% \iffalse meta-comment % %% File: l3kernel-functions.dtx Copyright (C) 2018 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 % % https://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 development version of the bundle can be found at % % https://github.com/latex3/latex3 % % for those people who are interested. % %<*driver> \documentclass[full,kernel]{l3doc} \begin{document} \DocInput{\jobname.dtx} \end{document} % % \fi % % \title{^^A % The \pkg{l3kernel-functions} package\\ Kernel-reserved functions^^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 2018-10-17} % % \maketitle % % \begin{documentation} % % \end{documentation} % % \begin{implementation} % % \section{Internal kernel functions} % % \begin{function}{\__kernel_chk_cs_exist:N, \__kernel_chk_cs_exist:c} % \begin{syntax} % \cs{__kernel_chk_cs_exist:N} \meta{cs} % \end{syntax} % This function is only created if debugging is enabled. It checks % that \meta{cs} exists according to the criteria for % \cs{cs_if_exist_p:N}, and if not raises a kernel-level error. % \end{function} % % \begin{function}{\__kernel_chk_defined:NT} % \begin{syntax} % \cs{__kernel_chk_defined:NT} \meta{variable} \Arg{true code} % \end{syntax} % If \meta{variable} is not defined (according to % \cs{cs_if_exist:NTF}), this triggers an error, otherwise the % \meta{true code} is run. % \end{function} % % \begin{function}{\__kernel_chk_expr:nNnN} % \begin{syntax} % \cs{__kernel_chk_expr:nNnN} \Arg{expr} \meta{eval} \Arg{convert} \meta{caller} % \end{syntax} % This function is only created if debugging is enabled. By default % it is equivalent to \cs{use_i:nnnn}. When expression checking is % enabled, it leaves in the input stream the result of \cs{tex_the:D} % \meta{eval} \meta{expr} \cs{tex_relax:D} after checking that no % token was left over. If any token was not taken as part of the % expression, there is an error message displaying the result of the % evaluation as well as the \meta{caller}. For instance \meta{eval} % can be \cs{__int_eval:w} and \meta{caller} can be \cs{int_eval:n} or % \cs{int_set:Nn}. The argument \meta{convert} is empty except for mu % expressions where it is \cs{tex_mutoglue:D}, used for internal % purposes. % \end{function} % % \begin{function}{\__kernel_chk_var_exist:N} % \begin{syntax} % \cs{__kernel_chk_var_exist:N} \meta{var} % \end{syntax} % This function is only created if debugging is enabled. It checks % that \meta{var} is defined according to the criteria for % \cs{cs_if_exist_p:N}, and if not raises a kernel-level error. % \end{function} % % \begin{function}{\__kernel_chk_var_scope:NN} % \begin{syntax} % \cs{__kernel_chk_var_scope:NN} \meta{scope} \meta{var} % \end{syntax} % Checks the \meta{var} has the correct \meta{scope}, and if not % raises a kernel-level error. This function is only created if % debugging is enabled. The \meta{scope} is a single letter |l|, |g|, % |c| denoting local variables, global variables, or constants. More % precisely, if the variable name starts with a letter and an % underscore (normal \pkg{expl3} convention) the function checks that % this single letter matches the \meta{scope}. Otherwise the function % cannot know the scope \meta{var} the first time: instead, it defines % |\__debug_chk_/|\meta{var name} to store that information for the % next call. Thus, if a given \meta{var} is subject to assignments of % different scopes a kernel error will result. % \end{function} % % \begin{function}{\__kernel_chk_var_local:N, \__kernel_chk_var_global:N} % \begin{syntax} % \cs{__kernel_chk_var_local:N} \meta{var} % \cs{__kernel_chk_var_global:N} \meta{var} % \end{syntax} % Applies \cs{__kernel_chk_var_exist:N} \meta{var}, and assuming that is % true applies % \cs{__kernel_chk_var_scope:NN} \meta{scope} \meta{var}, where % \meta{scope} is |l| or~|g|. % \end{function} % % \begin{function}{\__kernel_cs_parm_from_arg_count:nnF} % \begin{syntax} % \cs{__kernel_cs_parm_from_arg_count:nnF} \Arg{follow-on} \Arg{args} \Arg{false code} % \end{syntax} % Evaluates the number of \meta{args} and leaves the \meta{follow-on} code % followed by a brace group containing the required number of primitive % parameter markers (|#1|, \emph{etc}.). If the number of \meta{args} is outside % the range $[0,9]$, the \meta{false code} is inserted \emph{instead} of % the \meta{follow-on}. % \end{function} % % \begin{function}{\__kernel_deprecation_code:nn} % \begin{syntax} % \cs{__kernel_deprecation_code:nn} \Arg{error code} \Arg{working code} % \end{syntax} % Stores both an \meta{error} and \meta{working} definition for given material % such that they can be exchanged by \cs{debug_on:} and \cs{debug_off:}. % \end{function} % % \begin{function}{\__kernel_if_debug:TF} % \begin{syntax} % \cs{__kernel_if_debug:TF} \Arg{true code} \Arg{false code} % \end{syntax} % Runs the \meta{true code} if debugging is enabled, namely only in % \LaTeXe{} package mode with one of the options % \texttt{check-declarations}, \texttt{enable-debug}, or % \texttt{log-functions}. Otherwise runs the \meta{false code}. The % |T| and |F| variants are not provided for this low-level % conditional. % \end{function} % % \begin{function}{\__kernel_debug_log:x} % \begin{syntax} % \cs{__kernel_debug_log:x} \Arg{message text} % \end{syntax} % If the \texttt{log-functions} option is active, this function writes % the \meta{message text} to the log file using \cs{iow_log:x}. % Otherwise, the \meta{message text} is ignored using \cs{use_none:n}. % This function is only created if debugging is enabled. % \end{function} % % \begin{function}[EXP]{\__kernel_exp_not:w} % \begin{syntax} % \cs{__kernel_exp_not:w} \meta{expandable tokens} \Arg{content} % \end{syntax} % Carries out expansion on the \meta{expandable tokens} before preventing % further expansion of the \meta{content} as for \cs{exp_not:n}. Typically, % the \meta{expandable tokens} will alter the nature of the \meta{content}, % \emph{i.e.}~allow it to be generated in some way. % \end{function} % % \begin{variable}{\l__kernel_expl_bool} % A boolean which records the current code syntax status: \texttt{true} if % currently inside a code environment. This variable should only be % set by \cs{ExplSyntaxOn}/\cs{ExplSyntaxOff}. % \end{variable} % % \begin{function}{\__kernel_file_missing:n} % \begin{syntax} % \cs{__kernel_file_missing:n} \Arg{name} % \end{syntax} % Expands the \meta{name} as per \cs{__kernel_file_name_sanitize:nN} then % produces an error message indicating that that file was not found. % \end{function} % % \begin{function}{\__kernel_file_name_sanitize:nN} % \begin{syntax} % \cs{__kernel_file_name_sanitize:nN} \Arg{name} \meta{str var} % \end{syntax} % For converting a \meta{name} to a string where active characters are treated % as strings. % \end{function} % % \begin{function}{\__kernel_file_input_push:n, \__kernel_file_input_pop:} % \begin{syntax} % \cs{__kernel_file_input_push:n} \Arg{name} % \cs{__kernel_file_input_pop:} % \end{syntax} % Used to push and pop data from the internal file stack: needed only % in package mode, where interfacing with the \LaTeXe{} kernel is necessary. % \end{function} % % \begin{function}[EXP]{\__kernel_int_add:nnn} % \begin{syntax} % \cs{__kernel_int_add:nnn} \Arg{integer_1} \Arg{integer_2} \Arg{integer_3} % \end{syntax} % Expands to the result of adding the three \meta{integers} (which % must be suitable input for \cs{int_eval:w}), avoiding intermediate % overflow. Overflow occurs only if the overall result is outside % $[-2^{31}+1,2^{31}-1]$. The \meta{integers} may be of the form % \cs{int_eval:w} \dots{} \cs{scan_stop:} but may be evaluated more % than once. % \end{function} % % \begin{function}{\__kernel_ior_open:Nn, \__kernel_ior_open:No} % \begin{syntax} % \cs{__kernel_ior_open:Nn} \meta{stream} \Arg{file name} % \end{syntax} % This function has identical syntax to the public version. However, % is does not take precautions against active characters in the % \meta{file name}, and it does not attempt to add a \meta{path} to % the \meta{file name}: it is therefore intended to be used by % higher-level % functions which have already fully expanded the \meta{file name} and which % need to perform multiple open or close operations. See for example the % implementation of \cs{file_get_full_name:nN}, % \end{function} % % \begin{function}{\__kernel_iow_with:Nnn} % \begin{syntax} % \cs{__kernel_iow_with:Nnn} \meta{integer} \Arg{value} \Arg{code} % \end{syntax} % If the \meta{integer} is equal to the \meta{value} then this % function simply runs the \meta{code}. Otherwise it saves the % current value of the \meta{integer}, sets it to the \meta{value}, % runs the \meta{code}, and restores the \meta{integer} to its former % value. This is used to ensure that the \tn{newlinechar} is~$10$ % when writing to a stream, which lets \cs{iow_newline:} work, and % that \tn{errorcontextlines} is $-1$ when displaying a message. % \end{function} % % \begin{function} % {\__kernel_msg_new:nnnn, \__kernel_msg_new:nnn} % \begin{syntax} % \cs{__kernel_msg_new:nnnn} \Arg{module} \Arg{message} \Arg{text} \Arg{more text} % \end{syntax} % Creates a kernel \meta{message} for a given \meta{module}. % The message is defined to first give \meta{text} and then % \meta{more text} if the user requests it. If no \meta{more text} is % available then a standard text is given instead. Within \meta{text} % and \meta{more text} four parameters (|#1| to |#4|) can be used: % these will be supplied and expanded at the time the message is used. % An error is raised if the \meta{message} already exists. % \end{function} % % \begin{function} % {\__kernel_msg_set:nnnn, \__kernel_msg_set:nnn} % \begin{syntax} % \cs{__kernel_msg_set:nnnn} \Arg{module} \Arg{message} \Arg{text} \Arg{more text} % \end{syntax} % Sets up the text for a kernel \meta{message} for a given \meta{module}. % The message is defined to first give \meta{text} and then % \meta{more text} if the user requests it. If no \meta{more text} is % available then a standard text is given instead. Within \meta{text} % and \meta{more text} four parameters (|#1| to |#4|) can be used: % these will be supplied and expanded at the time the message is used. % \end{function} % % \begin{function} % { % \__kernel_msg_fatal:nnnnnn , % \__kernel_msg_fatal:nnnnn , % \__kernel_msg_fatal:nnnn , % \__kernel_msg_fatal:nnn , % \__kernel_msg_fatal:nn , % \__kernel_msg_fatal:nnxxxx , % \__kernel_msg_fatal:nnxxx , % \__kernel_msg_fatal:nnxx , % \__kernel_msg_fatal:nnx % } % \begin{syntax} % \cs{__kernel_msg_fatal:nnnnnn} \Arg{module} \Arg{message} \Arg{arg one} \Arg{arg two} \Arg{arg three} \Arg{arg four} % \end{syntax} % Issues kernel \meta{module} error \meta{message}, passing \meta{arg one} % to \meta{arg four} to the text-creating functions. After issuing a % fatal error the \TeX{} run halts. Cannot be redirected. % \end{function} % % \begin{function} % { % \__kernel_msg_error:nnnnnn , % \__kernel_msg_error:nnnnn , % \__kernel_msg_error:nnnn , % \__kernel_msg_error:nnn , % \__kernel_msg_error:nn , % \__kernel_msg_error:nnxxxx , % \__kernel_msg_error:nnxxx , % \__kernel_msg_error:nnxx , % \__kernel_msg_error:nnx % } % \begin{syntax} % \cs{__kernel_msg_error:nnnnnn} \Arg{module} \Arg{message} \Arg{arg one} \Arg{arg two} \Arg{arg three} \Arg{arg four} % \end{syntax} % Issues kernel \meta{module} error \meta{message}, passing \meta{arg one} % to % \meta{arg four} to the text-creating functions. The error % stops processing and issues the text at the terminal. After user input, % the run continues. Cannot be redirected. % \end{function} % % \begin{function} % { % \__kernel_msg_warning:nnnnnn , % \__kernel_msg_warning:nnnnn , % \__kernel_msg_warning:nnnn , % \__kernel_msg_warning:nnn , % \__kernel_msg_warning:nn , % \__kernel_msg_warning:nnxxxx , % \__kernel_msg_warning:nnxxx , % \__kernel_msg_warning:nnxx , % \__kernel_msg_warning:nnx % } % \begin{syntax} % \cs{__kernel_msg_warning:nnnnnn} \Arg{module} \Arg{message} \Arg{arg one} \Arg{arg two} \Arg{arg three} \Arg{arg four} % \end{syntax} % Issues kernel \meta{module} warning \meta{message}, passing % \meta{arg one} to % \meta{arg four} to the text-creating functions. The warning text % is added to the log file, but the \TeX{} run is not interrupted. % \end{function} % % \begin{function} % { % \__kernel_msg_info:nnnnnn , % \__kernel_msg_info:nnnnn , % \__kernel_msg_info:nnnn , % \__kernel_msg_info:nnn , % \__kernel_msg_info:nn , % \__kernel_msg_info:nnxxxx , % \__kernel_msg_info:nnxxx , % \__kernel_msg_info:nnxx , % \__kernel_msg_info:nnx % } % \begin{syntax} % \cs{__kernel_msg_info:nnnnnn} \Arg{module} \Arg{message} \Arg{arg one} \Arg{arg two} \Arg{arg three} \Arg{arg four} % \end{syntax} % Issues kernel \meta{module} information \meta{message}, passing % \meta{arg one} to \meta{arg four} to the text-creating functions. % The information text is added to the log file. % \end{function} % % \begin{function}[EXP] % { % \__kernel_msg_expandable_error:nnnnnn, % \__kernel_msg_expandable_error:nnnnn, % \__kernel_msg_expandable_error:nnnn, % \__kernel_msg_expandable_error:nnn, % \__kernel_msg_expandable_error:nn, % \__kernel_msg_expandable_error:nnffff, % \__kernel_msg_expandable_error:nnfff, % \__kernel_msg_expandable_error:nnff, % \__kernel_msg_expandable_error:nnf, % } % \begin{syntax} % \cs{__kernel_msg_expandable_error:nnnnnn} \Arg{module} \Arg{message} \Arg{arg one} \Arg{arg two} \Arg{arg three} \Arg{arg four} % \end{syntax} % Issues an error, passing \meta{arg one} to \meta{arg four} % to the text-creating functions. The resulting string must % be much shorter than a line, otherwise it is cropped. % \end{function} % % \begin{function}{\__kernel_patch:nnNNpn} % \begin{syntax} % \cs{__kernel_patch:nnNNpn} \Arg{before} \Arg{after} % \meta{definition} \meta{function} \meta{parameters} \Arg{code} % \end{syntax} % If debugging is not enabled, this function ignores the \meta{before} % and \meta{after} code and performs the \meta{definition} with no % patching. Otherwise it replaces \meta{code} by \meta{before} % \meta{code} \meta{after} (which can involve |#1| and so on) in the % \meta{definition} that follows. The \meta{definition} must start % with \cs{cs_new:Npn} or \cs{cs_set:Npn} or \cs{cs_gset:Npn} or their % \texttt{_protected} counterparts. Other cases can be added as % needed. % \end{function} % % \begin{function}{\__kernel_patch_conditional:nNNpnn} % \begin{syntax} % \cs{__kernel_patch_conditional:nNNpnn} \Arg{before} % \meta{definition} \meta{conditional} \meta{parameters} \Arg{type} \Arg{code} % \end{syntax} % Similar to \cs{__kernel_patch:nnNNpn} for conditionals, namely % \meta{definition} must be \cs{prg_new_conditional:Npnn} or its % \texttt{_protected} counterpart. There is no \meta{after} code % because that would interfere with the action of the conditional. % \end{function} % % \begin{function}{\__kernel_patch_deprecation:nnNNpn} % \begin{syntax} % \cs{__kernel_patch_deprecation:nnNNpn} \Arg{before} \Arg{after} % \meta{definition} \meta{function}\meta{parameters} \Arg{type} \Arg{code} % \end{syntax} % Similar to \cs{__kernel_patch:nnNNpn} for deprecated functions. % \end{function} % % \begin{function} % {\__kernel_patch_args:nNNpn, \__kernel_patch_conditional_args:nNNpnn} % \begin{syntax} % \cs{__kernel_patch_args:nNNpn} \Arg{arguments} % \meta{definition} \meta{function} \meta{parameters} \Arg{code} % \end{syntax} % Like \cs{__kernel_patch:nnNNpn}, this tweaks the following % definition, but from the \enquote{inside out} (and if debugging is % not enabled, the \meta{arguments} are ignored). It replaces |#1|, % |#2| and so on in the \meta{code} of the definition as indicated by % the \meta{arguments}. More precisely, a temporary function is % defined using the \meta{definition} with the \meta{parameters} and % \meta{code}, then the result of expanding that function once in % front of the \meta{arguments} is used instead of the \meta{code} % when defining the actual function. For instance, % \begin{quote} % \cs{__kernel_patch_args:nNNpn} |{ { (#1) } }| \\ % \cs{cs_new:Npn} \cs{int_eval:n} |#1| \\ % ~~|{ \int_value:w \__int_eval:w #1 \__int_eval_end: }| % \end{quote} % would replace |#1| by |(#1)| in the definition of \cs{int_eval:n} when % debugging is enabled. This fails if the \meta{code} contains~|##|. % The \cs{__kernel_patch_conditional_args:nNNpnn} function is for use % before \cs{prg_new_conditional:Npnn} or its \texttt{_protected} % counterpart. % \end{function} % % \begin{function} % {\__kernel_patch_args:nnnNNpn, \__kernel_patch_conditional_args:nnnNNpnn} % \begin{syntax} % \cs{__kernel_patch_args:nnnNNpn} \Arg{before} \Arg{after} \Arg{arguments} % \meta{definition} \meta{function} \meta{parameters} \Arg{code} % \end{syntax} % A combination of \cs{__kernel_patch:nnNNpn} and % \cs{__kernel_patch_args:nNNpn}. % \end{function} % % \begin{variable}{\g__kernel_prg_map_int} % This integer is used by non-expandable mapping functions to track % the level of nesting in force. The functions % \cs[no-index]{\meta{type}_map_1:w}, % \cs[no-index]{\meta{type}_map_2:w}, \emph{etc.}, labelled by % \cs{g__kernel_prg_map_int} % hold functions to be mapped over various list datatypes in inline % and variable mappings. % \end{variable} % % \begin{variable}{\c__kernel_randint_max_int} % Maximal allowed argument to \cs{__kernel_randint:n}. Equal to % $2^{17}-1$. % \end{variable} % % \begin{function}{\__kernel_randint:n} % \begin{syntax} % \cs{__kernel_randint:n} \Arg{max} % \end{syntax} % Used in an integer expression this gives a pseudo-random number % between $1$ and $\meta{max}$ included. One must have % $\meta{max}\leq 2^{17}-1$. The \meta{max} must be suitable for % \cs{int_value:w} (and any \cs{int_eval:w} must be terminated by % \cs{scan_stop:} or equivalent). % \end{function} % % \begin{function}{\__kernel_randint:nn} % \begin{syntax} % \cs{__kernel_randint:nn} \Arg{min} \Arg{max} % \end{syntax} % Used in an integer expression this gives a pseudo-random number % between $\meta{min}$ and $\meta{max}$ included. The \meta{min} and % \meta{max} must be suitable for \cs{int_value:w} (and any % \cs{int_eval:w} must be terminated by \cs{scan_stop:} or % equivalent). For small ranges % $R=\meta{max}-\meta{min}+1\leq 2^{17}-1$, % $\meta{min} - 1 + \cs{__kernel_randint:n} |{|R|}|$ is faster. % \end{function} % % \begin{function}{\__kernel_register_show:N, \__kernel_register_show:c} % \begin{syntax} % \cs{__kernel_register_show:N} \meta{register} % \end{syntax} % Used to show the contents of a \TeX{} register at the terminal, formatted % such that internal parts of the mechanism are not visible. % \end{function} % % \begin{function} % {\__kernel_register_log:N, \__kernel_register_log:c} % \begin{syntax} % \cs{__kernel_register_log:N} \meta{register} % \end{syntax} % Used to write the contents of a \TeX{} register to the log file in a % form similar to \cs{__kernel_register_show:N}. % \end{function} % % \begin{function}[EXP]{\__kernel_str_to_other:n} % \begin{syntax} % \cs{__kernel_str_to_other:n} \Arg{token list} % \end{syntax} % Converts the \meta{token list} to a \meta{other string}, where % spaces have category code \enquote{other}. This function can be % \texttt{f}-expanded without fear of losing a leading space, since % spaces do not have category code $10$ in its result. It takes a % time quadratic in the character count of the string. % \end{function} % % \begin{function}[rEXP]{\__kernel_str_to_other_fast:n} % \begin{syntax} % \cs{__kernel_str_to_other_fast:n} \Arg{token list} % \end{syntax} % Same behaviour \cs{__kernel_str_to_other:n} but only restricted-expandable. % It takes a time linear in the character count of the string. % \end{function} % % \begin{function}[EXP]{\__kernel_tl_to_str:w} % \begin{syntax} % \cs{__kernel_tl_to_str:w} \meta{expandable tokens} \Arg{tokens} % \end{syntax} % Carries out expansion on the \meta{expandable tokens} before conversion of % the \meta{tokens} to a string as describe for \cs{tl_to_str:n}. Typically, % the \meta{expandable tokens} will alter the nature of the \meta{tokens}, % \emph{i.e.}~allow it to be generated in some way. This function requires % only a single expansion. % \end{function} % % \end{implementation} % % \PrintIndex