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|
% \iffalse meta-comment
%
%% File: l3token.dtx Copyright (C) 2005-2015 The LaTeX3 Project
%%
%% It may be distributed and/or modified under the conditions of the
%% LaTeX Project Public License (LPPL), either version 1.3c of this
%% license or (at your option) any later version. The latest version
%% of this license is in the file
%%
%% http://www.latex-project.org/lppl.txt
%%
%% This file is part of the "l3kernel bundle" (The Work in LPPL)
%% and all files in that bundle must be distributed together.
%%
%% The released version of this bundle is available from CTAN.
%%
%% -----------------------------------------------------------------------
%%
%% The development version of the bundle can be found at
%%
%% http://www.latex-project.org/svnroot/experimental/trunk/
%%
%% for those people who are interested.
%%
%%%%%%%%%%%
%% NOTE: %%
%%%%%%%%%%%
%%
%% Snapshots taken from the repository represent work in progress and may
%% not work or may contain conflicting material! We therefore ask
%% people _not_ to put them into distributions, archives, etc. without
%% prior consultation with the LaTeX3 Project.
%%
%% -----------------------------------------------------------------------
%
%<*driver>
\documentclass[full]{l3doc}
%</driver>
%<*driver|package>
\GetIdInfo$Id: l3token.dtx 6040 2015-09-23 12:41:32Z joseph $
{L3 Experimental token manipulation}
%</driver|package>
%<*driver>
\begin{document}
\DocInput{\jobname.dtx}
\end{document}
%</driver>
% \fi
%
% \title{^^A
% The \pkg{l3token} package\\ Token manipulation^^A
% \thanks{This file describes v\ExplFileVersion,
% last revised \ExplFileDate.}^^A
% }
%
% \author{^^A
% The \LaTeX3 Project\thanks
% {^^A
% E-mail:
% \href{mailto:latex-team@latex-project.org}
% {latex-team@latex-project.org}^^A
% }^^A
% }
%
% \date{Released \ExplFileDate}
%
% \maketitle
%
% \begin{documentation}
%
% This module deals with tokens. Now this is perhaps not the most
% precise description so let's try with a better description: When
% programming in \TeX{}, it is often desirable to know just what a
% certain token is: is it a control sequence or something
% else. Similarly one often needs to know if a control sequence is
% expandable or not, a macro or a primitive, how many arguments it
% takes etc. Another thing of great importance (especially when it
% comes to document commands) is looking ahead in the token stream to
% see if a certain character is present and maybe even remove it or
% disregard other tokens while scanning. This module provides
% functions for both and as such will have two primary function
% categories: |\token_| for anything that deals with tokens and
% |\peek_| for looking ahead in the token stream.
%
% Most of the time we will be using the term \enquote{token} but most of the
% time the function we're describing can equally well by used on a
% control sequence as such one is one token as well.
%
% We shall refer to list of tokens as |tlist|s and such lists
% represented by a single control sequence is a \enquote{token list variable}
% |tl var|. Functions for these two types are found in the \textsf{l3tl}
% module.
%
% \section{All possible tokens}
%
% Let us start by reviewing every case that a given token can fall into.
% It is very important to distinguish two aspects of a token: its meaning,
% and what it looks like.
%
% For instance, \cs{if:w}, \cs{if_charcode:w}, and \cs{tex_if:D} are
% three names for the same internal operation of \TeX{}, namely the primitive
% testing the next two characters for equality of their character code.
% They behave identically in many situations. However, \TeX{}
% distinguishes them when searching for a delimited argument. Namely, the
% example function |\show_until_if:w| defined below will take everything
% until \cs{if:w} as an argument, despite the presence of other copies of
% \cs{if:w} under different names.
% \begin{verbatim}
% \cs_new:Npn \show_until_if:w #1 \if:w { \tl_show:n {#1} }
% \show_until_if:w \tex_if:D \if_charcode:w \if:w
% \end{verbatim}
%
% \section{Character tokens}
%
% \begin{function}[updated = 2015-08-09]
% {
% \char_set_catcode_escape:N ,
% \char_set_catcode_group_begin:N ,
% \char_set_catcode_group_end:N ,
% \char_set_catcode_math_toggle:N ,
% \char_set_catcode_alignment:N ,
% \char_set_catcode_end_line:N ,
% \char_set_catcode_parameter:N ,
% \char_set_catcode_math_superscript:N ,
% \char_set_catcode_math_subscript:N ,
% \char_set_catcode_ignore:N ,
% \char_set_catcode_space:N ,
% \char_set_catcode_letter:N ,
% \char_set_catcode_other:N ,
% \char_set_catcode_active:N ,
% \char_set_catcode_comment:N ,
% \char_set_catcode_invalid:N
% }
% \begin{syntax}
% \cs{char_set_catcode_letter:N} \meta{character}
% \end{syntax}
% Sets the category code of the \meta{character} to that indicated in
% the function name. Depending on the current category code of the
% \meta{token} the escape token may also be needed:
% \begin{verbatim}
% \char_set_catcode_other:N \%
% \end{verbatim}
% The assignment is local. These commands update
% \cs{l_char_special_seq} as appropriate by adding or removing the
% \meta{character}, and in package mode they also update
% \tn{dospecials} (plain \TeX{} and \LaTeXe{}) and \cs{@sanitize}
% (\LaTeXe{} only). The \cs{char_set_catcode_active:N} command
% also adds the active character to \cs{l_char_active_seq}.
% \end{function}
%
% \begin{function}[updated = 2015-08-09]
% {
% \char_set_catcode_escape:n ,
% \char_set_catcode_group_begin:n ,
% \char_set_catcode_group_end:n ,
% \char_set_catcode_math_toggle:n ,
% \char_set_catcode_alignment:n ,
% \char_set_catcode_end_line:n ,
% \char_set_catcode_parameter:n ,
% \char_set_catcode_math_superscript:n ,
% \char_set_catcode_math_subscript:n ,
% \char_set_catcode_ignore:n ,
% \char_set_catcode_space:n ,
% \char_set_catcode_letter:n ,
% \char_set_catcode_other:n ,
% \char_set_catcode_active:n ,
% \char_set_catcode_comment:n ,
% \char_set_catcode_invalid:n
% }
% \begin{syntax}
% \cs{char_set_catcode_letter:n} \Arg{integer expression}
% \end{syntax}
% Sets the category code of the \meta{character} which has character
% code as given by the \meta{integer expression}. This version can be
% used to set up characters which cannot otherwise be given
% (\emph{cf.}~the \texttt{N}-type variants). The assignment is local.
% These commands update \cs{l_char_special_seq} as appropriate by
% adding or removing the \meta{character}, and in package mode they
% also update \tn{dospecials} (plain \TeX{} and \LaTeXe{}) and
% \cs{@sanitize} (\LaTeXe{} only). The \cs{char_set_catcode_active:n}
% command also adds the active character to \cs{l_char_active_seq}.
% \end{function}
%
% \begin{function}[updated = 2015-08-09]{\char_set_catcode:nn}
% \begin{syntax}
% \cs{char_set_catcode:nn} \Arg{intexpr_1} \Arg{intexpr_2}
% \end{syntax}
% These functions set the category code of the \meta{character} which
% has character code as given by the \meta{integer expression}.
% The first \meta{integer expression}
% is the character code and the second is the category code to apply.
% The setting applies within the current \TeX{} group. In general, the
% symbolic functions \cs{char_set_catcode_\meta{type}} should be preferred,
% but there are cases where these lower-level functions may be useful.
% This command updates \cs{l_char_special_seq} as appropriate by
% adding or removing the \meta{character}, and in package mode it
% also updates \tn{dospecials} (plain \TeX{} and \LaTeXe{}) and
% \cs{@sanitize} (\LaTeXe{} only).
% If the category code is $13$ (active), the active character is
% added to \cs{l_char_active_seq}.
% \end{function}
%
% \begin{function}[EXP]{\char_value_catcode:n}
% \begin{syntax}
% \cs{char_value_catcode:n} \Arg{integer expression}
% \end{syntax}
% Expands to the current category code of the \meta{character} with
% character code given by the
% \meta{integer expression}.
% \end{function}
%
% \begin{function}{\char_show_value_catcode:n}
% \begin{syntax}
% \cs{char_show_value_catcode:n} \Arg{integer expression}
% \end{syntax}
% Displays the current category code of the \meta{character} with
% character code given by the \meta{integer expression} on the
% terminal.
% \end{function}
%
% \begin{function}[updated = 2015-08-06]{\char_set_lccode:nn}
% \begin{syntax}
% \cs{char_set_lcode:nn} \Arg{intexpr_1} \Arg{intexpr_2}
% \end{syntax}
% Sets up the behaviour of the \meta{character} when
% found inside \cs{tl_to_lowercase:n}, such that \meta{character_1}
% will be converted into \meta{character_2}. The two \meta{characters}
% may be specified using an \meta{integer expression} for the character code
% concerned. This may include the \TeX{} |`|\meta{character}
% method for converting a single character into its character
% code:
% \begin{verbatim}
% \char_set_lccode:nn { `\A } { `\a } % Standard behaviour
% \char_set_lccode:nn { `\A } { `\A + 32 }
% \char_set_lccode:nn { 50 } { 60 }
% \end{verbatim}
% The setting applies within the current \TeX{} group.
% \end{function}
%
% \begin{function}[EXP]{\char_value_lccode:n}
% \begin{syntax}
% \cs{char_value_lccode:n} \Arg{integer expression}
% \end{syntax}
% Expands to the current lower case code of the \meta{character} with
% character code given by the
% \meta{integer expression}.
% \end{function}
%
% \begin{function}{\char_show_value_lccode:n}
% \begin{syntax}
% \cs{char_show_value_lccode:n} \Arg{integer expression}
% \end{syntax}
% Displays the current lower case code of the \meta{character} with
% character code given by the \meta{integer expression} on the
% terminal.
% \end{function}
%
% \begin{function}[updated = 2015-08-06]{\char_set_uccode:nn}
% \begin{syntax}
% \cs{char_set_uccode:nn} \Arg{intexpr_1} \Arg{intexpr_2}
% \end{syntax}
% Sets up the behaviour of the \meta{character} when
% found inside \cs{tl_to_uppercase:n}, such that \meta{character_1}
% will be converted into \meta{character_2}. The two \meta{characters}
% may be specified using an \meta{integer expression} for the character code
% concerned. This may include the \TeX{} |`|\meta{character}
% method for converting a single character into its character
% code:
% \begin{verbatim}
% \char_set_uccode:nn { `\a } { `\A } % Standard behaviour
% \char_set_uccode:nn { `\A } { `\A - 32 }
% \char_set_uccode:nn { 60 } { 50 }
% \end{verbatim}
% The setting applies within the current \TeX{} group.
% \end{function}
%
% \begin{function}[EXP]{\char_value_uccode:n}
% \begin{syntax}
% \cs{char_value_uccode:n} \Arg{integer expression}
% \end{syntax}
% Expands to the current upper case code of the \meta{character} with
% character code given by the
% \meta{integer expression}.
% \end{function}
%
% \begin{function}{\char_show_value_uccode:n}
% \begin{syntax}
% \cs{char_show_value_uccode:n} \Arg{integer expression}
% \end{syntax}
% Displays the current upper case code of the \meta{character} with
% character code given by the \meta{integer expression} on the
% terminal.
% \end{function}
%
% \begin{function}[updated = 2015-08-06]{\char_set_mathcode:nn}
% \begin{syntax}
% \cs{char_set_mathcode:nn} \Arg{intexpr_1} \Arg{intexpr_2}
% \end{syntax}
% This function sets up the math code of \meta{character}.
% The \meta{character} is specified as
% an \meta{integer expression} which will be used as the character
% code of the relevant character. The setting applies within the
% current \TeX{} group.
% \end{function}
%
% \begin{function}[EXP]{\char_value_mathcode:n}
% \begin{syntax}
% \cs{char_value_mathcode:n} \Arg{integer expression}
% \end{syntax}
% Expands to the current math code of the \meta{character} with
% character code given by the
% \meta{integer expression}.
% \end{function}
%
% \begin{function}{\char_show_value_mathcode:n}
% \begin{syntax}
% \cs{char_show_value_mathcode:n} \Arg{integer expression}
% \end{syntax}
% Displays the current math code of the \meta{character} with
% character code given by the \meta{integer expression} on the
% terminal.
% \end{function}
%
% \begin{function}[updated = 2015-08-06]{\char_set_sfcode:nn}
% \begin{syntax}
% \cs{char_set_sfcode:nn} \Arg{intexpr_1} \Arg{intexpr_2}
% \end{syntax}
% This function sets up the space factor for the \meta{character}.
% The \meta{character} is specified as
% an \meta{integer expression} which will be used as the character
% code of the relevant character. The setting applies within the
% current \TeX{} group.
% \end{function}
%
% \begin{function}[EXP]{\char_value_sfcode:n}
% \begin{syntax}
% \cs{char_value_sfcode:n} \Arg{integer expression}
% \end{syntax}
% Expands to the current space factor for the \meta{character} with
% character code given by the
% \meta{integer expression}.
% \end{function}
%
% \begin{function}{\char_show_value_sfcode:n}
% \begin{syntax}
% \cs{char_show_value_sfcode:n} \Arg{integer expression}
% \end{syntax}
% Displays the current space factor for the \meta{character} with
% character code given by the \meta{integer expression} on the
% terminal.
% \end{function}
%
% \begin{variable}[added = 2012-01-23, updated = 2015-08-09]{\l_char_active_seq}
% Used to track which tokens may require special handling at the document
% level as they are (or have been at some point)
% of category \meta{active} (catcode~$13$). Each entry in
% the sequence consists of a single active character. Active tokens should be
% added to the sequence when they are defined for general document use.
% This sequence is automatically updated by \cs{char_set_catcode:nn} and
% more specific functions.
% \end{variable}
%
% \begin{variable}[added = 2012-01-23, updated = 2015-08-09]{\l_char_special_seq}
% Used to track which tokens will require special handling when working with
% verbatim-like material at the document level as they are not of categories
% \meta{letter} (catcode~$11$) or \meta{other} (catcode~$12$). Each entry in
% the sequence consists of a single escaped token, for example |\\| for the
% backslash or |\{| for an opening brace.^^A \}
% Escaped tokens should be added to the sequence when they are defined for
% general document use.
% This sequence is automatically updated by \cs{char_set_catcode:nn} and
% more specific functions.
% \end{variable}
%
% \section{Generic tokens}
%
% \begin{function}{\token_new:Nn}
% \begin{syntax}
% \cs{token_new:Nn} \meta{token_1} \Arg{token_2}
% \end{syntax}
% Defines \meta{token_1} to globally be a snapshot of \meta{token_2}.
% This will be an implicit representation of \meta{token_2}.
% \end{function}
%
% ^^A Because it's late I can't figure out a better way to handle this:
% \ExplSyntaxOn
% \cs_set_eq:NN \c_alignment_token @
% \cs_set_eq:NN \c_parameter_token @
% \ExplSyntaxOff
% \begin{variable}
% {
% \c_group_begin_token,
% \c_group_end_token,
% \c_math_toggle_token,
% \c_alignment_token,
% \c_parameter_token,
% \c_math_superscript_token,
% \c_math_subscript_token,
% \c_space_token
% }
% These are implicit tokens which have the category code described
% by their name. They are used internally for test purposes but
% are also available to the programmer for other uses.
% \end{variable}
% \ExplSyntaxOn
% \cs_set_eq:NN \c_alignment_token &
% \cs_set_eq:NN \c_parameter_token #
% \ExplSyntaxOff
%
% \begin{variable}
% {
% \c_catcode_letter_token,
% \c_catcode_other_token
% }
% These are implicit tokens which have the category code described
% by their name. They are used internally for test purposes and should
% not be used other than for category code tests.
% \end{variable}
%
% \begin{variable}{\c_catcode_active_tl}
% A token list containing an active token. This is used internally
% for test purposes and should not be used other than in
% appropriately-constructed category code tests.
% \end{variable}
%
% \section{Converting tokens}
%
% \begin{function}[EXP]{\token_to_meaning:N, \token_to_meaning:c}
% \begin{syntax}
% \cs{token_to_meaning:N} \meta{token}
% \end{syntax}
% Inserts the current meaning of the \meta{token} into the input
% stream as a series of characters of category code $12$ (other).
% This will be the primitive \TeX{} description of the \meta{token},
% thus for example both functions defined by \cs{cs_set_nopar:Npn}
% and token list variables defined using \cs{tl_new:N} will be described
% as |macro|s.
% \begin{texnote}
% This is the \TeX{} primitive \tn{meaning}.
% \end{texnote}
% \end{function}
%
% \begin{function}[EXP]{\token_to_str:N, \token_to_str:c}
% \begin{syntax}
% \cs{token_to_str:N} \meta{token}
% \end{syntax}
% Converts the given \meta{token} into a series of characters with
% category code $12$ (other). The current escape character will be
% the first character in the sequence, although this will also have
% category code $12$ (the escape character is part of the
% \meta{token}). This function requires only a single expansion.
% \begin{texnote}
% \cs{token_to_str:N} is the \TeX{} primitive \tn{string} renamed.
% \end{texnote}
% \end{function}
%
% \section{Token conditionals}
%
% \begin{function}[EXP,pTF]{\token_if_group_begin:N}
% \begin{syntax}
% \cs{token_if_group_begin_p:N} \meta{token} \\
% \cs{token_if_group_begin:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if \meta{token} has the category code of a begin group token
% (|{| when normal \TeX{} category codes are in ^^A }
% force).
% Note that an explicit begin group token cannot be tested in this way,
% as it is not a valid \texttt{N}-type argument.
% \end{function}
%
% \begin{function}[EXP,pTF]{\token_if_group_end:N}
% \begin{syntax}
% \cs{token_if_group_end_p:N} \meta{token} \\
% \cs{token_if_group_end:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if \meta{token} has the category code of an end group token
% (^^A {
% |}| when normal \TeX{} category codes are in force).
% Note that an explicit end group token cannot be tested in this way,
% as it is not a valid \texttt{N}-type argument.
% \end{function}
%
% \begin{function}[EXP,pTF]{\token_if_math_toggle:N}
% \begin{syntax}
% \cs{token_if_math_toggle_p:N} \meta{token} \\
% \cs{token_if_math_toggle:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if \meta{token} has the category code of a math shift token
% (|$| when normal \TeX{} category codes are in force).
% \end{function}
%
% \begin{function}[EXP,pTF]{\token_if_alignment:N}
% \begin{syntax}
% \cs{token_if_alignment_p:N} \meta{token} \\
% \cs{token_if_alignment:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if \meta{token} has the category code of an alignment token
% (|&| when normal \TeX{} category codes are in force).
% \end{function}
%
% \begin{function}[EXP,pTF]{\token_if_parameter:N}
% \begin{syntax}
% \cs{token_if_parameter_p:N} \meta{token} \\
% \cs{token_if_alignment:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if \meta{token} has the category code of a macro parameter token
% (|#| when normal \TeX{} category codes are in force).
% \end{function}
%
% \begin{function}[EXP,pTF]{\token_if_math_superscript:N}
% \begin{syntax}
% \cs{token_if_math_superscript_p:N} \meta{token} \\
% \cs{token_if_math_superscript:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if \meta{token} has the category code of a superscript token
% (|^| when normal \TeX{} category codes are in force).
% \end{function}
%
% \begin{function}[EXP,pTF]{\token_if_math_subscript:N}
% \begin{syntax}
% \cs{token_if_math_subscript_p:N} \meta{token} \\
% \cs{token_if_math_subscript:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if \meta{token} has the category code of a subscript token
% (|_| when normal \TeX{} category codes are in force).
% \end{function}
%
% \begin{function}[EXP,pTF]{\token_if_space:N}
% \begin{syntax}
% \cs{token_if_space_p:N} \meta{token} \\
% \cs{token_if_space:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if \meta{token} has the category code of a space token.
% Note that an explicit space token with character code $32$ cannot
% be tested in this way, as it is not a valid \texttt{N}-type argument.
% \end{function}
%
% \begin{function}[EXP,pTF]{\token_if_letter:N}
% \begin{syntax}
% \cs{token_if_letter_p:N} \meta{token} \\
% \cs{token_if_letter:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if \meta{token} has the category code of a letter token.
% \end{function}
%
% \begin{function}[EXP,pTF]{\token_if_other:N}
% \begin{syntax}
% \cs{token_if_other_p:N} \meta{token} \\
% \cs{token_if_other:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if \meta{token} has the category code of an \enquote{other}
% token.
% \end{function}
%
% \begin{function}[EXP,pTF]{\token_if_active:N}
% \begin{syntax}
% \cs{token_if_active_p:N} \meta{token} \\
% \cs{token_if_active:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if \meta{token} has the category code of an active character.
% \end{function}
%
% \begin{function}[EXP,pTF]{\token_if_eq_catcode:NN}
% \begin{syntax}
% \cs{token_if_eq_catcode_p:NN} \meta{token_1} \meta{token_2} \\
% \cs{token_if_eq_catcode:NNTF} \meta{token_1} \meta{token_2} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the two \meta{tokens} have the same category code.
% \end{function}
%
% \begin{function}[EXP,pTF]{\token_if_eq_charcode:NN}
% \begin{syntax}
% \cs{token_if_eq_charcode_p:NN} \meta{token_1} \meta{token_2} \\
% \cs{token_if_eq_charcode:NNTF} \meta{token_1} \meta{token_2} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the two \meta{tokens} have the same character code.
% \end{function}
%
% \begin{function}[EXP,pTF]{\token_if_eq_meaning:NN}
% \begin{syntax}
% \cs{token_if_eq_meaning_p:NN} \meta{token_1} \meta{token_2} \\
% \cs{token_if_eq_meaning:NNTF} \meta{token_1} \meta{token_2} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the two \meta{tokens} have the same meaning when expanded.
% \end{function}
%
% \begin{function}[updated = 2011-05-23, EXP,pTF]{\token_if_macro:N}
% \begin{syntax}
% \cs{token_if_macro_p:N} \meta{token} \\
% \cs{token_if_macro:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the \meta{token} is a \TeX{} macro.
% \end{function}
%
% \begin{function}[EXP,pTF]{\token_if_cs:N}
% \begin{syntax}
% \cs{token_if_cs_p:N} \meta{token} \\
% \cs{token_if_cs:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the \meta{token} is a control sequence.
% \end{function}
%
% \begin{function}[EXP,pTF]{\token_if_expandable:N}
% \begin{syntax}
% \cs{token_if_expandable_p:N} \meta{token} \\
% \cs{token_if_expandable:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the \meta{token} is expandable. This test returns \meta{false}
% for an undefined token.
% \end{function}
%
% \begin{function}[EXP,pTF, updated=2012-01-20]{\token_if_long_macro:N}
% \begin{syntax}
% \cs{token_if_long_macro_p:N} \meta{token} \\
% \cs{token_if_long_macro:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the \meta{token} is a long macro.
% \end{function}
%
% \begin{function}[EXP,pTF, updated=2012-01-20]{\token_if_protected_macro:N}
% \begin{syntax}
% \cs{token_if_protected_macro_p:N} \meta{token} \\
% \cs{token_if_protected_macro:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the \meta{token} is a protected macro: a macro which
% is both protected and long will return logical \texttt{false}.
% \end{function}
%
% \begin{function}[EXP,pTF, updated=2012-01-20]{\token_if_protected_long_macro:N}
% \begin{syntax}
% \cs{token_if_protected_long_macro_p:N} \meta{token} \\
% \cs{token_if_protected_long_macro:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the \meta{token} is a protected long macro.
% \end{function}
%
% \begin{function}[EXP,pTF, updated=2012-01-20]{\token_if_chardef:N}
% \begin{syntax}
% \cs{token_if_chardef_p:N} \meta{token} \\
% \cs{token_if_chardef:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the \meta{token} is defined to be a chardef.
% \begin{texnote}
% Booleans, boxes and small integer constants are implemented as
% chardefs.
% \end{texnote}
% \end{function}
%
% \begin{function}[EXP,pTF, updated=2012-01-20]{\token_if_mathchardef:N}
% \begin{syntax}
% \cs{token_if_mathchardef_p:N} \meta{token} \\
% \cs{token_if_mathchardef:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the \meta{token} is defined to be a mathchardef.
% \end{function}
%
% \begin{function}[EXP,pTF, updated=2012-01-20]{\token_if_dim_register:N}
% \begin{syntax}
% \cs{token_if_dim_register_p:N} \meta{token} \\
% \cs{token_if_dim_register:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the \meta{token} is defined to be a dimension register.
% \end{function}
%
% \begin{function}[EXP,pTF, updated=2012-01-20]{\token_if_int_register:N}
% \begin{syntax}
% \cs{token_if_int_register_p:N} \meta{token} \\
% \cs{token_if_int_register:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the \meta{token} is defined to be a integer register.
% \begin{texnote}
% Constant integers may be implemented as integer registers,
% chardefs, or mathchardefs depending on their value.
% \end{texnote}
% \end{function}
%
% \begin{function}[EXP,pTF, added=2012-02-15]{\token_if_muskip_register:N}
% \begin{syntax}
% \cs{token_if_muskip_register_p:N} \meta{token} \\
% \cs{token_if_muskip_register:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the \meta{token} is defined to be a muskip register.
% \end{function}
%
% \begin{function}[EXP,pTF, updated=2012-01-20]{\token_if_skip_register:N}
% \begin{syntax}
% \cs{token_if_skip_register_p:N} \meta{token} \\
% \cs{token_if_skip_register:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the \meta{token} is defined to be a skip register.
% \end{function}
%
% \begin{function}[EXP,pTF, updated=2012-01-20]{\token_if_toks_register:N}
% \begin{syntax}
% \cs{token_if_toks_register_p:N} \meta{token} \\
% \cs{token_if_toks_register:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the \meta{token} is defined to be a toks register
% (not used by\LaTeX3).
% \end{function}
%
% \begin{function}[updated = 2011-05-23, EXP,pTF]{\token_if_primitive:N}
% \begin{syntax}
% \cs{token_if_primitive_p:N} \meta{token} \\
% \cs{token_if_primitive:NTF} \meta{token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the \meta{token} is an engine primitive.
% \end{function}
%
% \section{Peeking ahead at the next token}
%
% There is often a need to look ahead at the next token in the input
% stream while leaving it in place. This is handled using the
% \enquote{peek} functions. The generic \cs{peek_after:Nw} is
% provided along with a family of predefined tests for common cases.
% As peeking ahead does \emph{not} skip spaces the predefined tests
% include both a space-respecting and space-skipping version.
%
% \begin{function}{\peek_after:Nw}
% \begin{syntax}
% \cs{peek_after:Nw} \meta{function} \meta{token}
% \end{syntax}
% Locally sets the test variable \cs{l_peek_token} equal to \meta{token}
% (as an implicit token, \emph{not} as a token list), and then
% expands the \meta{function}. The \meta{token} will remain in
% the input stream as the next item after the \meta{function}.
% The \meta{token} here may be \verb*| |, |{| or |}| (assuming
% normal \TeX{} category codes), \emph{i.e.}~it is not necessarily the
% next argument which would be grabbed by a normal function.
% \end{function}
%
% \begin{function}{\peek_gafter:Nw}
% \begin{syntax}
% \cs{peek_gafter:Nw} \meta{function} \meta{token}
% \end{syntax}
% Globally sets the test variable \cs{g_peek_token} equal to \meta{token}
% (as an implicit token, \emph{not} as a token list), and then
% expands the \meta{function}. The \meta{token} will remain in
% the input stream as the next item after the \meta{function}.
% The \meta{token} here may be \verb*| |, |{| or |}| (assuming
% normal \TeX{} category codes), \emph{i.e.}~it is not necessarily the
% next argument which would be grabbed by a normal function.
% \end{function}
%
% \begin{variable}{\l_peek_token}
% Token set by \cs{peek_after:Nw} and available for testing
% as described above.
% \end{variable}
%
% \begin{variable}{\g_peek_token}
% Token set by \cs{peek_gafter:Nw} and available for testing
% as described above.
% \end{variable}
%
% \begin{function}[updated = 2012-12-20, TF]{\peek_catcode:N}
% \begin{syntax}
% \cs{peek_catcode:NTF} \meta{test token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the next \meta{token} in the input stream has the same
% category code as the \meta{test token} (as defined by the test
% \cs{token_if_eq_catcode:NNTF}). Spaces are respected by the test
% and the \meta{token} will be left in the input stream after
% the \meta{true code} or \meta{false code} (as appropriate to the
% result of the test).
% \end{function}
%
% \begin{function}[updated = 2012-12-20, TF]{\peek_catcode_ignore_spaces:N}
% \begin{syntax}
% \cs{peek_catcode_ignore_spaces:NTF} \meta{test token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the next non-space \meta{token} in the input stream has the
% same category code as the \meta{test token} (as defined by the test
% \cs{token_if_eq_catcode:NNTF}). Explicit and implicit space tokens
% (with character code 32 and category code 10) are ignored and
% removed by the test and the \meta{token} will be left in the input
% stream after the \meta{true code} or \meta{false code} (as
% appropriate to the result of the test).
% \end{function}
%
% \begin{function}[updated = 2012-12-20, TF]{\peek_catcode_remove:N}
% \begin{syntax}
% \cs{peek_catcode_remove:NTF} \meta{test token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the next \meta{token} in the input stream has the same
% category code as the \meta{test token} (as defined by the test
% \cs{token_if_eq_catcode:NNTF}). Spaces are respected by the test
% and the \meta{token} will be removed from the input stream if the
% test is true. The function will then place either the
% \meta{true code} or \meta{false code} in the input stream (as
% appropriate to the result of the test).
% \end{function}
%
% \begin{function}[updated = 2012-12-20, TF]
% {\peek_catcode_remove_ignore_spaces:N}
% \begin{syntax}
% \cs{peek_catcode_remove_ignore_spaces:NTF} \meta{test token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the next non-space \meta{token} in the input stream has the
% same category code as the \meta{test token} (as defined by the test
% \cs{token_if_eq_catcode:NNTF}). Explicit and implicit space tokens
% (with character code 32 and category code 10) are ignored and
% removed by the test and the \meta{token} will be removed from the
% input stream if the test is true. The function will then place
% either the \meta{true code} or \meta{false code} in the input stream
% (as appropriate to the result of the test).
% \end{function}
%
% \begin{function}[updated = 2012-12-20, TF]{\peek_charcode:N}
% \begin{syntax}
% \cs{peek_charcode:NTF} \meta{test token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the next \meta{token} in the input stream has the same
% character code as the \meta{test token} (as defined by the test
% \cs{token_if_eq_charcode:NNTF}). Spaces are respected by the test
% and the \meta{token} will be left in the input stream after
% the \meta{true code} or \meta{false code} (as appropriate to the
% result of the test).
% \end{function}
%
% \begin{function}[updated = 2012-12-20, TF]{\peek_charcode_ignore_spaces:N}
% \begin{syntax}
% \cs{peek_charcode_ignore_spaces:NTF} \meta{test token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the next non-space \meta{token} in the input stream has the
% same character code as the \meta{test token} (as defined by the test
% \cs{token_if_eq_charcode:NNTF}). Explicit and implicit space tokens
% (with character code 32 and category code 10) are ignored and removed by
% the test and the \meta{token} will be left in the input stream after
% the \meta{true code} or \meta{false code} (as appropriate to the
% result of the test).
% \end{function}
%
% \begin{function}[updated = 2012-12-20, TF]{\peek_charcode_remove:N}
% \begin{syntax}
% \cs{peek_charcode_remove:NTF} \meta{test token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the next \meta{token} in the input stream has the same
% character code as the \meta{test token} (as defined by the test
% \cs{token_if_eq_charcode:NNTF}). Spaces are respected by the test
% and the \meta{token} will be removed from the input stream if the
% test is true. The function will then place either the
% \meta{true code} or \meta{false code} in the input stream (as
% appropriate to the result of the test).
% \end{function}
%
% \begin{function}[updated = 2012-12-20, TF]
% {\peek_charcode_remove_ignore_spaces:N}
% \begin{syntax}
% \cs{peek_charcode_remove_ignore_spaces:NTF} \meta{test token}
% ~~\Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the next non-space \meta{token} in the input stream has the
% same character code as the \meta{test token} (as defined by the test
% \cs{token_if_eq_charcode:NNTF}). Explicit and implicit space tokens
% (with character code 32 and category code 10) are ignored and
% removed by the test and the \meta{token} will be removed from the
% input stream if the test is true. The function will then place
% either the \meta{true code} or \meta{false code} in the input stream
% (as appropriate to the result of the test).
% \end{function}
%
% \begin{function}[updated = 2011-07-02, TF]{\peek_meaning:N}
% \begin{syntax}
% \cs{peek_meaning:NTF} \meta{test token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the next \meta{token} in the input stream has the same
% meaning as the \meta{test token} (as defined by the test
% \cs{token_if_eq_meaning:NNTF}). Spaces are respected by the test
% and the \meta{token} will be left in the input stream after
% the \meta{true code} or \meta{false code} (as appropriate to the
% result of the test).
% \end{function}
%
% \begin{function}[updated = 2012-12-05, TF]{\peek_meaning_ignore_spaces:N}
% \begin{syntax}
% \cs{peek_meaning_ignore_spaces:NTF} \meta{test token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the next non-space \meta{token} in the input stream has the
% same meaning as the \meta{test token} (as defined by the test
% \cs{token_if_eq_meaning:NNTF}). Explicit and implicit space tokens
% (with character code 32 and category code 10) are ignored and
% removed by the test and the \meta{token} will be left in the input
% stream after the \meta{true code} or \meta{false code} (as
% appropriate to the result of the test).
% \end{function}
%
% \begin{function}[updated = 2011-07-02, TF]{\peek_meaning_remove:N}
% \begin{syntax}
% \cs{peek_meaning_remove:NTF} \meta{test token} \Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the next \meta{token} in the input stream has the same
% meaning as the \meta{test token} (as defined by the test
% \cs{token_if_eq_meaning:NNTF}). Spaces are respected by the test
% and the \meta{token} will be removed from the input stream if the
% test is true. The function will then place either the
% \meta{true code} or \meta{false code} in the input stream (as
% appropriate to the result of the test).
% \end{function}
%
% \begin{function}[updated = 2012-12-05, TF]
% {\peek_meaning_remove_ignore_spaces:N}
% \begin{syntax}
% \cs{peek_meaning_remove_ignore_spaces:NTF} \meta{test token}
% ~~\Arg{true code} \Arg{false code}
% \end{syntax}
% Tests if the next non-space \meta{token} in the input stream has the
% same meaning as the \meta{test token} (as defined by the test
% \cs{token_if_eq_meaning:NNTF}). Explicit and implicit space tokens
% (with character code 32 and category code 10) are ignored and
% removed by the test and the \meta{token} will be removed from the
% input stream if the test is true. The function will then place
% either the \meta{true code} or \meta{false code} in the input stream
% (as appropriate to the result of the test).
% \end{function}
%
% \section{Decomposing a macro definition}
%
% These functions decompose \TeX{} macros into their constituent
% parts: if the \meta{token} passed is not a macro then no decomposition
% can occur. In the later case, all three functions leave \cs{scan_stop:}
% in the input stream.
%
% \begin{function}[EXP]{\token_get_arg_spec:N}
% \begin{syntax}
% \cs{token_get_arg_spec:N} \meta{token}
% \end{syntax}
% If the \meta{token} is a macro, this function will leave
% the primitive \TeX{} argument specification in input stream as
% a string of tokens of category code $12$ (with spaces having category
% code $10$). Thus for example for a token \cs{next} defined by
% \begin{verbatim}
% \cs_set:Npn \next #1#2 { x #1 y #2 }
% \end{verbatim}
% will leave |#1#2| in the input stream. If the \meta{token} is
% not a macro then \cs{scan_stop:} will be left in the input stream.
% \begin{texnote}
% If the arg~spec. contains the string |->|, then the |spec| function
% will produce incorrect results.
% \end{texnote}
% \end{function}
%
% \begin{function}[EXP]{\token_get_replacement_spec:N}
% \begin{syntax}
% \cs{token_get_replacement_spec:N} \meta{token}
% \end{syntax}
% If the \meta{token} is a macro, this function will leave
% the replacement text in input stream as
% a string of tokens of category code $12$ (with spaces having category
% code $10$). Thus for example for a token \cs{next} defined by
% \begin{verbatim}
% \cs_set:Npn \next #1#2 { x #1~y #2 }
% \end{verbatim}
% will leave \verb|x#1 y#2| in the input stream. If the \meta{token} is
% not a macro then \cs{scan_stop:} will be left in the input stream.
% \begin{texnote}
% If the arg~spec. contains the string |->|, then the |spec| function
% will produce incorrect results.
% \end{texnote}
% \end{function}
%
% \begin{function}[EXP]{\token_get_prefix_spec:N}
% \begin{syntax}
% \cs{token_get_prefix_spec:N} \meta{token}
% \end{syntax}
% If the \meta{token} is a macro, this function will leave
% the \TeX{} prefixes applicable in input stream as
% a string of tokens of category code $12$ (with spaces having category
% code $10$). Thus for example for a token \cs{next} defined by
% \begin{verbatim}
% \cs_set:Npn \next #1#2 { x #1~y #2 }
% \end{verbatim}
% will leave |\long| in the input stream. If the \meta{token} is
% not a macro then \cs{scan_stop:} will be left in the input stream
% \end{function}
%
% \end{documentation}
%
% \begin{implementation}
%
% \section{\pkg{l3token} implementation}
%
% \begin{macrocode}
%<*initex|package>
% \end{macrocode}
%
% \begin{macrocode}
%<@@=char>
% \end{macrocode}
%
% \subsection{Character tokens}
%
% \begin{macro}{\char_set_catcode:nn}
% \begin{macro}{\char_value_catcode:n}
% \begin{macro}{\char_show_value_catcode:n}
% \begin{macro}[aux]
% {
% \@@_set_catcode:Nn,
% \@@_set_catcode:NnNNN,
% \@@_set_catcode:NNN,
% }
% Category code changes. Besides setting the catcode using
% \cs{tex_catcode:D}, this function keeps up to date the sequences
% \cs{l_char_active_seq}, \cs{l_char_special_seq}, and in package
% mode \tn{dospecials} (for plain \TeX{} and \LaTeXe{}) and
% \tn{@sanitize} (\LaTeXe{} only) as well. The first list contains
% active characters, and the other three contain a single-character
% control sequence. These are constructed from the given character
% code |#1| using the \tn{lowercase} primitive. In package mode
% there are difficulties because |\+| and the active |^^L| are
% \tn{outer} macros. This pushes us to only construct the
% single-character control sequence and the active character with
% character code |#1| if they are necessary for the update. As a
% start, construct an \enquote{other} (catcode~$12$) with character
% code |#1|. The second part of the \texttt{:Nn} auxiliary takes
% care of \cs{l_char_active_seq}: if the new catcode is $13$
% (active), then the active character is constructed through
% \tn{lowercase} and added to the sequence unless it is already in
% there. The first part is more intricate and distinguishes the
% case where the original catcode is special (different from letter
% or other, since for \eTeX{}'s \tn{numexpr}, $11/2=12/2=6$) or not.
% If it the catcode was special, the single-character control
% sequence may need to be removed from the token lists and sequence,
% otherwise it may need to be added to the lists.
%
% The addition or removal is done by the \texttt{:NnNNN} auxiliary,
% which performs the catcode assignment (note here that the arguments
% of \cs{char_set_catcode:nn} are each evaluated exactly once), then
% tests whether the new catcode is special or not. If that changed
% compared to the previous catcode, then some work is needed: pass to
% the \texttt{:NNN} auxiliary the single-character control sequence,
% a function acting on token lists, and a function acting on
% sequences. Defining this auxiliary is tricky: the odd
% \texttt{f}-expansion expands the two \cs{tl_if_exist:NT} before the
% definition is performed, and the macro parameter token |#| (we are
% not yet doing a definition) stops the \texttt{f}-expansion.
% In \LaTeXe{}, \cs{@sanitize} differs from \cs{dospecials} in that
% it should not list begin-group and end-group character tokens.
% For this, patch \cs{@@_set_catcode:Nn} by copying its code
% using its \texttt{o}-expansion with arguments |#1| and |#2|
% (braces are needed because each argument is literally two tokens,
% a macro parameter character and a digit), and appending to it some
% code that removes the single-character control sequence from
% \cs{@sanitize} if the (new) catcode is $1$ or $2$.
% \begin{macrocode}
\group_begin:
\tex_catcode:D `@ = \c_eleven
\tex_catcode:D \c_zero = \c_twelve
\cs_new_protected:Npn \char_set_catcode:nn #1#2
{
\group_begin:
\char_set_lccode:nn { 0 } {#1}
\tex_lowercase:D
{ \group_end: \@@_set_catcode:Nn ^^@ } {#2}
}
\tex_catcode:D \c_zero = \c_thirteen
\cs_new_protected:Npn \@@_set_catcode:Nn #1#2
{
\int_compare:nNnTF { \tex_catcode:D `#1 / \c_two } = \c_six
{
\@@_set_catcode:NnNNN #1 {#2} \int_compare:nNnF
\tl_put_right:Nn \seq_put_right:Nn
}
{
\@@_set_catcode:NnNNN #1 {#2} \int_compare:nNnT
\tl_remove_all:Nn \seq_remove_all:Nn
}
\int_compare:nNnT { \tex_catcode:D `#1 } = \c_thirteen
{
\group_begin:
\char_set_lccode:nn { 0 } { `#1 }
\tex_lowercase:D
{
\group_end:
\seq_if_in:NnF \l_char_active_seq { ^^@ }
{ \seq_put_right:Nn \l_char_active_seq { ^^@ } }
}
}
}
\cs_new_protected:Npn \@@_set_catcode:NnNNN #1#2#3#4#5
{
\tex_catcode:D `#1 = \__int_eval:w #2 \__int_eval_end:
#3 { \tex_catcode:D `#1 / \c_two } = \c_six
{
\group_begin: \exp_args:NNc \group_end:
\@@_set_catcode:NNN {#1} #4 #5
}
}
\exp_args:Nnf \use:n
{ \cs_new_protected:Npn \@@_set_catcode:NNN #1#2#3 }
{
%<*package>
\tl_if_exist:NT \dospecials
{
\tl_if_exist:NT \@sanitize { #2 \@sanitize { \@makeother #1 } }
#2 \dospecials { \do #1 }
}
%</package>
#3 \l_char_special_seq {#1}
}
%<*package>
\tl_if_exist:NT \@sanitize
{
\exp_args:Nno \use:n
{ \cs_gset_protected:Npn \@@_set_catcode:Nn #1#2 }
{
\@@_set_catcode:Nn {#1} {#2}
\int_compare:nNnT { \tex_catcode:D `#1 / \c_two } = \c_one
{
\group_begin: \exp_args:NNNx \group_end:
\tl_remove_all:Nn \@sanitize
{ \exp_not:N \@makeother \exp_not:c {#1} }
}
}
}
%</package>
\cs_new:Npn \char_value_catcode:n #1
{ \tex_the:D \tex_catcode:D \__int_eval:w #1\__int_eval_end: }
\cs_new_protected:Npn \char_show_value_catcode:n #1
{ \__msg_show_wrap:n { > ~ \char_value_catcode:n {#1} } }
\group_end:
% \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \begin{macro}
% {
% \char_set_catcode_escape:N ,
% \char_set_catcode_group_begin:N ,
% \char_set_catcode_group_end:N ,
% \char_set_catcode_math_toggle:N ,
% \char_set_catcode_alignment:N ,
% \char_set_catcode_end_line:N ,
% \char_set_catcode_parameter:N ,
% \char_set_catcode_math_superscript:N ,
% \char_set_catcode_math_subscript:N ,
% \char_set_catcode_ignore:N ,
% \char_set_catcode_space:N ,
% \char_set_catcode_letter:N ,
% \char_set_catcode_other:N ,
% \char_set_catcode_active:N ,
% \char_set_catcode_comment:N ,
% \char_set_catcode_invalid:N
% }
% \begin{macrocode}
\cs_new_protected:Npn \char_set_catcode_escape:N #1
{ \char_set_catcode:nn { `#1 } \c_zero }
\cs_new_protected:Npn \char_set_catcode_group_begin:N #1
{ \char_set_catcode:nn { `#1 } \c_one }
\cs_new_protected:Npn \char_set_catcode_group_end:N #1
{ \char_set_catcode:nn { `#1 } \c_two }
\cs_new_protected:Npn \char_set_catcode_math_toggle:N #1
{ \char_set_catcode:nn { `#1 } \c_three }
\cs_new_protected:Npn \char_set_catcode_alignment:N #1
{ \char_set_catcode:nn { `#1 } \c_four }
\cs_new_protected:Npn \char_set_catcode_end_line:N #1
{ \char_set_catcode:nn { `#1 } \c_five }
\cs_new_protected:Npn \char_set_catcode_parameter:N #1
{ \char_set_catcode:nn { `#1 } \c_six }
\cs_new_protected:Npn \char_set_catcode_math_superscript:N #1
{ \char_set_catcode:nn { `#1 } \c_seven }
\cs_new_protected:Npn \char_set_catcode_math_subscript:N #1
{ \char_set_catcode:nn { `#1 } \c_eight }
\cs_new_protected:Npn \char_set_catcode_ignore:N #1
{ \char_set_catcode:nn { `#1 } \c_nine }
\cs_new_protected:Npn \char_set_catcode_space:N #1
{ \char_set_catcode:nn { `#1 } \c_ten }
\cs_new_protected:Npn \char_set_catcode_letter:N #1
{ \char_set_catcode:nn { `#1 } \c_eleven }
\cs_new_protected:Npn \char_set_catcode_other:N #1
{ \char_set_catcode:nn { `#1 } \c_twelve }
\cs_new_protected:Npn \char_set_catcode_active:N #1
{ \char_set_catcode:nn { `#1 } \c_thirteen }
\cs_new_protected:Npn \char_set_catcode_comment:N #1
{ \char_set_catcode:nn { `#1 } \c_fourteen }
\cs_new_protected:Npn \char_set_catcode_invalid:N #1
{ \char_set_catcode:nn { `#1 } \c_fifteen }
% \end{macrocode}
% \end{macro}
%
% \begin{macro}
% {
% \char_set_catcode_escape:n ,
% \char_set_catcode_group_begin:n ,
% \char_set_catcode_group_end:n ,
% \char_set_catcode_math_toggle:n ,
% \char_set_catcode_alignment:n ,
% \char_set_catcode_end_line:n ,
% \char_set_catcode_parameter:n ,
% \char_set_catcode_math_superscript:n ,
% \char_set_catcode_math_subscript:n ,
% \char_set_catcode_ignore:n ,
% \char_set_catcode_space:n ,
% \char_set_catcode_letter:n ,
% \char_set_catcode_other:n ,
% \char_set_catcode_active:n ,
% \char_set_catcode_comment:n ,
% \char_set_catcode_invalid:n
% }
% \begin{macrocode}
\cs_new_protected:Npn \char_set_catcode_escape:n #1
{ \char_set_catcode:nn {#1} \c_zero }
\cs_new_protected:Npn \char_set_catcode_group_begin:n #1
{ \char_set_catcode:nn {#1} \c_one }
\cs_new_protected:Npn \char_set_catcode_group_end:n #1
{ \char_set_catcode:nn {#1} \c_two }
\cs_new_protected:Npn \char_set_catcode_math_toggle:n #1
{ \char_set_catcode:nn {#1} \c_three }
\cs_new_protected:Npn \char_set_catcode_alignment:n #1
{ \char_set_catcode:nn {#1} \c_four }
\cs_new_protected:Npn \char_set_catcode_end_line:n #1
{ \char_set_catcode:nn {#1} \c_five }
\cs_new_protected:Npn \char_set_catcode_parameter:n #1
{ \char_set_catcode:nn {#1} \c_six }
\cs_new_protected:Npn \char_set_catcode_math_superscript:n #1
{ \char_set_catcode:nn {#1} \c_seven }
\cs_new_protected:Npn \char_set_catcode_math_subscript:n #1
{ \char_set_catcode:nn {#1} \c_eight }
\cs_new_protected:Npn \char_set_catcode_ignore:n #1
{ \char_set_catcode:nn {#1} \c_nine }
\cs_new_protected:Npn \char_set_catcode_space:n #1
{ \char_set_catcode:nn {#1} \c_ten }
\cs_new_protected:Npn \char_set_catcode_letter:n #1
{ \char_set_catcode:nn {#1} \c_eleven }
\cs_new_protected:Npn \char_set_catcode_other:n #1
{ \char_set_catcode:nn {#1} \c_twelve }
\cs_new_protected:Npn \char_set_catcode_active:n #1
{ \char_set_catcode:nn {#1} \c_thirteen }
\cs_new_protected:Npn \char_set_catcode_comment:n #1
{ \char_set_catcode:nn {#1} \c_fourteen }
\cs_new_protected:Npn \char_set_catcode_invalid:n #1
{ \char_set_catcode:nn {#1} \c_fifteen }
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\char_set_mathcode:nn}
% \begin{macro}{\char_value_mathcode:n}
% \begin{macro}{\char_show_value_mathcode:n}
% \begin{macro}{\char_set_lccode:nn}
% \begin{macro}{\char_value_lccode:n}
% \begin{macro}{\char_show_value_lccode:n}
% \begin{macro}{\char_set_uccode:nn}
% \begin{macro}{\char_value_uccode:n}
% \begin{macro}{\char_show_value_uccode:n}
% \begin{macro}{\char_set_sfcode:nn}
% \begin{macro}{\char_value_sfcode:n}
% \begin{macro}{\char_show_value_sfcode:n}
% Pretty repetitive, but necessary!
% \begin{macrocode}
\cs_new_protected:Npn \char_set_mathcode:nn #1#2
{
\tex_mathcode:D \__int_eval:w #1 \__int_eval_end:
= \__int_eval:w #2 \__int_eval_end:
}
\cs_new:Npn \char_value_mathcode:n #1
{ \tex_the:D \tex_mathcode:D \__int_eval:w #1\__int_eval_end: }
\cs_new_protected:Npn \char_show_value_mathcode:n #1
{ \__msg_show_wrap:n { > ~ \char_value_mathcode:n {#1} } }
\cs_new_protected:Npn \char_set_lccode:nn #1#2
{
\tex_lccode:D \__int_eval:w #1 \__int_eval_end:
= \__int_eval:w #2 \__int_eval_end:
}
\cs_new:Npn \char_value_lccode:n #1
{ \tex_the:D \tex_lccode:D \__int_eval:w #1\__int_eval_end: }
\cs_new_protected:Npn \char_show_value_lccode:n #1
{ \__msg_show_wrap:n { > ~ \char_value_lccode:n {#1} } }
\cs_new_protected:Npn \char_set_uccode:nn #1#2
{
\tex_uccode:D \__int_eval:w #1 \__int_eval_end:
= \__int_eval:w #2 \__int_eval_end:
}
\cs_new:Npn \char_value_uccode:n #1
{ \tex_the:D \tex_uccode:D \__int_eval:w #1\__int_eval_end: }
\cs_new_protected:Npn \char_show_value_uccode:n #1
{ \__msg_show_wrap:n { > ~ \char_value_uccode:n {#1} } }
\cs_new_protected:Npn \char_set_sfcode:nn #1#2
{
\tex_sfcode:D \__int_eval:w #1 \__int_eval_end:
= \__int_eval:w #2 \__int_eval_end:
}
\cs_new:Npn \char_value_sfcode:n #1
{ \tex_the:D \tex_sfcode:D \__int_eval:w #1\__int_eval_end: }
\cs_new_protected:Npn \char_show_value_sfcode:n #1
{ \__msg_show_wrap:n { > ~ \char_value_sfcode:n {#1} } }
% \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \begin{variable}{\l_char_active_seq, \l_char_special_seq}
% Two sequences for dealing with special characters. They must be defined
% before \cs{char_set_catcode:nn} can be used. The first is characters
% which may be active, and contains the active characters themselves to
% allow easy redefinition. The second longer list is for \enquote{special}
% characters more generally, and these are escaped so that for example
% bulk code assignments can be carried out. In both cases, the order is
% by \textsc{ascii} character code (as is done in for example
% \cs{ExplSyntaxOn}). The only complication is dealing with |_|, which
% requires the use of \cs{use:n} \emph{and} \cs{use:nn}.
% \begin{macrocode}
\seq_new:N \l_char_special_seq
\seq_set_split:Nnn \l_char_special_seq { }
{ \ \" \# \$ \% \& \\ \^ \_ \{ \} \~ }
\seq_new:N \l_char_active_seq
\use:n
{
\group_begin:
\char_set_catcode_active:N \"
\char_set_catcode_active:N \$
\char_set_catcode_active:N \&
\char_set_catcode_active:N \^
\char_set_catcode_active:N \_
\char_set_catcode_active:N \~
\use:nn
{
\group_end:
\seq_set_split:Nnn \l_char_active_seq { }
}
}
{ { " $ & ^ _ ~ } } %$
% \end{macrocode}
% \end{variable}
%
% \subsection{Generic tokens}
%
% \begin{macrocode}
%<@@=token>
% \end{macrocode}
%
% \begin{macro}{\token_to_meaning:N, \token_to_meaning:c}
% \begin{macro}{\token_to_str:N, \token_to_str:c}
% These are all defined in \pkg{l3basics}, as they are needed
% \enquote{early}. This is just a reminder!
% \end{macro}
% \end{macro}
%
% \begin{macro}{\token_new:Nn}
% Creates a new token.
% \begin{macrocode}
\cs_new_protected:Npn \token_new:Nn #1#2 { \cs_new_eq:NN #1 #2 }
% \end{macrocode}
% \end{macro}
%
% \begin{macro}
% {
% \c_group_begin_token,
% \c_group_end_token,
% \c_math_toggle_token,
% \c_alignment_token,
% \c_parameter_token,
% \c_math_superscript_token,
% \c_math_subscript_token,
% \c_space_token,
% \c_catcode_letter_token,
% \c_catcode_other_token
% }
% We define these useful tokens. For the brace and space tokens things have
% to be done by hand: the formal argument spec.~for \cs{cs_new_eq:NN} does
% not cover them so we do things by hand. (As currently coded it would
% \emph{work} with \cs{cs_new_eq:NN} but that's not really a great idea to
% show off: we want people to stick to the defined interfaces and that
% includes us.) So that these few odd names go into the log when appropriate
% there is a need to hand-apply the \cs{__chk_if_free_cs:N} check.
% \begin{macrocode}
\group_begin:
\__chk_if_free_cs:N \c_group_begin_token
\tex_global:D \tex_let:D \c_group_begin_token {
\__chk_if_free_cs:N \c_group_end_token
\tex_global:D \tex_let:D \c_group_end_token }
\char_set_catcode_math_toggle:N \*
\cs_new_eq:NN \c_math_toggle_token *
\char_set_catcode_alignment:N \*
\cs_new_eq:NN \c_alignment_token *
\cs_new_eq:NN \c_parameter_token #
\cs_new_eq:NN \c_math_superscript_token ^
\char_set_catcode_math_subscript:N \*
\cs_new_eq:NN \c_math_subscript_token *
\__chk_if_free_cs:N \c_space_token
\use:n { \tex_global:D \tex_let:D \c_space_token = ~ } ~
\cs_new_eq:NN \c_catcode_letter_token a
\cs_new_eq:NN \c_catcode_other_token 1
\group_end:
% \end{macrocode}
% \end{macro}
%
% \begin{variable}{\c_catcode_active_tl}
% Not an implicit token!
% \begin{macrocode}
\group_begin:
\char_set_catcode_active:N \*
\tl_const:Nn \c_catcode_active_tl { \exp_not:N * }
\group_end:
% \end{macrocode}
% \end{variable}
%
% \subsection{Token conditionals}
%
% \begin{macro}[pTF]{\token_if_group_begin:N}
% Check if token is a begin group token. We use the constant
% \cs{c_group_begin_token} for this.
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_group_begin:N #1 { p , T , F , TF }
{
\if_catcode:w \exp_not:N #1 \c_group_begin_token
\prg_return_true: \else: \prg_return_false: \fi:
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}[pTF]{\token_if_group_end:N}
% Check if token is a end group token. We use the constant
% \cs{c_group_end_token} for this.
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_group_end:N #1 { p , T , F , TF }
{
\if_catcode:w \exp_not:N #1 \c_group_end_token
\prg_return_true: \else: \prg_return_false: \fi:
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}[pTF]{\token_if_math_toggle:N}
% Check if token is a math shift token. We use the constant
% \cs{c_math_toggle_token} for this.
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_math_toggle:N #1 { p , T , F , TF }
{
\if_catcode:w \exp_not:N #1 \c_math_toggle_token
\prg_return_true: \else: \prg_return_false: \fi:
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}[pTF]{\token_if_alignment:N}
% Check if token is an alignment tab token. We use the constant
% \cs{c_alignment_token} for this.
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_alignment:N #1 { p , T , F , TF }
{
\if_catcode:w \exp_not:N #1 \c_alignment_token
\prg_return_true: \else: \prg_return_false: \fi:
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}[pTF]{\token_if_parameter:N}
% Check if token is a parameter token. We use the constant
% \cs{c_parameter_token} for this. We have to trick \TeX{} a bit to
% avoid an error message: within a group we prevent
% \cs{c_parameter_token} from behaving like a macro parameter character.
% The definitions of \cs{prg_new_conditional:Npnn} are global, so they
% will remain after the group.
% \begin{macrocode}
\group_begin:
\cs_set_eq:NN \c_parameter_token \scan_stop:
\prg_new_conditional:Npnn \token_if_parameter:N #1 { p , T , F , TF }
{
\if_catcode:w \exp_not:N #1 \c_parameter_token
\prg_return_true: \else: \prg_return_false: \fi:
}
\group_end:
% \end{macrocode}
% \end{macro}
%
% \begin{macro}[pTF]{\token_if_math_superscript:N}
% Check if token is a math superscript token. We use the constant
% \cs{c_math_superscript_token} for this.
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_math_superscript:N #1
{ p , T , F , TF }
{
\if_catcode:w \exp_not:N #1 \c_math_superscript_token
\prg_return_true: \else: \prg_return_false: \fi:
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}[pTF]{\token_if_math_subscript:N}
% Check if token is a math subscript token. We use the constant
% \cs{c_math_subscript_token} for this.
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_math_subscript:N #1 { p , T , F , TF }
{
\if_catcode:w \exp_not:N #1 \c_math_subscript_token
\prg_return_true: \else: \prg_return_false: \fi:
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}[pTF]{\token_if_space:N}
% Check if token is a space token. We use the constant
% \cs{c_space_token} for this.
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_space:N #1 { p , T , F , TF }
{
\if_catcode:w \exp_not:N #1 \c_space_token
\prg_return_true: \else: \prg_return_false: \fi:
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}[pTF]{\token_if_letter:N}
% Check if token is a letter token. We use the constant
% \cs{c_catcode_letter_token} for this.
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_letter:N #1 { p , T , F , TF }
{
\if_catcode:w \exp_not:N #1 \c_catcode_letter_token
\prg_return_true: \else: \prg_return_false: \fi:
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}[pTF]{\token_if_other:N}
% Check if token is an other char token. We use the constant
% \cs{c_catcode_other_token} for this.
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_other:N #1 { p , T , F , TF }
{
\if_catcode:w \exp_not:N #1 \c_catcode_other_token
\prg_return_true: \else: \prg_return_false: \fi:
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}[pTF]{\token_if_active:N}
% Check if token is an active char token. We use the constant
% \cs{c_catcode_active_tl} for this. A technical point is that
% \cs{c_catcode_active_tl} is in fact a macro expanding to
% |\exp_not:N *|, where |*| is active.
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_active:N #1 { p , T , F , TF }
{
\if_catcode:w \exp_not:N #1 \c_catcode_active_tl
\prg_return_true: \else: \prg_return_false: \fi:
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}[pTF]{\token_if_eq_meaning:NN}
% Check if the tokens |#1| and |#2| have same meaning.
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_eq_meaning:NN #1#2 { p , T , F , TF }
{
\if_meaning:w #1 #2
\prg_return_true: \else: \prg_return_false: \fi:
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}[pTF]{\token_if_eq_catcode:NN}
% Check if the tokens |#1| and |#2| have same category code.
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_eq_catcode:NN #1#2 { p , T , F , TF }
{
\if_catcode:w \exp_not:N #1 \exp_not:N #2
\prg_return_true: \else: \prg_return_false: \fi:
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}[pTF]{\token_if_eq_charcode:NN}
% Check if the tokens |#1| and |#2| have same character code.
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_eq_charcode:NN #1#2 { p , T , F , TF }
{
\if_charcode:w \exp_not:N #1 \exp_not:N #2
\prg_return_true: \else: \prg_return_false: \fi:
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}[pTF]{\token_if_macro:N}
% \begin{macro}[aux]{\@@_if_macro_p:w}
% When a token is a macro, \cs{token_to_meaning:N} will always output
% something like |\long macro:#1->#1| so we could naively check to
% see if the meaning contains |->|. However, this can fail the five
% \tn{...mark} primitives, whose meaning has the form
% |...mark:|\meta{user material}. The problem is that the
% \meta{user material} can contain |->|.
%
% However, only characters, macros, and marks can contain the colon
% character. The idea is thus to grab until the first |:|, and analyse
% what is left. However, macros can have any combination of |\long|,
% |\protected| or |\outer| (not used in \LaTeX3) before the string
% |macro:|. We thus only select the part of the meaning between
% the first |ma| and the first following |:|. If this string is
% |cro|, then we have a macro. If the string is |rk|, then we have
% a mark. The string can also be |cro parameter character | for a
% colon with a weird category code (namely the usual category code
% of |#|). Otherwise, it is empty.
%
% This relies on the fact that |\long|, |\protected|, |\outer|
% cannot contain |ma|, regardless of the escape character, even if
% the escape character is |m|\ldots{}
%
% Both |ma| and |:| must be of category code $12$ (other), so are
% detokenized.
%
% \begin{macrocode}
\use:x
{
\prg_new_conditional:Npnn \exp_not:N \token_if_macro:N ##1
{ p , T , F , TF }
{
\exp_not:N \exp_after:wN \exp_not:N \@@_if_macro_p:w
\exp_not:N \token_to_meaning:N ##1 \tl_to_str:n { ma : }
\exp_not:N \q_stop
}
\cs_new:Npn \exp_not:N \@@_if_macro_p:w
##1 \tl_to_str:n { ma } ##2 \c_colon_str ##3 \exp_not:N \q_stop
}
{
\if_int_compare:w \__str_if_eq_x:nn { #2 } { cro } = \c_zero
\prg_return_true:
\else:
\prg_return_false:
\fi:
}
% \end{macrocode}
% \end{macro}
% \end{macro}
%
% \begin{macro}[pTF]{\token_if_cs:N}
% Check if token has same catcode as a control sequence. This
% follows the same pattern as for \cs{token_if_letter:N} \emph{etc.}
% We use \cs{scan_stop:} for this.
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_cs:N #1 { p , T , F , TF }
{
\if_catcode:w \exp_not:N #1 \scan_stop:
\prg_return_true: \else: \prg_return_false: \fi:
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}[pTF]{\token_if_expandable:N}
% Check if token is expandable. We use the fact that \TeX{} will
% temporarily convert \cs{exp_not:N} \meta{token} into \cs{scan_stop:}
% if \meta{token} is expandable. An \texttt{undefined} token is not
% considered as expandable. No problem nesting the conditionals,
% since the third |#1| is only skipped if it is non-expandable (hence
% not part of \TeX{}'s conditional apparatus).
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_expandable:N #1 { p , T , F , TF }
{
\exp_after:wN \if_meaning:w \exp_not:N #1 #1
\prg_return_false:
\else:
\if_cs_exist:N #1
\prg_return_true:
\else:
\prg_return_false:
\fi:
\fi:
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}[pTF]
% {
% \token_if_chardef:N, \token_if_mathchardef:N,
% \token_if_dim_register:N, \token_if_int_register:N,
% \token_if_muskip_register:N,
% \token_if_skip_register:N, \token_if_toks_register:N,
% \token_if_long_macro:N,
% \token_if_protected_macro:N, \token_if_protected_long_macro:N,
% }
% \begin{macro}[aux]
% {
% \@@_if_chardef:w,
% \@@_if_dim_register:w,
% \@@_if_int_register:w,
% \@@_if_muskip_register:w,
% \@@_if_skip_register:w,
% \@@_if_toks_register:w,
% \@@_if_protected_macro:w,
% \@@_if_long_macro:w,
% }
% Most of these functions have to check the meaning of the token in
% question so we need to do some checkups on which characters are
% output by \cs{token_to_meaning:N}. As usual, these characters have
% catcode 12 so we must do some serious substitutions in the code
% below\dots
% \begin{macrocode}
\group_begin:
\char_set_lccode:nn { `T } { `T }
\char_set_lccode:nn { `F } { `F }
\char_set_lccode:nn { `X } { `n }
\char_set_lccode:nn { `Y } { `t }
\char_set_lccode:nn { `Z } { `d }
\tl_map_inline:nn { A C E G H I K L M O P R S U X Y Z R " }
{ \char_set_catcode:nn { `#1 } \c_twelve }
% \end{macrocode}
% We convert the token list to lower case and restore the catcode and
% lowercase code changes.
% \begin{macrocode}
\tex_lowercase:D
{
\group_end:
% \end{macrocode}
% First up is checking if something has been defined with
% \tn{chardef} or \tn{mathchardef}. This is easy since \TeX{}
% thinks of such tokens as hexadecimal so it stores them as
% |\char"|\meta{hex~number} or |\mathchar"|\meta{hex~number}.
% Grab until the first occurrence of |char"|, and compare what
% precedes with |\| or |\math|. In fact, the escape character
% may not be a backslash, so we compare with the result of
% converting some other control sequence to a string, namely
% |\char| or |\mathchar| (the auxiliary adds the |char| back).
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_chardef:N #1 { p , T , F , TF }
{
\__str_if_eq_x_return:nn
{
\exp_after:wN \@@_if_chardef:w
\token_to_meaning:N #1 CHAR" \q_stop
}
{ \token_to_str:N \char }
}
\prg_new_conditional:Npnn \token_if_mathchardef:N #1 { p , T , F , TF }
{
\__str_if_eq_x_return:nn
{
\exp_after:wN \@@_if_chardef:w
\token_to_meaning:N #1 CHAR" \q_stop
}
{ \token_to_str:N \mathchar }
}
\cs_new:Npn \@@_if_chardef:w #1 CHAR" #2 \q_stop { #1 CHAR }
% \end{macrocode}
% Dim registers are a bit more difficult since their \tn{meaning}
% has the form \tn{dimen}\meta{number}, and we must take care of the
% two primitives \tn{dimen} and \tn{dimendef}.
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_dim_register:N #1 { p , T , F , TF }
{
\if_meaning:w \tex_dimen:D #1
\prg_return_false:
\else:
\if_meaning:w \tex_dimendef:D #1
\prg_return_false:
\else:
\__str_if_eq_x_return:nn
{
\exp_after:wN \@@_if_dim_register:w
\token_to_meaning:N #1 ZIMEX \q_stop
}
{ \token_to_str:N \ }
\fi:
\fi:
}
\cs_new:Npn \@@_if_dim_register:w #1 ZIMEX #2 \q_stop { #1 ~ }
% \end{macrocode}
% Integer registers are one step harder since constants are implemented
% differently from variables, and we also have to take care of the
% primitives \tn{count} and \tn{countdef}.
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_int_register:N #1 { p , T , F , TF }
{
% \token_if_chardef:NTF #1 { \prg_return_true: }
% {
% \token_if_mathchardef:NTF #1 { \prg_return_true: }
% {
\if_meaning:w \tex_count:D #1
\prg_return_false:
\else:
\if_meaning:w \tex_countdef:D #1
\prg_return_false:
\else:
\__str_if_eq_x_return:nn
{
\exp_after:wN \@@_if_int_register:w
\token_to_meaning:N #1 COUXY \q_stop
}
{ \token_to_str:N \ }
\fi:
\fi:
% }
% }
}
\cs_new:Npn \@@_if_int_register:w #1 COUXY #2 \q_stop { #1 ~ }
% \end{macrocode}
% Muskip registers are done the same way as the dimension registers.
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_muskip_register:N #1
{ p , T , F , TF }
{
\if_meaning:w \tex_muskip:D #1
\prg_return_false:
\else:
\if_meaning:w \tex_muskipdef:D #1
\prg_return_false:
\else:
\__str_if_eq_x_return:nn
{
\exp_after:wN \@@_if_muskip_register:w
\token_to_meaning:N #1 MUSKIP \q_stop
}
{ \token_to_str:N \ }
\fi:
\fi:
}
\cs_new:Npn \@@_if_muskip_register:w #1 MUSKIP #2 \q_stop { #1 ~ }
% \end{macrocode}
% Skip registers.
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_skip_register:N #1
{ p , T , F , TF }
{
\if_meaning:w \tex_skip:D #1
\prg_return_false:
\else:
\if_meaning:w \tex_skipdef:D #1
\prg_return_false:
\else:
\__str_if_eq_x_return:nn
{
\exp_after:wN \@@_if_skip_register:w
\token_to_meaning:N #1 SKIP \q_stop
}
{ \token_to_str:N \ }
\fi:
\fi:
}
\cs_new:Npn \@@_if_skip_register:w #1 SKIP #2 \q_stop { #1 ~ }
% \end{macrocode}
% Toks registers.
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_toks_register:N #1
{ p , T , F , TF }
{
\if_meaning:w \tex_toks:D #1
\prg_return_false:
\else:
\if_meaning:w \tex_toksdef:D #1
\prg_return_false:
\else:
\__str_if_eq_x_return:nn
{
\exp_after:wN \@@_if_toks_register:w
\token_to_meaning:N #1 YOKS \q_stop
}
{ \token_to_str:N \ }
\fi:
\fi:
}
\cs_new:Npn \@@_if_toks_register:w #1 YOKS #2 \q_stop { #1 ~ }
% \end{macrocode}
% Protected macros.
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_protected_macro:N #1
{ p , T , F , TF }
{
\__str_if_eq_x_return:nn
{
\exp_after:wN \@@_if_protected_macro:w
\token_to_meaning:N #1 PROYECYEZ~MACRO \q_stop
}
{ \token_to_str:N \ }
}
\cs_new:Npn \@@_if_protected_macro:w
#1 PROYECYEZ~MACRO #2 \q_stop { #1 ~ }
% \end{macrocode}
% Long macros and protected long macros share an auxiliary.
% \begin{macrocode}
\prg_new_conditional:Npnn \token_if_long_macro:N #1 { p , T , F , TF }
{
\__str_if_eq_x_return:nn
{
\exp_after:wN \@@_if_long_macro:w
\token_to_meaning:N #1 LOXG~MACRO \q_stop
}
{ \token_to_str:N \ }
}
\prg_new_conditional:Npnn \token_if_protected_long_macro:N #1
{ p , T , F , TF }
{
\__str_if_eq_x_return:nn
{
\exp_after:wN \@@_if_long_macro:w
\token_to_meaning:N #1 LOXG~MACRO \q_stop
}
{ \token_to_str:N \protected \token_to_str:N \ }
}
\cs_new:Npn \@@_if_long_macro:w #1 LOXG~MACRO #2 \q_stop { #1 ~ }
% \end{macrocode}
% Finally the \cs{tex_lowercase:D} ends!
% \begin{macrocode}
}
% \end{macrocode}
% \end{macro}
% \end{macro}
%
% \begin{macro}[pTF]{\token_if_primitive:N}
% \begin{macro}[aux]{\@@_if_primitive:NNw,
% \@@_if_primitive_space:w,
% \@@_if_primitive_nullfont:N,
% \@@_if_primitive_loop:N,
% \@@_if_primitive:Nw,
% \@@_if_primitive_undefined:N}
%^^A See http://groups.google.com/group/comp.text.tex/browse_thread/thread/0a72666873f8753d#
%
% We filter out macros first, because they cause endless trouble later
% otherwise.
%
% Primitives are almost distinguished by the fact that the result
% of \cs{token_to_meaning:N} is formed from letters only. Every other
% token has either a space (e.g., |the letter A|), a digit
% (e.g., |\count123|) or a double quote (e.g., |\char"A|).
%
% Ten exceptions: on the one hand, \cs{tex_undefined:D} is not a
% primitive, but its meaning is |undefined|, only letters;
% on the other hand, \tn{space}, \tn{italiccorr},
% \tn{hyphen}, \tn{firstmark}, \tn{topmark},
% \tn{botmark}, \tn{splitfirstmark}, \tn{splitbotmark},
% and \tn{nullfont} are primitives, but have non-letters
% in their meaning.
%
% We start by removing the two first (non-space) characters from
% the meaning. This removes the escape character (which may be
% inexistent depending on \tn{endlinechar}), and takes care
% of three of the exceptions: \tn{space}, \tn{italiccorr}
% and \tn{hyphen}, whose meaning is at most two characters.
% This leaves a string terminated by some |:|, and \cs{q_stop}.
%
% The meaning of each one of the five \tn{...mark} primitives
% has the form \meta{letters}|:|\meta{user material}. In other words,
% the first non-letter is a colon. We remove everything after the first
% colon.
%
% We are now left with a string, which we must analyze. For primitives,
% it contains only letters. For non-primitives, it contains either
% |"|, or a space, or a digit. Two exceptions remain: \cs{tex_undefined:D},
% which is not a primitive, and \tn{nullfont}, which is a primitive.
%
% Spaces cannot be grabbed in an undelimited way, so we check them
% separately. If there is a space, we test for \tn{nullfont}.
% Otherwise, we go through characters one by one, and stop at the
% first character less than |`A| (this is not quite a test for
% \enquote{only letters}, but is close enough to work in this context).
% If this first character is |:| then we have a primitive, or
% \cs{tex_undefined:D}, and if it is |"| or a digit, then the token
% is not a primitive.
%
% \begin{macrocode}
\tex_chardef:D \c_@@_A_int = `A ~ %
\use:x
{
\prg_new_conditional:Npnn \exp_not:N \token_if_primitive:N ##1
{ p , T , F , TF }
{
\exp_not:N \token_if_macro:NTF ##1
\exp_not:N \prg_return_false:
{
\exp_not:N \exp_after:wN \exp_not:N \@@_if_primitive:NNw
\exp_not:N \token_to_meaning:N ##1
\tl_to_str:n { : : : } \exp_not:N \q_stop ##1
}
}
\cs_new:Npn \exp_not:N \@@_if_primitive:NNw
##1##2 ##3 \c_colon_str ##4 \exp_not:N \q_stop
{
\exp_not:N \tl_if_empty:oTF
{ \exp_not:N \@@_if_primitive_space:w ##3 ~ }
{
\exp_not:N \@@_if_primitive_loop:N ##3
\c_colon_str \exp_not:N \q_stop
}
{ \exp_not:N \@@_if_primitive_nullfont:N }
}
}
\cs_new:Npn \@@_if_primitive_space:w #1 ~ { }
\cs_new:Npn \@@_if_primitive_nullfont:N #1
{
\if_meaning:w \tex_nullfont:D #1
\prg_return_true:
\else:
\prg_return_false:
\fi:
}
\cs_new:Npn \@@_if_primitive_loop:N #1
{
\if_int_compare:w `#1 < \c_@@_A_int %
\exp_after:wN \@@_if_primitive:Nw
\exp_after:wN #1
\else:
\exp_after:wN \@@_if_primitive_loop:N
\fi:
}
\cs_new:Npn \@@_if_primitive:Nw #1 #2 \q_stop
{
\if:w : #1
\exp_after:wN \@@_if_primitive_undefined:N
\else:
\prg_return_false:
\exp_after:wN \use_none:n
\fi:
}
\cs_new:Npn \@@_if_primitive_undefined:N #1
{
\if_cs_exist:N #1
\prg_return_true:
\else:
\prg_return_false:
\fi:
}
% \end{macrocode}
% \end{macro}
% \end{macro}
%
% \subsection{Peeking ahead at the next token}
%
% \begin{macrocode}
%<@@=peek>
% \end{macrocode}
%
% Peeking ahead is implemented using a two part mechanism. The
% outer level provides a defined interface to the lower level material.
% This allows a large amount of code to be shared. There are four
% cases:
% \begin{enumerate}
% \item peek at the next token;
% \item peek at the next non-space token;
% \item peek at the next token and remove it;
% \item peek at the next non-space token and remove it.
% \end{enumerate}
%
% \begin{variable}{\l_peek_token}
% \begin{variable}{\g_peek_token}
% Storage tokens which are publicly documented: the token peeked.
% \begin{macrocode}
\cs_new_eq:NN \l_peek_token ?
\cs_new_eq:NN \g_peek_token ?
% \end{macrocode}
% \end{variable}
% \end{variable}
%
% \begin{variable}{\l_@@_search_token}
% The token to search for as an implicit token:
% \emph{cf.}~\cs{l_@@_search_tl}.
% \begin{macrocode}
\cs_new_eq:NN \l_@@_search_token ?
% \end{macrocode}
% \end{variable}
%
% \begin{variable}{\l_@@_search_tl}
% The token to search for as an explicit token:
% \emph{cf.}~\cs{l_@@_search_token}.
% \begin{macrocode}
\tl_new:N \l_@@_search_tl
% \end{macrocode}
% \end{variable}
%
% \begin{macro}[aux]
% {\@@_true:w, \@@_true_aux:w, \@@_false:w, \@@_tmp:w}
% Functions used by the branching and space-stripping code.
% \begin{macrocode}
\cs_new_nopar:Npn \@@_true:w { }
\cs_new_nopar:Npn \@@_true_aux:w { }
\cs_new_nopar:Npn \@@_false:w { }
\cs_new:Npn \@@_tmp:w { }
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\peek_after:Nw}
% \begin{macro}{\peek_gafter:Nw}
% Simple wrappers for \tn{futurelet}: no arguments absorbed
% here.
% \begin{macrocode}
\cs_new_protected_nopar:Npn \peek_after:Nw
{ \tex_futurelet:D \l_peek_token }
\cs_new_protected_nopar:Npn \peek_gafter:Nw
{ \tex_global:D \tex_futurelet:D \g_peek_token }
% \end{macrocode}
% \end{macro}
% \end{macro}
%
% \begin{macro}[aux]{\@@_true_remove:w}
% A function to remove the next token and then regain control.
% \begin{macrocode}
\cs_new_protected:Npn \@@_true_remove:w
{
\group_align_safe_end:
\tex_afterassignment:D \@@_true_aux:w
\cs_set_eq:NN \@@_tmp:w
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}[TF]{\@@_token_generic:NN}
% The generic function stores the test token in both implicit and
% explicit modes, and the \texttt{true} and \texttt{false} code as
% token lists, more or less. The two branches have to be absorbed here
% as the input stream needs to be cleared for the peek function itself.
% \begin{macrocode}
\cs_new_protected:Npn \@@_token_generic:NNTF #1#2#3#4
{
\cs_set_eq:NN \l_@@_search_token #2
\tl_set:Nn \l_@@_search_tl {#2}
\cs_set_nopar:Npx \@@_true:w
{
\exp_not:N \group_align_safe_end:
\exp_not:n {#3}
}
\cs_set_nopar:Npx \@@_false:w
{
\exp_not:N \group_align_safe_end:
\exp_not:n {#4}
}
\group_align_safe_begin:
\peek_after:Nw #1
}
\cs_new_protected:Npn \@@_token_generic:NNT #1#2#3
{ \@@_token_generic:NNTF #1 #2 {#3} { } }
\cs_new_protected:Npn \@@_token_generic:NNF #1#2#3
{ \@@_token_generic:NNTF #1 #2 { } {#3} }
% \end{macrocode}
% \end{macro}
%
% \begin{macro}[TF]{\@@_token_remove_generic:NN}
% For token removal there needs to be a call to the auxiliary
% function which does the work.
% \begin{macrocode}
\cs_new_protected:Npn \@@_token_remove_generic:NNTF #1#2#3#4
{
\cs_set_eq:NN \l_@@_search_token #2
\tl_set:Nn \l_@@_search_tl {#2}
\cs_set_eq:NN \@@_true:w \@@_true_remove:w
\cs_set_nopar:Npx \@@_true_aux:w { \exp_not:n {#3} }
\cs_set_nopar:Npx \@@_false:w
{
\exp_not:N \group_align_safe_end:
\exp_not:n {#4}
}
\group_align_safe_begin:
\peek_after:Nw #1
}
\cs_new_protected:Npn \@@_token_remove_generic:NNT #1#2#3
{ \@@_token_remove_generic:NNTF #1 #2 {#3} { } }
\cs_new_protected:Npn \@@_token_remove_generic:NNF #1#2#3
{ \@@_token_remove_generic:NNTF #1 #2 { } {#3} }
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\@@_execute_branches_meaning:}
% The meaning test is straight forward.
% \begin{macrocode}
\cs_new_nopar:Npn \@@_execute_branches_meaning:
{
\if_meaning:w \l_peek_token \l_@@_search_token
\exp_after:wN \@@_true:w
\else:
\exp_after:wN \@@_false:w
\fi:
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\@@_execute_branches_catcode:, \@@_execute_branches_charcode:}
% \begin{macro}[aux]
% {
% \@@_execute_branches_catcode_aux: ,
% \@@_execute_branches_catcode_auxii:N ,
% \@@_execute_branches_catcode_auxiii:
% }
% The catcode and charcode tests are very similar, and in order to use
% the same auxiliaries we do something a little bit odd, firing
% \cs{if_catcode:w} and \cs{if_charcode:w} before finding the operands
% for those tests, which will only be given in the |auxii:N| and
% |auxiii:| auxiliaries. For our purposes, three kinds of tokens may
% follow the peeking function:
% \begin{itemize}
% \item control sequences which are not equal to a non-active
% character token (\emph{e.g.}, macro, primitive);
% \item active characters which are not equal to a non-active
% character token (\emph{e.g.}, macro, primitive);
% \item explicit non-active character tokens, or control sequences
% or active characters set equal to a non-active character token.
% \end{itemize}
% The first two cases are not distinguishable simply using \TeX{}'s
% \tn{futurelet}, because we can only access the \tn{meaning} of
% tokens in that way. In those cases, detected thanks to a
% comparison with \cs{scan_stop:}, we grab the following token, and
% compare it explicitly with the explicit search token stored in
% \cs{l_@@_search_tl}. The \cs{exp_not:N} prevents outer macros
% (coming from non-\LaTeX3 code) from blowing up. In the third case,
% \cs{l_peek_token} is good enough for the test, and we compare it
% again with the explicit search token. Just like the peek token, the
% search token may be of any of the three types above, hence the need
% to use the explicit token that was given to the peek function.
% \begin{macrocode}
\cs_new_nopar:Npn \@@_execute_branches_catcode:
{ \if_catcode:w \@@_execute_branches_catcode_aux: }
\cs_new_nopar:Npn \@@_execute_branches_charcode:
{ \if_charcode:w \@@_execute_branches_catcode_aux: }
\cs_new_nopar:Npn \@@_execute_branches_catcode_aux:
{
\if_catcode:w \exp_not:N \l_peek_token \scan_stop:
\exp_after:wN \exp_after:wN
\exp_after:wN \@@_execute_branches_catcode_auxii:N
\exp_after:wN \exp_not:N
\else:
\exp_after:wN \@@_execute_branches_catcode_auxiii:
\fi:
}
\cs_new:Npn \@@_execute_branches_catcode_auxii:N #1
{
\exp_not:N #1
\exp_after:wN \exp_not:N \l_@@_search_tl
\exp_after:wN \@@_true:w
\else:
\exp_after:wN \@@_false:w
\fi:
#1
}
\cs_new_nopar:Npn \@@_execute_branches_catcode_auxiii:
{
\exp_not:N \l_peek_token
\exp_after:wN \exp_not:N \l_@@_search_tl
\exp_after:wN \@@_true:w
\else:
\exp_after:wN \@@_false:w
\fi:
}
% \end{macrocode}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\@@_ignore_spaces_execute_branches:}
% This function removes one space token at a time, and calls
% \cs{@@_execute_branches:} when encountering the first non-space
% token. We directly use the primitive meaning test rather than
% \cs{token_if_eq_meaning:NNTF} because \cs{l_peek_token} may be an
% outer macro (coming from non-\LaTeX3 packages). Spaces are removed
% using a side-effect of \texttt{f}-expansion:
% |\exp:w \exp_end_continue_f:w| removes one space.
% \begin{macrocode}
\cs_new_protected_nopar:Npn \@@_ignore_spaces_execute_branches:
{
\if_meaning:w \l_peek_token \c_space_token
\exp_after:wN \peek_after:Nw
\exp_after:wN \@@_ignore_spaces_execute_branches:
\exp:w \exp_end_continue_f:w
\else:
\exp_after:wN \@@_execute_branches:
\fi:
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}[aux]{\@@_def:nnnn}
% \begin{macro}[aux]{\@@_def:nnnnn}
% The public functions themselves cannot be defined using
% \cs{prg_new_conditional:Npnn} and so a couple of auxiliary functions
% are used. As a result, everything is done inside a group. As a result
% things are a bit complicated.
% \begin{macrocode}
\group_begin:
\cs_set:Npn \@@_def:nnnn #1#2#3#4
{
\@@_def:nnnnn {#1} {#2} {#3} {#4} { TF }
\@@_def:nnnnn {#1} {#2} {#3} {#4} { T }
\@@_def:nnnnn {#1} {#2} {#3} {#4} { F }
}
\cs_set:Npn \@@_def:nnnnn #1#2#3#4#5
{
\cs_new_protected_nopar:cpx { #1 #5 }
{
\tl_if_empty:nF {#2}
{ \exp_not:n { \cs_set_eq:NN \@@_execute_branches: #2 } }
\exp_not:c { #3 #5 }
\exp_not:n {#4}
}
}
% \end{macrocode}
% \end{macro}
% \end{macro}
% \begin{macro}[TF]
% {
% \peek_catcode:N, \peek_catcode_ignore_spaces:N,
% \peek_catcode_remove:N, \peek_catcode_remove_ignore_spaces:N
% }
% With everything in place the definitions can take place. First for
% category codes.
% \begin{macrocode}
\@@_def:nnnn { peek_catcode:N }
{ }
{ @@_token_generic:NN }
{ \@@_execute_branches_catcode: }
\@@_def:nnnn { peek_catcode_ignore_spaces:N }
{ \@@_execute_branches_catcode: }
{ @@_token_generic:NN }
{ \@@_ignore_spaces_execute_branches: }
\@@_def:nnnn { peek_catcode_remove:N }
{ }
{ @@_token_remove_generic:NN }
{ \@@_execute_branches_catcode: }
\@@_def:nnnn { peek_catcode_remove_ignore_spaces:N }
{ \@@_execute_branches_catcode: }
{ @@_token_remove_generic:NN }
{ \@@_ignore_spaces_execute_branches: }
% \end{macrocode}
% \end{macro}
% \begin{macro}[TF]
% {
% \peek_charcode:N, \peek_charcode_ignore_spaces:N,
% \peek_charcode_remove:N, \peek_charcode_remove_ignore_spaces:N
% }
% Then for character codes.
% \begin{macrocode}
\@@_def:nnnn { peek_charcode:N }
{ }
{ @@_token_generic:NN }
{ \@@_execute_branches_charcode: }
\@@_def:nnnn { peek_charcode_ignore_spaces:N }
{ \@@_execute_branches_charcode: }
{ @@_token_generic:NN }
{ \@@_ignore_spaces_execute_branches: }
\@@_def:nnnn { peek_charcode_remove:N }
{ }
{ @@_token_remove_generic:NN }
{ \@@_execute_branches_charcode: }
\@@_def:nnnn { peek_charcode_remove_ignore_spaces:N }
{ \@@_execute_branches_charcode: }
{ @@_token_remove_generic:NN }
{ \@@_ignore_spaces_execute_branches: }
% \end{macrocode}
% \end{macro}
% \begin{macro}[TF]
% {
% \peek_meaning:N, \peek_meaning_ignore_spaces:N,
% \peek_meaning_remove:N, \peek_meaning_remove_ignore_spaces:N
% }
% Finally for meaning, with the group closed to remove the temporary
% definition functions.
% \begin{macrocode}
\@@_def:nnnn { peek_meaning:N }
{ }
{ @@_token_generic:NN }
{ \@@_execute_branches_meaning: }
\@@_def:nnnn { peek_meaning_ignore_spaces:N }
{ \@@_execute_branches_meaning: }
{ @@_token_generic:NN }
{ \@@_ignore_spaces_execute_branches: }
\@@_def:nnnn { peek_meaning_remove:N }
{ }
{ @@_token_remove_generic:NN }
{ \@@_execute_branches_meaning: }
\@@_def:nnnn { peek_meaning_remove_ignore_spaces:N }
{ \@@_execute_branches_meaning: }
{ @@_token_remove_generic:NN }
{ \@@_ignore_spaces_execute_branches: }
\group_end:
% \end{macrocode}
% \end{macro}
%
% \subsection{Decomposing a macro definition}
%
% \begin{macro}{\token_get_prefix_spec:N}
% \begin{macro}{\token_get_arg_spec:N}
% \begin{macro}{\token_get_replacement_spec:N}
% \begin{macro}[aux]{\@@_get_prefix_arg_replacement:wN}
% We sometimes want to test if a
% control sequence can be expanded to reveal a hidden
% value. However, we cannot just expand the macro blindly as it may
% have arguments and none might be present. Therefore we define
% these functions to pick either the prefix(es), the argument
% specification, or the replacement text from a macro. All of this
% information is returned as characters with catcode~$12$. If the
% token in question isn't a macro, the token \cs{scan_stop:} is
% returned instead.
% \begin{macrocode}
\exp_args:Nno \use:nn
{ \cs_new:Npn \@@_get_prefix_arg_replacement:wN #1 }
{ \tl_to_str:n { macro : } #2 -> #3 \q_stop #4 }
{ #4 {#1} {#2} {#3} }
\cs_new:Npn \token_get_prefix_spec:N #1
{
\token_if_macro:NTF #1
{
\exp_after:wN \@@_get_prefix_arg_replacement:wN
\token_to_meaning:N #1 \q_stop \use_i:nnn
}
{ \scan_stop: }
}
\cs_new:Npn \token_get_arg_spec:N #1
{
\token_if_macro:NTF #1
{
\exp_after:wN \@@_get_prefix_arg_replacement:wN
\token_to_meaning:N #1 \q_stop \use_ii:nnn
}
{ \scan_stop: }
}
\cs_new:Npn \token_get_replacement_spec:N #1
{
\token_if_macro:NTF #1
{
\exp_after:wN \@@_get_prefix_arg_replacement:wN
\token_to_meaning:N #1 \q_stop \use_iii:nnn
}
{ \scan_stop: }
}
% \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \begin{macrocode}
%</initex|package>
% \end{macrocode}
%
% \end{implementation}
%
% \PrintIndex
|