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       Locale::Po4a::TeX - Convert TeX documents and derivates from/to PO


       The po4a (po for anything) project goal is to ease translations (and
       more interestingly, the maintenance of translations) using gettext
       tools on areas where they were not expected like documentation.

       Locale::Po4a::TeX is a module to help the translation of TeX documents
       into other [human] languages. It can also be used as a base to build
       modules for TeX-based documents.

       Users should probably use the LaTeX module, which inherite from the TeX
       module and contains the definitions of common LaTeX commands.


       This module can be used directly to handle generic TeX documents.  This
       will split your document in smaller blocks (paragraphs, verbatim
       blocks, or even smaller like titles or indexes).

       There are some options (described in the next section) that can
       customize this behavior.  If this doesn't fit to your document format
       you're encouraged to write your own module derived from this, to
       describe your format's details.  See the section "Writing derivate
       modules" below, for the process description.

       This module can also be customized by lines starting with "% po4a:" in
       the TeX file.  These customizations are described in the INLINE
       CUSTOMIZATION section.


       These are this module's particular options:

           Activate debugging for some internal mechanisms of this module.
           Use the source to see which parts can be debugged.

           Coma-separated list of environments which should not be re-wrapped.

           Note that there is a difference between verbatim and no_wrap
           environments.  There is no command and comments analysis in
           verbatim blocks.

           If this environment was not already registered, po4a will consider
           that this environment does not take any parameters.

           Colon-separated list of files that should not be included by \input
           and \include.

           The name of a file containing definitions for po4a, as defined in
           the INLINE CUSTOMIZATION section.  You can use this option if it is
           not possible to put the definitions in the document being

           Coma-separated list of environments which should be taken as

           If this environment was not already registered, po4a will consider
           that this environment does not take any parameters.

       Using these options permits to override the behaviour of the commands
       defined in the default lists.


       The TeX module can be customized with lines starting by "% po4a:".
       These lines are interpreted as commands to the parser.  The following
       commands are recognized:

       % po4a: command command1 alias command2
           Indicates that the arguments of the command1 command should be
           treated as the arguments of the command2 command.

       % po4a: command command1 parameters
           This permit to describe in detail the parameters of the command1
           command.  This information will be used to check the number of
           arguments and their types.

           You can precede the command1 command by

           an asterisk (*)
               po4a will extract this command from paragraphs (if it is
               located at the beginning or the end of a paragraph).  The
               translators will then have to translate the parameters that are
               marked as translatable.

           a plus (+)
               As for an asterisk, the command will be extracted if it appear
               at an extremity of a block, but the parameters won't be
               translated separately.  The translator will have to translate
               the command concatenated to all its parameters.  This permits
               to keep more context, and is useful for commands with small
               words in parameter, which can have multiple meanings (and

               Note: In this case you don't have to specify which parameters
               are translatable, but po4a must know the type and number of

           a minus (-)
               In this case, the command won't be extracted from any block.
               But if it appear alone on a bloc, then only the parameters
               marked as translatable will be presented to the translator.
               This is useful for font command.  These commands should
               generally not be separated from their paragraph (to keep the
               context), but there is no reason to annoy the translator with
               them if a whole string is enclosed in such a command.

           The parameters argument is a set of [] (to indicate an optional
           argument) or {} (to indicate a mandatory argument).  You can place
           an underscore (_) between these brackets to indicate that the
           parameter must be translated. For example:
            % po4a: command *chapter [_]{_}

           This indicates that the chapter command has two parameters: an
           optional (short title) and a mandatory one, which must both be
           translated.  If you want to specify that the href command has two
           mandatory parameters, that you don't want to translate the URL
           (first parameter), and that you don't want this command to be
           separated from its paragraph (which allow the translator to move
           the link in the sentence), you can use:
            % po4a: command -href {}{_}

           In this case, the information indicating which arguments must be
           translated is only used if a paragraph is only composed of this
           href command.

       % po4a: environment env parameters
           This permits to define the parameters accepted by the env
           environment.  This information is latter used to check the number
           of arguments of the \begin command, and permit to specify which one
           must be translated.  The syntax of the parameters argument is the
           same as described for the commands.  The first parameter of the
           \begin command is the name of the environment.  This parameter must
           not be specified in the list of parameters. Here are some examples:
            % po4a: environment multicols {}
            % po4a: environment equation

           As for the commands, env can be preceded by a plus (+) to indicate
           that the \begin command must be translated with all its arguments.

       % po4a: separator env "regex"
           Indicates that an environment should be split according to the
           given regular expression.

           The regular expression is delimited by quotes.  It should not
           create any backreference.  You should use (?:) if you need a group.
           It may also need some escapes.

           For example, the LaTeX module uses the "(?:&|\\\\)" regular
           expression to translate separately each cell of a table (lines are
           separated by '\\' and cells by '&').

           The notion of environment is expended to the type displayed in the
           PO file.  This can be used to split on "\\\\" in the first
           mandatory argument of the title command.  In this case, the
           environment is title{#1}.

       % po4a: verbatim environment env
           Indicate that env is a verbatim environment.  Comments and commands
           will be ignored in this environment.

           If this environment was not already registered, po4a will consider
           that this environment does not take any parameters.


           Wrapper around Transtractor's translate, with pre- and post-
           processing filters.

           Comments of a paragraph are inserted as a PO comment for the first
           translated string of this paragraph.

           This function returns:

           A command name
               If no command is found at the beginning of the given buffer,
               this string will be empty.  Only commands that can be separated
               are considered.  The %separated_command hash contains the list
               of these commands.

           A variant
               This indicate if a variant is used.  For example, an asterisk
               (*) can be added at the end of sections command to specify that
               they should not be numbered.  In this case, this field will
               contain "*".  If there is no variant, the field is an empty

           An array of tuples (type of argument, argument)
               The type of argument can be either '{' (for mandatory
               arguments) or '[' (for optional arguments).

           The remaining buffer
               The rest of the buffer after the removal of this leading
               command and its arguments.  If no command is found, the
               original buffer is not touched and returned in this field.

           The same as get_leading_command, but for commands at the end of a

           Recursively translate a buffer by separating leading and trailing
           commands (those which should be translated separately) from the

           If a function is defined in %translate_buffer_env for the current
           environment, this function will be used to translate the buffer
           instead of translate_buffer().

           Overload Transtractor's read

           Recursively read a file, appending included files which are not
           listed in the @exclude_include array.  Included files are searched
           using the kpsewhich command from the Kpathsea library.

           Except from the file inclusion part, it is a cut and paste from
           Transtractor's read.

           Subroutine for parsing a file with po4a directive (definitions for

           Parse a definition line of the form "% po4a: ".

           See the INLINE CUSTOMIZATION section for more details.


INTERNAL FUNCTIONS used to write derivated parsers

       Command and environment functions take the following arguments (in
       addition to the $self object):

       A command name
       A variant
       An array of (type, argument) tuples
       The current environment

       The first 3 arguments are extracted by get_leading_command or

       Command and environment functions return the translation of the command
       with its arguments and a new environment.

       Environment functions are called when a \begin command is found. They
       are called with the \begin command and its arguments.

       The TeX module only proposes one command function and one environment
       function: generic_command and generic_environment.

       generic_command uses the information specified by
       register_generic_command or by adding definition to the TeX file:
        % po4a: command command1 parameters

       generic_environment uses the information specified by
       register_generic_environment or by adding definition to the TeX file:
        % po4a: environment env parameters

       Both functions will only translate the parameters that were specified
       as translatable (with a '_').  generic_environment will append the name
       of the environment to the environment stack and generic_command will
       append the name of the command followed by an identifier of the
       parameter (like {#7} or [#2]).


       This module needs more tests.

       It was tested on a book and with the Python documentation.


       Automatic detection of new commands
           The TeX module could parse the newcommand arguments and try to
           guess the number of arguments, their type and whether or not they
           should be translated.

       Tranlation of the environment separator
           When \item is used as an environment separator, the item argument
           is attached to the following string.

       Some commands should be added to the environment stack
           These commands should be specified by couples.  This could allow to
           specify commands beginning or ending a verbatim environment.

           Various other points are tagged TODO in the source.


       Various points are tagged FIXME in the source.


       po4a(7), Locale::Po4a::TransTractor(3pm), Locale::Po4a::LaTeX(3pm).


        Nicolas Francois <>


       Copyright 2004, 2005 by Nicolas FRANCOIS

       This program is free software; you may redistribute it and/or modify it
       under the terms of GPL (see the COPYING file).