NAME
Locale::Po4a::TeX - Convert TeX documents and derivates from/to PO
files
DESCRIPTION
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.
TRANSLATING WITH PO4A::TEX
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.
OPTIONS ACCEPTED BY THIS MODULE
These are this module's particular options:
debug
Activate debugging for some internal mechanisms of this module.
Use the source to see which parts can be debugged.
no_wrap
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.
exclude_include
Colon-separated list of files that should not be included by \input
and \include.
definitions
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
translated.
verbatim
Coma-separated list of environments which should be taken as
verbatim.
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.
INLINE CUSTOMIZATION
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
translations).
Note: In this case you don't have to specify which parameters
are translatable, but po4a must know the type and number of
parameters.
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.
WRITING DERIVATE MODULES
pre_trans
post_trans
translate
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.
get_leading_command($buffer)
This function returns:
A command name
If no command is found at the beginning of the given buffer,
this string will be empty. Only commands that can be separated
are considered. The %separated_command hash contains the list
of these commands.
A variant
This indicate if a variant is used. For example, an asterisk
(*) can be added at the end of sections command to specify that
they should not be numbered. In this case, this field will
contain "*". If there is no variant, the field is an empty
string.
An array of tuples (type of argument, argument)
The type of argument can be either '{' (for mandatory
arguments) or '[' (for optional arguments).
The remaining buffer
The rest of the buffer after the removal of this leading
command and its arguments. If no command is found, the
original buffer is not touched and returned in this field.
get_trailing_command($buffer)
The same as get_leading_command, but for commands at the end of a
buffer.
translate_buffer
Recursively translate a buffer by separating leading and trailing
commands (those which should be translated separately) from the
buffer.
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().
read
Overload Transtractor's read
read_file
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.
parse_definition_file
Subroutine for parsing a file with po4a directive (definitions for
newcommands).
parse_definition_line
Parse a definition line of the form "% po4a: ".
See the INLINE CUSTOMIZATION section for more details.
is_closed
parse
docheader
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
get_trailing_command.
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]).
STATUS OF THIS MODULE
This module needs more tests.
It was tested on a book and with the Python documentation.
TODO LIST
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.
Others
Various other points are tagged TODO in the source.
KNOWN BUGS
Various points are tagged FIXME in the source.
SEE ALSO
po4a(7), Locale::Po4a::TransTractor(3pm), Locale::Po4a::LaTeX(3pm).
AUTHORS
Nicolas Francois <nicolas.francois@centraliens.net>
COPYRIGHT AND LICENSE
Copyright 2004, 2005 by Nicolas FRANCOIS
<nicolas.francois@centraliens.net>.
This program is free software; you may redistribute it and/or modify it
under the terms of GPL (see the COPYING file).