of the file the
text comes from.  I<$macro> is for the user-defined macro name the text
is expanded from.  If I<$fixed_line_number> is set, the line number is
not increased for the different lines, as if the text was the expansion
of a macro.

=item $tree = parse_texi_text ($parser, $text, $line_numbers_specification, $file_name, $macro_name, $fixed_line_number)

This function is used to parse some Texinfo text.

I<$text> may be either an array reference of lines, or a text.

The other arguments are optional and allow specifying the position
information of the Texinfo code.  There are two distinct cases for 
I<$line_numbers_specification>.  

=over

=item 1.

If it is an array reference, it is considered to hold objects describing 
the position information of each text line.

=item 2.

If I<$line_numbers_specification> is a scalar, it is the line number of 
the first text line.  In that case (like for C<parse_texi_text>), 
I<$file_name> is the name of the file the text comes from.  
and I<$macro> is for the user-defined macro name the text
is expanded from.  If I<$fixed_line_number> is set, the line number is
not increased for the different lines, as if the text was the expansion
of a macro.

=back

=item $tree = parse_texi_file($parser, $file_name)

The file with name I<$file_name> is considered to be a Texinfo file and
is parsed into a tree.

undef is returned if the file couldn't be read.

=back

The errors collected during the tree parsing are available through the
C<errors> method.  This method comes from C<Texinfo::Report>, and is 
described in L<errors|Texinfo::Report/($error_warnings_list, $error_count) = errors ($converter)>.

=head2 Getting information on the document

After parsing some information about the Texinfo code that was processed
is available from the parser.

Some global information is available through C<global_informations>

=over

=item $info = global_informations($parser)

The I<$info> returned is a hash reference.  The possible keys are

=over

=item input_file_name

The name of the main Texinfo input file.

=item input_encoding_name

=item input_perl_encoding

C<input_encoding_name> string is the encoding name used for the 
Texinfo code.
C<input_perl_encoding> string is a corresponding perl encoding name.

=item dircategory_direntry

An array of successive C<@dircategory> and C<@direntry> as they appear
in the document.

=item novalidate

If set, it is as if C<@novalidate> was set in the document.


=back

=back

Some command lists are available, such that it is possible to go through
the corresponding tree elements without walking the tree.  They are
available through C<global_commands_information>

=over

=item $commands = global_commands_information($parser)

I<$commands> is an hash reference.  The keys are @-command names.  The 
associated values are array references containing all the corresponding
tree elements.

=back

All the @-commands that have an associated label (so can be the
target of cross references) - C<@node>, C<@anchor> and C<@float> with
label - have a normalized name associated, constructed as described in the
B<HTML Xref> node in the Texinfo manual.  Those normalized labels and
the association with @-commands is available through C<labels_information>:

=over

=item $labels_information = labels_information($parser)

I<$labels_information> is a hash reference whose keys are normalized
labels, and the associated value is the corresponding @-command.

=back

Information on C<@float> is also available, grouped by type of 
floats, each type correponding to potential C<@listoffloats>.
This information is available through the method C<floats_information>.

=over

=item $float_types = floats_information($parser)

I<$float_types> is a hash reference whose keys are normalized float
types (the first float argument, or the C<@listoffloats> argument).
The normalization is the same as for node names. The value is the list
of float tree elements appearing in the texinfo document.

=back

Internal references, that is, @-commands that refer to node, anchors
or floats within the document are also available:

=over

=item $internal_references_array = internal_references_information($parser);

The function returns a list of cross-reference commands referring to
the same document.

=back

Information about defined indices, merged indices and index entries is
also available through the C<indices_information> method.

=over

=item indices_information

  $index_names = indices_information($parser);

The index names is a hash reference.  The keys are

=over

=item in_code

1 if the index entries should be formatted as code, 0 in the opposite case.

=item name

The index name.

=item prefix

An array reference of prefix associated to the index.

=item merged_in

In case the index is merged to another index, this key holds the name of 
the index the index is merged into.  It takes into account indirectly
merged indices.

=item contained_indices

An hash reference holding names of indices that are merged into the index,
including itself.  It also contains indirectly merged indices.  This key 
is removed if the index is itself later merged to another index.

=item index_entries

An array reference containing index entry structures for index entries 
associated with the index.  The index entry could be associated to 
@-commands like C<@cindex>, or C<@item> in C<@vtable>, or definition 
commands entries like C<@deffn>.

The keys of the index entry structures are

=over

=item index_name

The index name.

=item index_at_command

The name of the @-command associated with the index entry.

=item index_type_command

The @-command associated with the index entry allowing to 
find the index type.

=item content

An array reference corresponding to the index entry content.

=item content_normalized

An array reference corresponding to the index entry content, independent
of the current language.

=item command

The element in the parsed tree associated with the @-command holding the 
index entry.

=item node

The node in the parsed tree containing the index entry.

=item number

The number of the index entry.

=item region

The region command (C<@copying>, C<@titlepage>) containing the index entry,
if it is in such an environement.

=back

=back

The following shows the references corresponding to the default indexes
I<cp> and I<fn>, the I<fn> index having its entries formatted as code and 
the indices corresponding to the following texinfo

  @defindex some
  @defcodeindex code

  $index_names = {'cp' => {'name' => 'cp', 'in_code' => 0, },
                  'fn' => {'name' => 'fn', 'in_code' => 1, },
                  'some' => {'in_code' => 0},
                  'code' => {'in_code' => 1}};

If C<name> is not set, it is set to the index name.

=back

=head2 Texinfo Parser options

Setting these options is the same as seeing some Texinfo constructs in the 
document.

=over

=item aliases

A hash reference.  The key is a command name, the value is the alias, as
could be set by C<@alias>.

=item clickstyle

A string, the command name associated with C<@clickstyle>.

=item documentlanguage

A string corresponding to a document language set by C<@documentlanguage>.

=item indices

If it is a hash reference, the keys are index names, the values are
index prefix hash references.  The index prefix hash reference values are
prefix, the value is set if the corresponding index entries should be
formatted as if in C<@code>.  An example is as L</indices_information>.

If it is an array reference, it is a list of index names, as if they were
entered as

  @defindex name

=item kbdinputstyle

A string, the C<@kbdinputstyle> style.

=item labels

A hash reference.  Keys are normalized node names as described in the
B<HTML Xref> node in the Texinfo manual.  Instead of a node, it may also
be a float label or an anchor name.  The value is the corresponding 
@-command element in the tree.

=item macros

The associated hash reference has as keys user-defined macro names.  The
value is the reference on a macro definition element as obtained by 
the Parser when parsing a C<@macro>.  For example

  @macro mymacro{arg}
  coucou \arg\ after arg
  @end macro

Is associated to a macro definition element

  {'cmdname' => 'macro',
   'args' => [{'text' => 'mymacro', 'type' => 'macro_name'},
              {'text' => 'arg', 'type' => 'macro_arg}],
   'contents' => [{'text' => "coucou \arg\ after arg\n", 'type' => 'raw'}],
   'extra' => {'arg_line' => " mymacro{arg}\n", }}

= item merged_indices

The associated hash reference holds merged indices information, each key 
is merged in the value.  Same as setting C<@synindex> or C<syncodeindex>.

=item sections_level

Modifier of the sections level.  Same as calling C<@lowersections> or
C<@raisesections>.

=item values

A hash reference.  Keys are names, values are the corresponding values.
Same as values set by C<@set>.

=back

=head1 TEXINFO TREE

A Texinfo tree element (called element because node is overloaded in 
the Texinfo world) is an hash reference.  There are three main categories
of tree element.  Tree elements associated with an @-command have a 
C<cmdname> key holding the @-command name.  Tree elements corresponding
to text fragments have a C<text> key holding the corresponding text.
Finally, the last category is other containers (hereafter called 
containers) which in most cases have a C<type> key holding their name.  
Text fragments and @-command elements may also have an associated type 
when such information is needed.

The children of an @-command or container element are in the array
referred to with the C<args> key or with the C<contents> key.  The
C<args> key is for arguments of @-commands, either in braces or on
the rest of the line after the command, depending on the type of command.
C<args> is also used for the elements of a menu entry, as a menu
entry is well-structured with a limited number of arguments.  
The C<contents> key array holds the contents of the texinfo 
code appearing within a block @-command, within a container, 
or within a C<@node> or sectioning @-command.

Another important key for the elements is the C<extra> key which is 
associated to a hash reference and holds all kinds of information that
is gathered during the parsing and may help with the conversion.

You can see examples of the tree structure by running makeinfo like 
this:

  makeinfo -c DUMP_TREE=1 -c TEXINFO_OUTPUT_FORMAT=parse document.texi

For a simpler, more regular representation of the tree structure, you 
can do:

  makeinfo -c TEXINFO_OUTPUT_FORMAT=debugtree document.texi

=head2 Element keys

=over

=item cmdname

The command name of @-command elements.

=item text

The text fragment of text elements.

=item type

The type of the element.  For C<@verb> it is the delimiter.  But otherwise
it is the type of element considered as a container.  Frequent types 
encountered are I<paragraph> for a paragraph container, 
I<brace_command_arg> for the container holding the brace @-commands 
contents, I<line_arg> and I<block_line_arg> contain the arguments 
appearing on the line of @-commands.  Text fragments may have a type to
give an information of the kind of text fragment, for example 
C<empty_spaces_before_argument> is associated to spaces after a brace 
opening and before the argument.  Many @-commands elements don't have
a type associated.

=item args

Arguments in braces or on @-command line, and the elements of a menu entry.

=item contents

The Texinfo appearing in the element.  For block commands, other 
containers, C<@node> and sectioning commands.

=item parent

The parent element.

=item line_nr

An hash reference corresponding to information on the location of the 
element in the Texinfo input manual.  It should only be available for 
@-command elements, and only for @-commands that are considered to be 
complex enough that the location in the document is needed, for example 
to prepare an error message.  

The keys of the line number hash references are

=over

=item line_nr

The line number of the @-command.

=item file_name

The file name where @-command appeared.

=item macro

The user macro name the @-command is expanded from.

=back

=item extra

A hash reference holding any additional information. 
See L</Information available in the extra key>.

=back

=head2 Element types

=head3 Types for command elements

Some types can be associated with @-commands (in addition to the element 
being described by C<cmdname>), although usually there will be no type 
at all.  As said above, for C<@verb> the type is the delimiter.  For a 
C<@value> command that is not expanded because there is no corresponding 
value set, the type is the value argument string.  

The following are the other possible values of C<type> for tree elements 
for @-commands.

=over

=item def_line

This type may be associated with a definition command with a x form,
like C<@defunx>, C<@defvrx>.  For the form without x, the associated
I<def_line> is the first C<contents> element.  It is described in more
details below.

=item command_as_argument

This is the type of a command given in argument of C<@itemize>, 
C<@table>, C<@vtable> or C<@ftable>.  For example in 

 @itemize @bullet
 @item item
 @end itemize

the element corresponding with bullet has the following keys:

  'cmdname' => 'bullet'
  'type' => 'command_as_argument'

The parent @-command has an entry in extra for the I<command_as_argument>
element:

  'cmdname' => 'itemize'
  'extra => {'command_as_argument' => $command_element_as_argument}

=item index_entry_command

This is the type of index entry command like C<@cindex>, and, more
importantly user-defined index entry commands.  So for example if there
is 

 @defindex foo
  ...

 @fooindex index entry

the C<@fooindex> @-command element will have the I<index_entry_command>
type.

=item following_arg

This type is set for non-alphabetic accent @-commands that don't use braces
but instead have their argument right after them, as

  @~n

=item space_command_arg

This type is set for accent @-commands that don't use brace but instead
have their argument after some space, as

  @ringaccent A

=item definfoenclose_command

This type is set for an @-command that is redefined by C<@definfoenclose>.
The beginning is in C<< {'extra'}->{'begin'} >> and the end in 
C<< {'extra'}->{'end'} >>.

=back

=head3 Types for text elements

The text elements may have the following types (or may have no type
at all):

=over

=item empty_line

An empty line (possibly containing whitespace characters only).

=item empty_line_after_command

=item empty_spaces_after_command

The text is spaces for I<empty_spaces_after_command> 
or spaces followed by a newline for 
I<empty_line_after_command>, appearing after an @-command that 
takes an argument on the line or a block @-command.

=item empty_spaces_before_argument

The text is spaces appearing after an opening brace or after a 
comma separating a command's arguments.

=item spaces_at_end

Space at the end of an argument to a line command, at the end of an
comma-separated argument for some brace commands, or at the end of
bracketed content on a C<@multitable> line or definition line.

=item empty_spaces_after_close_brace

Spaces appearing after a closing brace, for some rare commands for which
this space should be ignorable (like C<@caption>).

=item empty_spaces_before_paragraph

Space appearing before a paragraph beginning.

=item raw

Text in an environment where it should be kept as is (in C<@verbatim>,
C<@verb>, C<@html>, C<@macro> body).

=item last_raw_newline

The last end of line in a raw block (except for C<@verbatim>).

=item preamble_text

Text appearing before real content, including the C<\input texinfo.tex>. 

=item space_at_end_menu_node

=item after_description_line

Space after a node in the menu entry, when there is no description,
and space appearing after the description line.

=back

=head3 Types of container elements

The other types of element are the following.  These are containers with 
other elements appearing in their C<contents>.

=over

=item text_root

=item document_root

=item root_line

These types correspond to document roots.  C<text_root> is the document
root when there is no C<@node> or sectioning command.  When
such a command appears, a new root container is used, C<document_root>,
and C<text_root> becomes the first element in the contents of C<document_root>.
C<root_line> is the type of the root tree when parsing Texinfo line
fragments using C<parse_texi_line>.

=item preamble

This container holds the text appearing before the first content, including
the C<\input texinfo.tex> line and following blank lines.

=item preamble_before_setfilename

This container holds everything that appears before C<@setfilename>
if I<IGNORE_BEFORE_SETFILENAME> parser option is set.

=item paragraph

A paragraph.  The C<contents> of a paragraph (like other container 
elements for Texinfo content) are elements representing the contents of 
the paragraph in the order they occur, such as simple text elements 
without a C<cmdname> or C<type>, or @-command elements for commands 
appearing in the paragraph.

=item preformatted

Texinfo code within a format that is not filled.  Happens within some
block commands like C<@example>, but also in menu (in menu descriptions,
menu comments...).

=item brace_command_arg

=item brace_command_context

=item line_arg

=item block_line_arg

Those containers occur within the C<args> array of @-commands taking an 
argument.  I<brace_command_arg> is used for the arguments to commands
taking arguments surrounded by braces (and in some cases separated by 
commas).  I<brace_command_context> is used for @-commands with braces 
that start a new context (C<@footnote>, C<@caption>, C<@math>).

I<line_arg> is used for commands that take the texinfo code on the
rest of the line as their argument (for example (C<@settitle>, C<@node>, 
C<@section> and similar).  I<block_line_arg> is similar but is used for 
commands that start a new block (which is to be ended with C<@end>).

For example

 @code{in code}

leads to

 {'cmdname' => 'code',
  'args' => [{'type' => 'brace_command_arg',
              'contents' => [{'text' => 'in code'}]}]}

=item misc_arg

Used for the arguments to some special line commands whose arguments
aren't subject to the usual macro expansion.  For example C<@set>, 
C<@clickstyle>, C<@unmacro>, C<@comment>.  The argument is associated to 
the I<text> key.

=item menu_entry

=item menu_entry_leading_text

=item menu_entry_name

=item menu_entry_separator

=item menu_entry_node

=item menu_entry_description

A I<menu_entry> holds a full menu entry, like

  * node::    description.

The different elements of the menu entry are directly in the 
I<menu_entry> C<args> array reference.

I<menu_entry_leading_text> holds the star and following spaces. 
I<menu_entry_name> is the menu entry name (if present), I<menu_entry_node>
corresponds to the node in the menu entry, I<menu_entry_separator> holds
the text after the node and before the description, in most cases
C<::   >.  Lastly, I<menu_entry_description> is for the description.

=item menu_comment

The I<menu_comment> container holds what is between menu entries 
in menus.  For example in 

  @menu
  Menu title

  * entry::

  Between entries
  * other::
  @end menu

Both 

  Menu title

and

  Between entries

will be in I<menu_comment>.

=item macro_name

=item macro_arg

Taken from C<@macro> definition and put in the C<args> key array of
the macro, I<macro_name> is the type of the text fragment corresponding 
to the macro name, I<macro_arg> is the type of the text fragments 
correponding to macro formal arguments.

=item before_item

A container for content before the first C<@item> of block @-commands
with items (C<@table>, C<@multitable>, C<@enumerate>...).

=item table_entry

=item table_term

=item table_item

=item inter_item

Those containers appear in C<@table>, C<@ftable> and C<@vtable>.
A I<table_entry> container contains an entire row of the table.
It contains a I<table_term> container, which holds all the C<@item> and
C<@itemx> lines.  This is followed by a I<table_item> container, which
holds the content that is to go into the second column of the table.

If there is any content before an C<@itemx> (normally only comments, 
empty lines or maybe index entries are allowed), it will be in 
a container with type I<inter_item>. 

=item def_line

=item def_item

=item inter_def_item

The I<def_line> type is either associated with a container within a
definition command, or is the type of a definition command with a x
form, like C<@deffnx>.  It holds the definition line arguments.
The container with type I<def_item> holds the definition text content.
Content appearing before a definition command with a x form is in
an I<inter_def_item> container.

=item multitable_head

=item multitable_body

=item row

In C<@multitable>, a I<multitable_head> container contains all the rows
with C<@headitem>, while I<multitable_body> contains the rows associated
with C<@item>.  A I<row> container contains the C<@item> and @<tab> 
forming a row.

=item bracketed

This a special type containing content in brackets in the context
where they are valid, in C<@math>.

=item bracketed_def_content

Content in brackets on definition command lines.

=item def_aggregate

Contains several elements that together are a single unit on a @def* line.

=item bracketed_multitable_prototype

=item row_prototype

On C<@multitable> line, content in brackets is in 
I<bracketed_multitable_prototype>, text not in brackets
is in I<row_prototype>.

=back

=head2 Information available in the extra key

=head3 Extra keys available for more than one @-command

=over

=item end_command

The C<@end> associated to the block @-command.

=item missing_argument

Set for some @-commands with line arguments and a missing argument.

=item arg_line

The string correspond to the line after the @-command 
for @-commands that have special arguments on their line,
and for C<@macro> line.

=item text_arg

The string correspond to the line after the @-command for @-commands 
that have an argument interpreted as simple text, like C<@setfilename>,
C<@end> or C<@documentencoding>.

=item index_entry

The index entry information (described in L</index_entries>
in details) is associated to @-commands that have an associated
index entry.

=item misc_args

An array holding strings, the arguments of @-commands taking simple
textual arguments as arguments, like C<@everyheadingmarks>, 
C<@frenchspacing>, C<@alias>, C<@synindex>, C<@columnfractions>.
Also filled for C<@set>, C<@clickstyle>, C<@unmacro> or C<@comment>
arguments.

=item spaces_before_argument

For @-commands with opening brace followed by spaces held in a 
C<empty_spaces_before_argument> element, a reference to those spaces.

=item spaces

For accent commands acting on one letter only, like C<@ringaccent>
appearing like

 @ringaccent A

there is a I<spaces> key which holds the spaces appearing between
the command and the argument.

=back

=head3 Extra keys specific of certain @-commands or containers

=over

=item C<@macro>

I<invalid_syntax> is set if there was an error on the C<@macro>
line.  I<arg_line> holds the line after C<@macro>.

=item C<@node>

The arguments are in the I<nodes_manuals> array. Each
of the entries is a hash with a I<node_content> key for
an array holding the corresponding content, a I<manual_content> key
if there is an associated external manual name, and a I<normalized>
key for the normalized label, built as specified in the Texinfo manual
in the B<HTML Xref> node.

An I<associated_section> key holds the tree element of the 
sectioning command that follows the node.

=item C<@part>

The next sectioning command is in I<part_associated_section>.

=item sectioning command

The node preceding the command is in I<associated_node>.
The part preceding the command is in I<associated_part>.
If the level of the document was modified by C<@raisections>
or C<@lowersections>, the differential level is in I<sections_level>.

=item C<@float>

=item C<@listoffloats>

If float has a second argument, and for C<@listoffloats>
argument there is a I<type> key which is also a hash reference, 
with two keys. I<content> is an array holding the associated
contents, I<normalized> holds the normalized float type.

I<caption> and I<shortcaption> holds the corresponding 
tree elements for float.  The C<@caption> or C<@shortcaption>
have the float tree element stored in I<float>.

=item C<@float>

=item C<@anchor>

@-commands that are targets for cross-references have a I<normalized>
key for the normalized label, built as specified in the Texinfo manual
in the B<HTML Xref> node.  There is also a I<node_content> key for
an array holding the corresponding content.

C<@anchor> also has I<region> set to the special region name if
in a special region (C<@copying>, C<@titlepage>).

=item C<@ref>

=item C<@xref>

=item C<@pxref>

=item C<@inforef>

The I<node_argument> entry holds a parsed node entry, like
the one appearing in the I<nodes_manuals> array for C<@node>.

=item C<@abbr>

=item C<@acronym>

The first argument normalized is in I<normalized>.

=item definition command

I<def_command> holds the command name, without x if it is
an x form of a definition command.
I<original_def_cmdname> is the original def command.

If it is an x form, it has I<not_after_command> set if not 
appearing after the definition command without x.

=item def_line

For each element in a def_line, the key I<def_role> holds a string
describing the meaning of the element.  It is one of
I<category>, I<name>, I<class>, I<type>, I<arg>, I<typearg>, 
I<spaces> or I<delimiter>, depending on the definition.

The I<def_parsed_hash> hash reference has these strings as keys,
and the values are the corresponding elements.

=item C<@multitable>

The key I<max_columns> holds the maximal number of columns.  If there
are prototypes on the line they are in the array associated with 
I<prototypes>.  If there is a C<@columnfractions> as argument, then the 
I<columnfractions> key is associated with the element for the
@columnfractions command.

=item C<@enumerate>

The extra key I<enumerate_specification> contains the enumerate 
argument.

=item C<@itemize>

=item C<@table>

=item C<@vtable>

=item C<@ftable>

The I<command_as_argument> extra key points to the @-command on
as argument on the @-command line.

=item paragraph

The I<indent> or I<noindent> key value is set if the corresponding 
@-commands are associated with that paragraph. 

=item C<@item> in C<@enumerate> or C<@itemize>

The I<item_number> extra key holds the number of this item.

=item C<@item> and C<@tab> in C<@multitable>

The I<cell_number> index key holds the index of the column of
the cell.

=item row

The I<row_number> index key holds the index of the row in 
the C<@multitable>.

=item C<@author>

If in a C<@titlepage>, the titlepage is in I<titlepage>, if in
C<@quotation> or C<@smallquotation>, the corresponding tree element
is in I<quotation>.

The author tree element is in the I<author> array of the C<@titlepage>
or the C<@quotation> or C<@smallquotation> it is associated with.

=item C<@ifclear>

=item C<@ifset>

The original line is in I<line>.

=item C<@end>

The textual argument is in I<command_argument>.
The corresponding @-command is in I<command>.

=item C<@documentencoding>

The argument, normalized is in I<input_encoding_name> if it is recognized.
The corresponding perl encoding name is in I<input_perl_encoding>.

=item C<@click>

In I<clickstyle> there is the current clickstyle command.

=item C<@kbd>

I<code> is set depending on the context and C<@kbdinputstyle>.

=item definfoenclose defined commands

I<begin> holds the string beginning the definfoenclose, 
I<end> holds the string ending the definfoenclose.

=item menu_entry

The I<menu_entry_description> and I<menu_entry_name> keys
are associated with the corresponding tree elements. The
I<menu_entry_node> value is a hash with information about the parsed
node entry; its keys are the same as those appearing in the
elements of the I<nodes_manuals> array for C<@node>.

=item empty_line_after_command

The corresponding command is in I<command>.

=item C<@inlinefmt>

=item C<@inlineraw>

=item C<@inlinefmtifelse>

=item C<@inlineifclear>

=item C<@inlineifset>

The first argument is in I<format>.  If an argument has been determined
as being expanded by the Parser, the index of this argument is in
I<expand_index>.  Index numbering begins at 0, but the first argument is
always the format or flag name, so, if set, it should be 1 or 2 for
C<@inlinefmtifelse>, and 1 for other commands.

=back

=head2 Other information set by the parser

The parser creates an array of nodes and stores this in the
I<nodes> key of the parser object.

Each element in the tree corresponding to a node contaning a menu
has a I<menus> key which refers to an array of references to menu
elements occuring in the node.

These are both used by the C<Texinfo::Structuring> module.



=head1 SEE ALSO

L<Texinfo manual|http://www.gnu.org/s/texinfo/manual/texinfo/>

=head1 AUTHOR

Patrice Dumas, E<lt>pertusus@free.frE<gt>

=cut
