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diff --git a/Master/texmf-dist/source/latex-dev/l3kernel/l3str.dtx b/Master/texmf-dist/source/latex-dev/l3kernel/l3str.dtx new file mode 100644 index 00000000000..efc24fe8eae --- /dev/null +++ b/Master/texmf-dist/source/latex-dev/l3kernel/l3str.dtx @@ -0,0 +1,2226 @@ +% \iffalse meta-comment +% +%% File: l3str.dtx +% +% Copyright (C) 2011-2024 The LaTeX 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} +%</driver> +% \fi +% +% \title{^^A +% The \pkg{l3str} module\\ Strings^^A +% } +% +% \author{^^A +% The \LaTeX{} Project\thanks +% {^^A +% E-mail: +% \href{mailto:latex-team@latex-project.org} +% {latex-team@latex-project.org}^^A +% }^^A +% } +% +% \date{Released 2024-04-11} +% +% \maketitle +% +% \begin{documentation} +% +% \TeX{} associates each character with a category code: as such, there is no +% concept of a \enquote{string} as commonly understood in many other +% programming languages. However, there are places where we wish to manipulate +% token lists while in some sense \enquote{ignoring} category codes: this is +% done by treating token lists as strings in a \TeX{} sense. +% +% A \TeX{} string (and thus an \pkg{expl3} string) is a series of characters +% which have category code $12$ (\enquote{other}) with the exception of +% space characters which have category code $10$ (\enquote{space}). Thus +% at a technical level, a \TeX{} string is a token list with the appropriate +% category codes. In this documentation, these are simply referred to as +% strings. +% +% String variables are simply specialised token lists, but by convention +% should be named with the suffix \texttt{\ldots{}str}. Such variables +% should contain characters with category code $12$ (other), except +% spaces, which have category code $10$ (blank space). All the +% functions in this module which accept a token list argument first +% convert it to a string using \cs{tl_to_str:n} for internal processing, +% and do not treat a token list or the corresponding string +% representation differently. +% +% As a string is a subset of the more general token list, it is sometimes unclear +% when one should be used over the other. +% Use a string variable for data that isn't primarily intended for typesetting +% and for which a level of protection from unwanted expansion is suitable. +% This data type simplifies comparison of variables since there are no concerns +% about expansion of their contents. +% +% The functions \cs{cs_to_str:N}, \cs{tl_to_str:n}, \cs{tl_to_str:N} and +% \cs{token_to_str:N} (and variants) generate strings from the appropriate +% input: these are documented in \pkg{l3basics}, \pkg{l3tl} and \pkg{l3token}, +% respectively. +% +% Most expandable functions in this module come in three flavours: +% \begin{itemize} +% \item \cs[no-index]{str_\ldots{}:N}, which expect a token list or string +% variable as their argument; +% \item \cs[no-index]{str_\ldots{}:n}, taking any token list (or string) as an +% argument; +% \item \cs[no-index]{str_\ldots{}_ignore_spaces:n}, which ignores any space +% encountered during the operation: these functions are typically +% faster than those which take care of escaping spaces +% appropriately. +% \end{itemize} +% +% \section{Creating and initialising string variables} +% +% \begin{function}[added = 2015-09-18]{\str_new:N, \str_new:c} +% \begin{syntax} +% \cs{str_new:N} \meta{str~var} +% \end{syntax} +% Creates a new \meta{str~var} or raises an error if the name is +% already taken. The declaration is global. The \meta{str~var} is +% initially empty. +% \end{function} +% +% \begin{function}[added = 2015-09-18, updated = 2018-07-28] +% { +% \str_const:Nn, \str_const:NV, \str_const:Ne, +% \str_const:cn, \str_const:cV, \str_const:ce +% } +% \begin{syntax} +% \cs{str_const:Nn} \meta{str~var} \Arg{token list} +% \end{syntax} +% Creates a new constant \meta{str~var} or raises an error if the name +% is already taken. The value of the \meta{str~var} is set +% globally to the \meta{token list}, converted to a string. +% \end{function} +% +% \begin{function}[added = 2015-09-18] +% {\str_clear:N, \str_clear:c, \str_gclear:N, \str_gclear:c} +% \begin{syntax} +% \cs{str_clear:N} \meta{str~var} +% \end{syntax} +% Clears the content of the \meta{str~var}. +% \end{function} +% +% \begin{function}[added = 2015-09-18] +% { +% \str_clear_new:N, \str_clear_new:c, +% \str_gclear_new:N, \str_gclear_new:c +% } +% \begin{syntax} +% \cs{str_clear_new:N} \meta{str~var} +% \end{syntax} +% Ensures that the \meta{str~var} exists globally by applying +% \cs{str_new:N} if necessary, then applies +% \cs[index=str_clear:N]{str_(g)clear:N} to leave +% the \meta{str~var} empty. +% \end{function} +% +% \begin{function}[added = 2015-09-18] +% { +% \str_set_eq:NN, \str_set_eq:cN, \str_set_eq:Nc, \str_set_eq:cc, +% \str_gset_eq:NN, \str_gset_eq:cN, \str_gset_eq:Nc, \str_gset_eq:cc +% } +% \begin{syntax} +% \cs{str_set_eq:NN} \meta{str~var_1} \meta{str~var_2} +% \end{syntax} +% Sets the content of \meta{str~var_1} equal to that of +% \meta{str~var_2}. +% \end{function} +% +% \begin{function}[added = 2017-10-08] +% { +% \str_concat:NNN, \str_concat:ccc, +% \str_gconcat:NNN, \str_gconcat:ccc +% } +% \begin{syntax} +% \cs{str_concat:NNN} \meta{str~var_1} \meta{str~var_2} \meta{str~var_3} +% \end{syntax} +% Concatenates the content of \meta{str~var_2} and \meta{str~var_3} +% together and saves the result in \meta{str~var_1}. The \meta{str~var_2} +% is placed at the left side of the new string variable. +% The \meta{str~var_2} and \meta{str~var_3} must indeed be strings, as +% this function does not convert their contents to a string. +% \end{function} +% +% \begin{function}[EXP, pTF, added = 2015-09-18] +% {\str_if_exist:N, \str_if_exist:c} +% \begin{syntax} +% \cs{str_if_exist_p:N} \meta{str~var} +% \cs{str_if_exist:NTF} \meta{str~var} \Arg{true code} \Arg{false code} +% \end{syntax} +% Tests whether the \meta{str~var} is currently defined. This does not +% check that the \meta{str~var} really is a string. +% \end{function} +% +% \section{Adding data to string variables} +% +% \begin{function}[added = 2015-09-18, updated = 2018-07-28] +% { +% \str_set:Nn, \str_set:NV, \str_set:Ne, +% \str_set:cn, \str_set:cV, \str_set:ce, +% \str_gset:Nn, \str_gset:NV, \str_gset:Ne, +% \str_gset:cn, \str_gset:cV, \str_gset:ce +% } +% \begin{syntax} +% \cs{str_set:Nn} \meta{str var} \Arg{token list} +% \end{syntax} +% Converts the \meta{token list} to a \meta{string}, and stores the +% result in \meta{str var}. +% \end{function} +% +% \begin{function}[added = 2015-09-18, updated = 2018-07-28] +% { +% \str_put_left:Nn, \str_put_left:NV, \str_put_left:Ne, +% \str_put_left:cn, \str_put_left:cV, \str_put_left:ce, +% \str_gput_left:Nn, \str_gput_left:NV, \str_gput_left:Ne, +% \str_gput_left:cn, \str_gput_left:cV, \str_gput_left:ce +% } +% \begin{syntax} +% \cs{str_put_left:Nn} \meta{str var} \Arg{token list} +% \end{syntax} +% Converts the \meta{token list} to a \meta{string}, and prepends the +% result to \meta{str var}. The current contents of the \meta{str +% var} are not automatically converted to a string. +% \end{function} +% +% \begin{function}[added = 2015-09-18, updated = 2018-07-28] +% { +% \str_put_right:Nn, \str_put_right:NV, \str_put_right:Ne, +% \str_put_right:cn, \str_put_right:cV, \str_put_right:Ne, +% \str_gput_right:Nn, \str_gput_right:NV, \str_gput_right:Ne, +% \str_gput_right:cn, \str_gput_right:cV, \str_gput_right:ce +% } +% \begin{syntax} +% \cs{str_put_right:Nn} \meta{str var} \Arg{token list} +% \end{syntax} +% Converts the \meta{token list} to a \meta{string}, and appends the +% result to \meta{str var}. The current contents of the \meta{str +% var} are not automatically converted to a string. +% \end{function} +% +% \section{String conditionals} +% +% \begin{function}[EXP,pTF, added = 2015-09-18, updated = 2022-03-21] +% {\str_if_empty:N, \str_if_empty:c, \str_if_empty:n} +% \begin{syntax} +% \cs{str_if_empty_p:N} \meta{str~var} +% \cs{str_if_empty:NTF} \meta{str~var} \Arg{true code} \Arg{false code} +% \end{syntax} +% Tests if the \meta{string variable} is entirely empty +% (\emph{i.e.}~contains no characters at all). +% \end{function} +% +% \begin{function}[EXP,pTF, added = 2015-09-18] +% {\str_if_eq:NN, \str_if_eq:Nc, \str_if_eq:cN, \str_if_eq:cc} +% \begin{syntax} +% \cs{str_if_eq_p:NN} \meta{str~var_1} \meta{str~var_2} +% \cs{str_if_eq:NNTF} \meta{str~var_1} \meta{str~var_2} \Arg{true code} \Arg{false code} +% \end{syntax} +% Compares the content of two \meta{str variables} and +% is logically \texttt{true} if the two contain the same characters +% in the same order. See \cs{tl_if_eq:NNTF} to compare tokens +% (including their category codes) rather than characters. +% \end{function} +% +% \begin{function}[EXP,pTF, updated = 2018-06-18] +% { +% \str_if_eq:nn, \str_if_eq:Vn, \str_if_eq:on, \str_if_eq:no, +% \str_if_eq:nV, \str_if_eq:VV, \str_if_eq:vn, \str_if_eq:nv, +% \str_if_eq:ee +% } +% \begin{syntax} +% \cs{str_if_eq_p:nn} \Arg{tl_1} \Arg{tl_2} +% \cs{str_if_eq:nnTF} \Arg{tl_1} \Arg{tl_2} \Arg{true code} \Arg{false code} +% \end{syntax} +% Compares the two \meta{token lists} on a character by character +% basis (namely after converting them to strings), +% and is \texttt{true} if the two \meta{strings} contain the same +% characters in the same order. Thus for example +% \begin{verbatim} +% \str_if_eq_p:no { abc } { \tl_to_str:n { abc } } +% \end{verbatim} +% is logically \texttt{true}. See \cs{tl_if_eq:nnTF} to compare +% tokens (including their category codes) rather than characters. +% \end{function} +% +% \begin{function}[TF, added = 2017-10-08]{\str_if_in:Nn, \str_if_in:cn} +% \begin{syntax} +% \cs{str_if_in:NnTF} \meta{str~var} \Arg{token list} \Arg{true code} \Arg{false code} +% \end{syntax} +% Converts the \meta{token list} to a \meta{string} and +% tests if that \meta{string} is found in the content of the +% \meta{str~var}. +% \end{function} +% +% \begin{function}[TF, added = 2017-10-08]{\str_if_in:nn} +% \begin{syntax} +% \cs{str_if_in:nnTF} \Arg{tl_1} \Arg{tl_2} \Arg{true code} \Arg{false code} +% \end{syntax} +% Converts both \meta{token lists} to \meta{strings} and +% tests whether \meta{string_2} is found inside \meta{string_1}. +% \end{function} +% +% \begin{function}[added = 2013-07-24, updated = 2022-03-21, EXP, noTF] +% { +% \str_case:nn, \str_case:Vn, \str_case:Nn, \str_case:on, \str_case:en, +% \str_case:nV, \str_case:nv +% } +% \begin{syntax} +% \cs{str_case:nnTF} \Arg{test string} \\ +% ~~|{| \\ +% ~~~~\Arg{string case_1} \Arg{code case_1} \\ +% ~~~~\Arg{string case_2} \Arg{code case_2} \\ +% ~~~~\ldots \\ +% ~~~~\Arg{string case_n} \Arg{code case_n} \\ +% ~~|}| \\ +% ~~\Arg{true code} +% ~~\Arg{false code} +% \end{syntax} +% Compares the \meta{test string} in turn with each +% of the \meta{string case}s (all token lists are converted to strings). +% If the two are equal (as described for +% \cs{str_if_eq:nnTF}) then the associated \meta{code} is left in the +% input stream and other cases are discarded. If any of the +% cases are matched, the \meta{true code} is also inserted into the +% input stream (after the code for the appropriate case), while if none +% match then the \meta{false code} is inserted. The function +% \cs{str_case:nn}, which does nothing if there is no match, is also +% available. +% +% This set of functions performs no expansion on each +% \meta{string~case} argument, so any variable in there will be +% compared as a string. If expansion is needed in the +% \meta{string~case}s, then \cs[no-index]{str_case_e:nn(TF)} should +% be used instead. +% \end{function} +% +% \begin{function}[added = 2018-06-19, EXP, noTF] +% {\str_case_e:nn, \str_case_e:en} +% \begin{syntax} +% \cs{str_case_e:nnTF} \Arg{test string} \\ +% ~~|{| \\ +% ~~~~\Arg{string case_1} \Arg{code case_1} \\ +% ~~~~\Arg{string case_2} \Arg{code case_2} \\ +% ~~~~\ldots \\ +% ~~~~\Arg{string case_n} \Arg{code case_n} \\ +% ~~|}| \\ +% ~~\Arg{true code} +% ~~\Arg{false code} +% \end{syntax} +% Compares the full expansion of the \meta{test string} +% in turn with the full expansion of the \meta{string case}s +% (all token lists are converted to strings). If the two +% full expansions are equal (as described for \cs{str_if_eq:eeTF}) then the +% associated \meta{code} is left in the input stream +% and other cases are discarded. If any of the +% cases are matched, the \meta{true code} is also inserted into the +% input stream (after the code for the appropriate case), while if none +% match then the \meta{false code} is inserted. The function +% \cs{str_case_e:nn}, which does nothing if there is no match, is also +% available. +% In \cs[index=str_case_e:nnTF]{str_case_e:nn(TF)}, the \meta{test string} +% is expanded in each comparison, and must always yield the same result: +% for example, random numbers must not be used within this string. +% \end{function} +% +% \begin{function}[EXP, pTF, added = 2021-05-17]{\str_compare:nNn, \str_compare:eNe} +% \begin{syntax} +% \cs{str_compare_p:nNn} \Arg{tl_1} \meta{relation} \Arg{tl_2} +% \cs{str_compare:nNnTF} \Arg{tl_1} \meta{relation} \Arg{tl_2} \Arg{true code} \Arg{false code} +% \end{syntax} +% Compares the two \meta{token lists} on a character by character +% basis (namely after converting them to strings) in a lexicographic +% order according to the character codes of the characters. The +% \meta{relation} can be |<|, |=|, or~|>| and the test is +% \texttt{true} under the following conditions: +% \begin{itemize} +% \item for |<|, if the first string is earlier than the second in lexicographic order; +% \item for |=|, if the two strings have exactly the same characters; +% \item for |>|, if the first string is later than the second in lexicographic order. +% \end{itemize} +% Thus for example the following is logically \texttt{true}: +% \begin{verbatim} +% \str_compare_p:nNn { ab } < { abc } +% \end{verbatim} +% \begin{texnote} +% This is a wrapper around the \TeX{} primitive +% \cs[index=pdfstrcmp]{(pdf)strcmp}. It is meant for programming +% and not for sorting textual contents, as it simply considers +% character codes and not more elaborate considerations of grapheme +% clusters, locale, etc. +% \end{texnote} +% \end{function} +% +% \section{Mapping over strings} +% +% All mappings are done at the current group level, \emph{i.e.}~any +% local assignments made by the \meta{function} or \meta{code} discussed +% below remain in effect after the loop. +% +% \begin{function}[added = 2017-11-14, rEXP] +% {\str_map_function:nN, \str_map_function:NN, \str_map_function:cN} +% \begin{syntax} +% \cs{str_map_function:nN} \Arg{token list} \meta{function} +% \cs{str_map_function:NN} \meta{str~var} \meta{function} +% \end{syntax} +% Converts the \meta{token list} to a \meta{string} then +% applies \meta{function} to every \meta{character} in the +% \meta{string} including spaces. +% \end{function} +% +% \begin{function}[added = 2017-11-14] +% {\str_map_inline:nn, \str_map_inline:Nn, \str_map_inline:cn} +% \begin{syntax} +% \cs{str_map_inline:nn} \Arg{token list} \Arg{inline function} +% \cs{str_map_inline:Nn} \meta{str~var} \Arg{inline function} +% \end{syntax} +% Converts the \meta{token list} to a \meta{string} then +% applies the \meta{inline function} to every \meta{character} in the +% \meta{str~var} including spaces. +% The \meta{inline function} should consist of code which +% receives the \meta{character} as |#1|. +% \end{function} +% +% \begin{function}[rEXP, added = 2021-05-05] +% {\str_map_tokens:nn, \str_map_tokens:Nn, \str_map_tokens:cn} +% \begin{syntax} +% \cs{str_map_tokens:nn} \Arg{token list} \Arg{code} +% \cs{str_map_tokens:Nn} \meta{str~var} \Arg{code} +% \end{syntax} +% Converts the \meta{token list} to a \meta{string} then applies +% \meta{code} to every \meta{character} in the \meta{string} including +% spaces. The \meta{code} receives each character as a trailing brace +% group. This is equivalent to \cs{str_map_function:nN} if the +% \meta{code} consists of a single function. +% \end{function} +% +% \begin{function}[added = 2017-11-14] +% {\str_map_variable:nNn, \str_map_variable:NNn, \str_map_variable:cNn} +% \begin{syntax} +% \cs{str_map_variable:nNn} \Arg{token list} \meta{variable} \Arg{code} +% \cs{str_map_variable:NNn} \meta{str~var} \meta{variable} \Arg{code} +% \end{syntax} +% Converts the \meta{token list} to a \meta{string} then stores each +% \meta{character} in the \meta{string} (including spaces) in turn in +% the (string or token list) \meta{variable} and applies the +% \meta{code}. The \meta{code} will usually make use of the +% \meta{variable}, but this is not enforced. The assignments to the +% \meta{variable} are local. Its value after the loop is the last +% \meta{character} in the \meta{string}, or its original value if the +% \meta{string} is empty. See also \cs{str_map_inline:Nn}. +% \end{function} +% +% \begin{function}[added = 2017-10-08, rEXP]{\str_map_break:} +% \begin{syntax} +% \cs{str_map_break:} +% \end{syntax} +% Used to terminate a \cs[no-index]{str_map_\ldots} function before all +% characters in the \meta{string} have been processed. This +% normally takes place within a conditional statement, for example +% \begin{verbatim} +% \str_map_inline:Nn \l_my_str +% { +% \str_if_eq:nnT { #1 } { bingo } { \str_map_break: } +% % Do something useful +% } +% \end{verbatim} +% See also \cs{str_map_break:n}. +% Use outside of a \cs[no-index]{str_map_\ldots} scenario leads to low +% level \TeX{} errors. +% \begin{texnote} +% When the mapping is broken, additional tokens may be inserted +% before continuing with the +% code that follows the loop. +% This depends on the design of the mapping function. +% \end{texnote} +% \end{function} +% +% \begin{function}[added = 2017-10-08, rEXP]{\str_map_break:n} +% \begin{syntax} +% \cs{str_map_break:n} \Arg{code} +% \end{syntax} +% Used to terminate a \cs[no-index]{str_map_\ldots} function before all +% characters in the \meta{string} have been processed, inserting +% the \meta{code} after the mapping has ended. This +% normally takes place within a conditional statement, for example +% \begin{verbatim} +% \str_map_inline:Nn \l_my_str +% { +% \str_if_eq:nnT { #1 } { bingo } +% { \str_map_break:n { <code> } } +% % Do something useful +% } +% \end{verbatim} +% Use outside of a \cs[no-index]{str_map_\ldots} scenario leads to low +% level \TeX{} errors. +% \begin{texnote} +% When the mapping is broken, additional tokens may be inserted +% before the \meta{code} is +% inserted into the input stream. +% This depends on the design of the mapping function. +% \end{texnote} +% \end{function} +% +% \section{Working with the content of strings} +% +% \begin{function}[EXP, added = 2015-09-18]{\str_use:N, \str_use:c} +% \begin{syntax} +% \cs{str_use:N} \meta{str~var} +% \end{syntax} +% Recovers the content of a \meta{str~var} and places it +% directly in the input stream. An error is raised if the variable +% does not exist or if it is invalid. Note that it is possible to use +% a \meta{str} directly without an accessor function. +% \end{function} +% +% \begin{function}[EXP, added = 2015-09-18] +% {\str_count:N, \str_count:c, \str_count:n, \str_count_ignore_spaces:n} +% \begin{syntax} +% \cs{str_count:n} \Arg{token list} +% \end{syntax} +% Leaves in the input stream the number of characters in the string +% representation of \meta{token list}, as an integer denotation. The +% functions differ in their treatment of spaces. In the case of +% \cs{str_count:N} and \cs{str_count:n}, all characters including +% spaces are counted. The \cs{str_count_ignore_spaces:n} function +% leaves the number of non-space characters in the input stream. +% \end{function} +% +% \begin{function}[EXP, added = 2015-09-18] +% {\str_count_spaces:N, \str_count_spaces:c, \str_count_spaces:n} +% \begin{syntax} +% \cs{str_count_spaces:n} \Arg{token list} +% \end{syntax} +% Leaves in the input stream the number of space characters in the +% string representation of \meta{token list}, as an integer +% denotation. Of course, this function has no \texttt{_ignore_spaces} +% variant. +% \end{function} +% +% \begin{function}[EXP, added = 2015-09-18] +% {\str_head:N, \str_head:c, \str_head:n, \str_head_ignore_spaces:n} +% \begin{syntax} +% \cs{str_head:n} \Arg{token list} +% \end{syntax} +% Converts the \meta{token list} into a \meta{string}. The first +% character in the \meta{string} is then left in the input stream, +% with category code \enquote{other}. The functions differ if the +% first character is a space: \cs{str_head:N} and \cs{str_head:n} +% return a space token with category code~$10$ (blank space), while +% the \cs{str_head_ignore_spaces:n} function ignores this space +% character and leaves the first non-space character in the input +% stream. If the \meta{string} is empty (or only contains spaces in +% the case of the \texttt{_ignore_spaces} function), then nothing is +% left on the input stream. +% \end{function} +% +% \begin{function}[EXP, added = 2015-09-18] +% {\str_tail:N, \str_tail:c, \str_tail:n, \str_tail_ignore_spaces:n} +% \begin{syntax} +% \cs{str_tail:n} \Arg{token list} +% \end{syntax} +% Converts the \meta{token list} to a \meta{string}, removes the first +% character, and leaves the remaining characters (if any) in the input +% stream, with category codes $12$ and $10$ (for spaces). The +% functions differ in the case where the first character is a space: +% \cs{str_tail:N} and \cs{str_tail:n} only trim that space, while +% \cs{str_tail_ignore_spaces:n} removes the first non-space character +% and any space before it. If the \meta{token list} is empty (or +% blank in the case of the \texttt{_ignore_spaces} variant), then +% nothing is left on the input stream. +% \end{function} +% +% \begin{function}[EXP, added = 2015-09-18] +% {\str_item:Nn, \str_item:nn, \str_item_ignore_spaces:nn} +% \begin{syntax} +% \cs{str_item:nn} \Arg{token list} \Arg{integer expression} +% \end{syntax} +% Converts the \meta{token list} to a \meta{string}, and leaves in the +% input stream the character in position \meta{integer expression} of +% the \meta{string}, starting at $1$ for the first (left-most) +% character. In the case of \cs{str_item:Nn} and \cs{str_item:nn}, +% all characters including spaces are taken into account. The +% \cs{str_item_ignore_spaces:nn} function skips spaces when counting +% characters. If the \meta{integer expression} is negative, +% characters are counted from the end of the \meta{string}. Hence, +% $-1$ is the right-most character, \emph{etc.} +% \end{function} +% +% \begin{function}[EXP, added = 2015-09-18] +% { +% \str_range:Nnn, \str_range:cnn, \str_range:nnn, +% \str_range_ignore_spaces:nnn +% } +% \begin{syntax} +% \cs{str_range:nnn} \Arg{token list} \Arg{start index} \Arg{end index} +% \end{syntax} +% Converts the \meta{token list} to a \meta{string}, and leaves in the +% input stream the characters from the \meta{start index} to the +% \meta{end index} inclusive. Spaces are preserved and counted as items +% (contrast this with \cs{tl_range:nnn} where spaces are not counted as +% items and are possibly discarded from the output). +% +% Here \meta{start index} and \meta{end index} should be integer denotations. +% For describing in detail the functions' behavior, let $m$ and $n$ be the start +% and end index respectively. If either is $0$, the result is empty. A positive +% index means `start counting from the left end', a negative index means +% `start counting from the right end'. Let $l$ be the count of the token list. +% +% The \emph{actual start point} is determined as $M=m$ if~$m>0$ and as $M=l+m+1$ +% if~$m<0$. Similarly the \emph{actual end point} is $N=n$ if~$n>0$ and $N=l+n+1$ +% if~$n<0$. If $M>N$, the result is empty. Otherwise it consists of all items from +% position $M$ to position $N$ inclusive; for the purpose of this rule, we can +% imagine that the token list extends at infinity on either side, with void items +% at positions $s$ for $s\le0$ or $s>l$. +% For instance, +% \begin{verbatim} +% \iow_term:e { \str_range:nnn { abcdef } { 2 } { 5 } } +% \iow_term:e { \str_range:nnn { abcdef } { -4 } { -1 } } +% \iow_term:e { \str_range:nnn { abcdef } { -2 } { -1 } } +% \iow_term:e { \str_range:nnn { abcdef } { 0 } { -1 } } +% \end{verbatim} +% prints \texttt{bcde}, \texttt{cdef}, \texttt{ef}, and an empty +% line to the terminal. The \meta{start index} must always be smaller than +% or equal to the \meta{end index}: if this is not the case then no output +% is generated. Thus +% \begin{verbatim} +% \iow_term:e { \str_range:nnn { abcdef } { 5 } { 2 } } +% \iow_term:e { \str_range:nnn { abcdef } { -1 } { -4 } } +% \end{verbatim} +% both yield empty strings. +% \end{function} +% +% ^^A If this stays in the same {function} environment, we get a really +% ^^A awful page break. Perhaps we should add a way to allow a page break +% ^^A in a function environment... +% The behavior of \cs{str_range_ignore_spaces:nnn} is similar, but spaces +% are removed before starting the job. The input +% \begin{verbatim} +% \iow_term:e { \str_range:nnn { abcdefg } { 2 } { 5 } } +% \iow_term:e { \str_range:nnn { abcdefg } { 2 } { -3 } } +% \iow_term:e { \str_range:nnn { abcdefg } { -6 } { 5 } } +% \iow_term:e { \str_range:nnn { abcdefg } { -6 } { -3 } } +% +% \iow_term:e { \str_range:nnn { abc~efg } { 2 } { 5 } } +% \iow_term:e { \str_range:nnn { abc~efg } { 2 } { -3 } } +% \iow_term:e { \str_range:nnn { abc~efg } { -6 } { 5 } } +% \iow_term:e { \str_range:nnn { abc~efg } { -6 } { -3 } } +% +% \iow_term:e { \str_range_ignore_spaces:nnn { abcdefg } { 2 } { 5 } } +% \iow_term:e { \str_range_ignore_spaces:nnn { abcdefg } { 2 } { -3 } } +% \iow_term:e { \str_range_ignore_spaces:nnn { abcdefg } { -6 } { 5 } } +% \iow_term:e { \str_range_ignore_spaces:nnn { abcdefg } { -6 } { -3 } } +% +% \iow_term:e { \str_range_ignore_spaces:nnn { abcd~efg } { 2 } { 5 } } +% \iow_term:e { \str_range_ignore_spaces:nnn { abcd~efg } { 2 } { -3 } } +% \iow_term:e { \str_range_ignore_spaces:nnn { abcd~efg } { -6 } { 5 } } +% \iow_term:e { \str_range_ignore_spaces:nnn { abcd~efg } { -6 } { -3 } } +% \end{verbatim} +% will print four instances of |bcde|, four instances of |bc e| and eight +% instances of |bcde|. +% ^^A\end{function} +% +% \section{Modifying string variables} +% +% \begin{function}[added = 2017-10-08] +% { +% \str_replace_once:Nnn, \str_replace_once:cnn, +% \str_greplace_once:Nnn, \str_greplace_once:cnn +% } +% \begin{syntax} +% \cs{str_replace_once:Nnn} \meta{str~var} \Arg{old} \Arg{new} +% \end{syntax} +% Converts the \meta{old} and \meta{new} token lists to strings, then +% replaces the first (leftmost) occurrence of \meta{old string} in the +% \meta{str~var} with \meta{new string}. +% \end{function} +% +% \begin{function}[added = 2017-10-08] +% { +% \str_replace_all:Nnn, \str_replace_all:cnn, +% \str_greplace_all:Nnn, \str_greplace_all:cnn +% } +% \begin{syntax} +% \cs{str_replace_all:Nnn} \meta{str~var} \Arg{old} \Arg{new} +% \end{syntax} +% Converts the \meta{old} and \meta{new} token lists to strings, then +% replaces all occurrences of \meta{old string} in the +% \meta{str~var} with \meta{new string}. +% As this function +% operates from left to right, the pattern \meta{old string} +% may remain after the replacement (see \cs{str_remove_all:Nn} +% for an example). +% \end{function} +% +% \begin{function}[added = 2017-10-08] +% { +% \str_remove_once:Nn, \str_remove_once:cn, +% \str_gremove_once:Nn, \str_gremove_once:cn +% } +% \begin{syntax} +% \cs{str_remove_once:Nn} \meta{str~var} \Arg{token list} +% \end{syntax} +% Converts the \meta{token list} to a \meta{string} then +% removes the first (leftmost) occurrence of \meta{string} from the +% \meta{str~var}. +% \end{function} +% +% \begin{function}[added = 2017-10-08] +% { +% \str_remove_all:Nn, \str_remove_all:cn, +% \str_gremove_all:Nn, \str_gremove_all:cn +% } +% \begin{syntax} +% \cs{str_remove_all:Nn} \meta{str~var} \Arg{token list} +% \end{syntax} +% Converts the \meta{token list} to a \meta{string} then +% removes all occurrences of \meta{string} from the +% \meta{str~var}. +% As this function +% operates from left to right, the pattern \meta{string} +% may remain after the removal, for instance, +% \begin{quote} +% \cs{str_set:Nn} \cs{l_tmpa_str} |{abbccd}| +% \cs{str_remove_all:Nn} \cs{l_tmpa_str} |{bc}| +% \end{quote} +% results in \cs{l_tmpa_str} containing \texttt{abcd}. +% \end{function} +% +% \section{String manipulation} +% +% \begin{function}[EXP, added = 2019-11-26] +% { +% \str_lowercase:n, \str_lowercase:f, +% \str_uppercase:n, \str_uppercase:f +% } +% \begin{syntax} +% \cs{str_lowercase:n} \Arg{tokens} +% \cs{str_uppercase:n} \Arg{tokens} +% \end{syntax} +% Converts the input \meta{tokens} to their string representation, as +% described for \cs{tl_to_str:n}, and then to the lower or upper +% case representation using a one-to-one mapping as described by the +% Unicode Consortium file |UnicodeData.txt|. +% +% These functions are intended for case changing programmatic data in +% places where upper/lower case distinctions are meaningful. One example +% would be automatically generating a function name from user input where +% some case changing is needed. In this situation the input is programmatic, +% not textual, case does have meaning and a language-independent one-to-one +% mapping is appropriate. For example +% \begin{verbatim} +% \cs_new_protected:Npn \myfunc:nn #1#2 +% { +% \cs_set_protected:cpn +% { +% user +% \str_uppercase:f { \tl_head:n {#1} } +% \str_lowercase:f { \tl_tail:n {#1} } +% } +% { #2 } +% } +% \end{verbatim} +% would be used to generate a function with an auto-generated name consisting +% of the upper case equivalent of the supplied name followed by the lower +% case equivalent of the rest of the input. +% +% These functions should \emph{not} be used for +% \begin{itemize} +% \item Caseless comparisons: use \cs{str_casefold:n} for this +% situation (case folding is distinct from lower casing). +% \item Case changing text for typesetting: see the +% \cs[index=text_lowercase:n]{text_lowercase:n(n)}, +% \cs[index=text_uppercase:n]{text_uppercase:n(n)} and +% \cs[index=text_titlecase_all:n]{text_titlecase_(all|once):n(n)} functions which +% correctly deal with context-dependence and other factors appropriate +% to text case changing. +% \end{itemize} +% \end{function} +% +% \begin{function}[EXP, added = 2022-10-16] +% {\str_casefold:n, \str_casefold:V} +% \begin{syntax} +% \cs{str_casefold:n} \Arg{tokens} +% \end{syntax} +% Converts the input \meta{tokens} to their string representation, as +% described for \cs{tl_to_str:n}, and then folds the case of the resulting +% \meta{string} to remove case information. The result of this process is +% left in the input stream. +% +% String folding is a process used for material such as identifiers rather +% than for \enquote{text}. The folding provided by \cs{str_casefold:n} +% follows the mappings provided by the \href{http://www.unicode.org}^^A +% {Unicode Consortium}, who +% \href{http://www.unicode.org/faq/casemap_charprop.html#2}{state}: +% \begin{quote} +% Case folding is primarily used for caseless comparison of text, such +% as identifiers in a computer program, rather than actual text +% transformation. Case folding in Unicode is based on the lowercase +% mapping, but includes additional changes to the source text to help make +% it language-insensitive and consistent. As a result, case-folded text +% should be used solely for internal processing and generally should not be +% stored or displayed to the end user. +% \end{quote} +% The folding approach implemented by \cs{str_casefold:n} follows the +% \enquote{full} scheme defined by the Unicode Consortium +% (\emph{e.g.}~\SS folds to \texttt{SS}). As case-folding is +% a language-insensitive process, there is no special treatment of +% Turkic input (\emph{i.e.}~\texttt{I} always folds to \texttt{i} and +% not to \texttt{\i}). +% \end{function} +% +% \begin{function}[added = 2023-05-19, EXP]{\str_mdfive_hash:n, \str_mdfive_hash:e} +% \begin{syntax} +% \cs{str_mdfive_hash:n} \Arg{tl} +% \end{syntax} +% Expands to the MD5 sum generated from the \meta{tl}, which is converted +% to a \meta{string} as described for \cs{tl_to_str:n}. +% \end{function} +% +% \section{Viewing strings} +% +% \begin{function}[added = 2015-09-18, updated = 2021-04-29] +% {\str_show:N, \str_show:c, \str_show:n} +% \begin{syntax} +% \cs{str_show:N} \meta{str~var} +% \end{syntax} +% Displays the content of the \meta{str~var} on the terminal. +% \end{function} +% +% \begin{function}[added = 2019-02-15, updated = 2021-04-29] +% {\str_log:N, \str_log:c, \str_log:n} +% \begin{syntax} +% \cs{str_log:N} \meta{str~var} +% \end{syntax} +% Writes the content of the \meta{str~var} in the log file. +% \end{function} +% +% \section{Constant strings} +% +% \begin{variable}[added = 2015-09-19, updated = 2020-12-22, module = str] +% { +% \c_ampersand_str, +% \c_atsign_str, +% \c_backslash_str, +% \c_left_brace_str, +% \c_right_brace_str, +% \c_circumflex_str, +% \c_colon_str, +% \c_dollar_str, +% \c_hash_str, +% \c_percent_str, +% \c_tilde_str, +% \c_underscore_str, +% \c_zero_str +% } +% Constant strings, containing a single character token, with category +% code $12$. +% \end{variable} +% +% \begin{variable}[added = 2023-12-07]{\c_empty_str} +% Constant that is always empty. +% \end{variable} +% +% \section{Scratch strings} +% +% \begin{variable}{\l_tmpa_str, \l_tmpb_str} +% Scratch strings for local assignment. These are never used by +% the kernel code, and so are safe for use with any \LaTeX3-defined +% function. However, they may be overwritten by other non-kernel +% code and so should only be used for short-term storage. +% \end{variable} +% +% \begin{variable}{\g_tmpa_str, \g_tmpb_str} +% Scratch strings for global assignment. These are never used by +% the kernel code, and so are safe for use with any \LaTeX3-defined +% function. However, they may be overwritten by other non-kernel +% code and so should only be used for short-term storage. +% \end{variable} +% +% \end{documentation} +% +% \begin{implementation} +% +% \section{\pkg{l3str} implementation} +% +% \begin{macrocode} +%<*package> +% \end{macrocode} +% +% \begin{macrocode} +%<@@=str> +% \end{macrocode} +% +% \subsection{Internal auxiliaries} +% +% \begin{variable}{\s_@@_mark,\s_@@_stop} +% Internal scan marks. +% \begin{macrocode} +\scan_new:N \s_@@_mark +\scan_new:N \s_@@_stop +% \end{macrocode} +% \end{variable} +% +% \begin{macro}[EXP]{ +% \@@_use_none_delimit_by_s_stop:w, +% \@@_use_i_delimit_by_s_stop:nw +% } +% Functions to gobble up to a scan mark. +% \begin{macrocode} +\cs_new:Npn \@@_use_none_delimit_by_s_stop:w #1 \s_@@_stop { } +\cs_new:Npn \@@_use_i_delimit_by_s_stop:nw #1 #2 \s_@@_stop {#1} +% \end{macrocode} +% \end{macro} +% +% \begin{variable}{\q_@@_recursion_tail,\q_@@_recursion_stop} +% Internal recursion quarks. +% \begin{macrocode} +\quark_new:N \q_@@_recursion_tail +\quark_new:N \q_@@_recursion_stop +% \end{macrocode} +% \end{variable} +% +% \begin{macro}[EXP]{ +% \@@_if_recursion_tail_break:NN, +% \@@_if_recursion_tail_stop_do:Nn +% } +% Functions to query recursion quarks. +% \begin{macrocode} +\__kernel_quark_new_test:N \@@_if_recursion_tail_break:NN +\__kernel_quark_new_test:N \@@_if_recursion_tail_stop_do:Nn +% \end{macrocode} +% \end{macro} +% +% \subsection{Creating and setting string variables} +% +% \begin{macro} +% { +% \str_new:N, \str_new:c, +% \str_use:N, \str_use:c, +% \str_clear:N, \str_clear:c, +% \str_gclear:N,\str_gclear:c, +% \str_clear_new:N, \str_clear_new:c, +% \str_gclear_new:N, \str_gclear_new:c +% } +% \begin{macro} +% { +% \str_set_eq:NN, \str_set_eq:cN, \str_set_eq:Nc, \str_set_eq:cc, +% \str_gset_eq:NN, \str_gset_eq:cN, \str_gset_eq:Nc, \str_gset_eq:cc +% } +% \begin{macro} +% {\str_concat:NNN, \str_concat:ccc, \str_gconcat:NNN, \str_gconcat:ccc} +% A string is simply a token list. The full mapping system isn't set up +% yet so do things by hand. +% \begin{macrocode} +\group_begin: + \cs_set_protected:Npn \@@_tmp:n #1 + { + \tl_if_blank:nF {#1} + { + \cs_new_eq:cc { str_ #1 :N } { tl_ #1 :N } + \exp_args:Nc \cs_generate_variant:Nn { str_ #1 :N } { c } + \@@_tmp:n + } + } + \@@_tmp:n + { new } + { use } + { clear } + { gclear } + { clear_new } + { gclear_new } + { } +\group_end: +\cs_new_eq:NN \str_set_eq:NN \tl_set_eq:NN +\cs_new_eq:NN \str_gset_eq:NN \tl_gset_eq:NN +\cs_generate_variant:Nn \str_set_eq:NN { c , Nc , cc } +\cs_generate_variant:Nn \str_gset_eq:NN { c , Nc , cc } +\cs_new_eq:NN \str_concat:NNN \tl_concat:NNN +\cs_new_eq:NN \str_gconcat:NNN \tl_gconcat:NNN +\cs_generate_variant:Nn \str_concat:NNN { ccc } +\cs_generate_variant:Nn \str_gconcat:NNN { ccc } +% \end{macrocode} +% \end{macro} +% \end{macro} +% \end{macro} +% +% \begin{macro} +% { +% \str_set:Nn, \str_set:NV, \str_set:Ne, \str_set:Nx, +% \str_set:cn, \str_set:cV, \str_set:ce, \str_set:cx, +% \str_gset:Nn, \str_gset:NV, \str_gset:Ne, \str_gset:Nx, +% \str_gset:cn, \str_gset:cV, \str_gset:ce, \str_gset:cx, +% \str_const:Nn, \str_const:NV, \str_const:Ne, \str_const:Nx, +% \str_const:cn, \str_const:cV, \str_const:ce, \str_const:cx, +% \str_put_left:Nn, \str_put_left:NV, \str_put_left:Ne, \str_put_left:Nx, +% \str_put_left:cn, \str_put_left:cV, \str_put_left:ce, \str_put_left:cx, +% \str_gput_left:Nn, \str_gput_left:NV, \str_gput_left:Ne, \str_gput_left:Nx, +% \str_gput_left:cn, \str_gput_left:cV, \str_gput_left:ce, \str_gput_left:cx, +% \str_put_right:Nn, \str_put_right:NV, \str_put_right:Ne, \str_put_right:Nx, +% \str_put_right:cn, \str_put_right:cV, \str_put_right:ce, \str_put_right:cx, +% \str_gput_right:Nn, \str_gput_right:NV, \str_gput_right:Ne, \str_gput_right:Nx, +% \str_gput_right:cn, \str_gput_right:cV, \str_gput_right:ce, \str_gput_right:cx +% } +% Similar to corresponding \pkg{l3tl} base functions, except that +% \cs{__kernel_exp_not:w} is replaced with \cs{__kernel_tl_to_str:w}. +% Just like token list, string constants use \cs{cs_gset_nopar:Npe} +% instead of \cs{__kernel_tl_gset:Nx} so that the scope checking for +% |c| is applied when \pkg{l3debug} is used. +% To maintain backward compatibility, in +% \cs[index=str_put_left:Nn]{str_(g)put_left:Nn} and +% \cs[index=str_put_right:Nn]{str_(g)put_right:Nn}, +% contents of string variables are wrapped in \cs{__kernel_exp_not:w} +% to prevent further expansion. +% \begin{macrocode} +\cs_new_protected:Npn \str_set:Nn #1#2 + { \__kernel_tl_set:Nx #1 { \__kernel_tl_to_str:w {#2} } } +\cs_gset_protected:Npn \str_gset:Nn #1#2 + { \__kernel_tl_gset:Nx #1 { \__kernel_tl_to_str:w {#2} } } +\cs_new_protected:Npn \str_const:Nn #1#2 + { + \__kernel_chk_if_free_cs:N #1 + \cs_gset_nopar:Npe #1 { \__kernel_tl_to_str:w {#2} } + } +\cs_new_protected:Npn \str_put_left:Nn #1#2 + { + \__kernel_tl_set:Nx #1 + { \__kernel_tl_to_str:w {#2} \__kernel_exp_not:w \exp_after:wN {#1} } + } +\cs_new_protected:Npn \str_gput_left:Nn #1#2 + { + \__kernel_tl_gset:Nx #1 + { \__kernel_tl_to_str:w {#2} \__kernel_exp_not:w \exp_after:wN {#1} } + } +\cs_new_protected:Npn \str_put_right:Nn #1#2 + { + \__kernel_tl_set:Nx #1 + { \__kernel_exp_not:w \exp_after:wN {#1} \__kernel_tl_to_str:w {#2} } + } +\cs_new_protected:Npn \str_gput_right:Nn #1#2 + { + \__kernel_tl_gset:Nx #1 + { \__kernel_exp_not:w \exp_after:wN {#1} \__kernel_tl_to_str:w {#2} } + } +\cs_generate_variant:Nn \str_set:Nn { NV , Ne , Nx , c , cV , ce , cx } +\cs_generate_variant:Nn \str_gset:Nn { NV , Ne , Nx , c , cV , ce , cx } +\cs_generate_variant:Nn \str_const:Nn { NV , Ne , Nx , c , cV , ce , cx } +\cs_generate_variant:Nn \str_put_left:Nn { NV , Ne , Nx , c , cV , ce , cx } +\cs_generate_variant:Nn \str_gput_left:Nn { NV , Ne , Nx , c , cV , ce , cx } +\cs_generate_variant:Nn \str_put_right:Nn { NV , Ne , Nx , c , cV , ce , cx } +\cs_generate_variant:Nn \str_gput_right:Nn { NV , Ne , Nx , c , cV , ce , cx } +% \end{macrocode} +% \end{macro} +% +% \subsection{Modifying string variables} +% +% \begin{macro} +% { +% \str_replace_all:Nnn, \str_replace_all:cnn, +% \str_greplace_all:Nnn, \str_greplace_all:cnn, +% \str_replace_once:Nnn, \str_replace_once:cnn, +% \str_greplace_once:Nnn, \str_greplace_once:cnn +% } +% \begin{macro}{\@@_replace:NNNnn} +% \begin{macro}{\@@_replace_aux:NNNnnn} +% \begin{macro}{\@@_replace_next:w} +% Start by applying \cs{tl_to_str:n} to convert the old and new token +% lists to strings, and also apply \cs{tl_to_str:N} to avoid any +% issues if we are fed a token list variable. Then the code is a much +% simplified version of the token list code because neither the +% delimiter nor the replacement can contain macro parameters or +% braces. The delimiter \cs{s_@@_mark} cannot appear in the string to +% edit so it is used in all cases. Some |e|-expansion is unnecessary. +% There is no need to avoid losing braces nor to protect against +% expansion. The ending code is much simplified and does not need to +% hide in braces. +% \begin{macrocode} +\cs_new_protected:Npn \str_replace_once:Nnn + { \@@_replace:NNNnn \prg_do_nothing: \__kernel_tl_set:Nx } +\cs_new_protected:Npn \str_greplace_once:Nnn + { \@@_replace:NNNnn \prg_do_nothing: \__kernel_tl_gset:Nx } +\cs_new_protected:Npn \str_replace_all:Nnn + { \@@_replace:NNNnn \@@_replace_next:w \__kernel_tl_set:Nx } +\cs_new_protected:Npn \str_greplace_all:Nnn + { \@@_replace:NNNnn \@@_replace_next:w \__kernel_tl_gset:Nx } +\cs_generate_variant:Nn \str_replace_once:Nnn { c } +\cs_generate_variant:Nn \str_greplace_once:Nnn { c } +\cs_generate_variant:Nn \str_replace_all:Nnn { c } +\cs_generate_variant:Nn \str_greplace_all:Nnn { c } +\cs_new_protected:Npn \@@_replace:NNNnn #1#2#3#4#5 + { + \tl_if_empty:nTF {#4} + { + \msg_error:nne { kernel } { empty-search-pattern } {#5} + } + { + \use:e + { + \exp_not:n { \@@_replace_aux:NNNnnn #1 #2 #3 } + { \tl_to_str:N #3 } + { \tl_to_str:n {#4} } { \tl_to_str:n {#5} } + } + } + } +\cs_new_protected:Npn \@@_replace_aux:NNNnnn #1#2#3#4#5#6 + { + \cs_set:Npn \@@_replace_next:w ##1 #5 { ##1 #6 #1 } + #2 #3 + { + \@@_replace_next:w + #4 + \@@_use_none_delimit_by_s_stop:w + #5 + \s_@@_stop + } + } +\cs_new_eq:NN \@@_replace_next:w ? +% \end{macrocode} +% \end{macro} +% \end{macro} +% \end{macro} +% \end{macro} +% +% \begin{macro}{\str_remove_once:Nn, \str_remove_once:cn} +% \begin{macro}{\str_gremove_once:Nn, \str_gremove_once:cn} +% Removal is just a special case of replacement. +% \begin{macrocode} +\cs_new_protected:Npn \str_remove_once:Nn #1#2 + { \str_replace_once:Nnn #1 {#2} { } } +\cs_new_protected:Npn \str_gremove_once:Nn #1#2 + { \str_greplace_once:Nnn #1 {#2} { } } +\cs_generate_variant:Nn \str_remove_once:Nn { c } +\cs_generate_variant:Nn \str_gremove_once:Nn { c } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \begin{macro}{\str_remove_all:Nn, \str_remove_all:cn} +% \begin{macro}{\str_gremove_all:Nn, \str_gremove_all:cn} +% Removal is just a special case of replacement. +% \begin{macrocode} +\cs_new_protected:Npn \str_remove_all:Nn #1#2 + { \str_replace_all:Nnn #1 {#2} { } } +\cs_new_protected:Npn \str_gremove_all:Nn #1#2 + { \str_greplace_all:Nnn #1 {#2} { } } +\cs_generate_variant:Nn \str_remove_all:Nn { c } +\cs_generate_variant:Nn \str_gremove_all:Nn { c } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \subsection{String comparisons} +% +% \begin{macro}[pTF, EXP] +% { +% \str_if_empty:N, \str_if_empty:c, \str_if_empty:n, +% \str_if_exist:N, \str_if_exist:c +% } +% More copy-paste! +% \begin{macrocode} +\prg_new_eq_conditional:NNn \str_if_exist:N \tl_if_exist:N + { p , T , F , TF } +\prg_new_eq_conditional:NNn \str_if_exist:c \tl_if_exist:c + { p , T , F , TF } +\prg_new_eq_conditional:NNn \str_if_empty:N \tl_if_empty:N + { p , T , F , TF } +\prg_new_eq_conditional:NNn \str_if_empty:c \tl_if_empty:c + { p , T , F , TF } +\prg_new_eq_conditional:NNn \str_if_empty:n \tl_if_empty:n + { p , T , F , TF } +% \end{macrocode} +% \end{macro} +% +% \begin{macro}[EXP]{\@@_if_eq:nn} +% String comparisons rely on the primitive \tn[index=pdfstrcmp]{(pdf)strcmp}, +% so we define a new name for it. +% \begin{macrocode} +\cs_new_eq:NN \@@_if_eq:nn \tex_strcmp:D +% \end{macrocode} +% \end{macro} +% +% \begin{macro}[pTF, EXP]{\str_compare:nNn, \str_compare:eNe} +% Simply rely on \cs{@@_if_eq:nn}, which expands to |-1|, |0| +% or~|1|. The |ee| version is created directly because it is more efficient. +% \begin{macrocode} +\prg_new_conditional:Npnn \str_compare:nNn #1#2#3 { p , T , F , TF } + { + \if_int_compare:w + \@@_if_eq:nn { \exp_not:n {#1} } { \exp_not:n {#3} } + #2 \c_zero_int + \prg_return_true: \else: \prg_return_false: \fi: + } +\prg_new_conditional:Npnn \str_compare:eNe #1#2#3 { p , T , F , TF } + { + \if_int_compare:w \@@_if_eq:nn {#1} {#3} #2 \c_zero_int + \prg_return_true: \else: \prg_return_false: \fi: + } +% \end{macrocode} +% \end{macro} +% +% \begin{macro}[pTF, EXP] +% { +% \str_if_eq:nn, \str_if_eq:Vn, \str_if_eq:on, \str_if_eq:nV, +% \str_if_eq:no, \str_if_eq:VV, +% \str_if_eq:ee +% } +% Modern engines provide a direct way of comparing two token lists, +% but returning a number. This set of conditionals therefore makes life +% a bit clearer. The \texttt{nn} and \texttt{ee} versions are created +% directly as this is most efficient. Since \cs{@@_if_eq:nn} will expand to +% |0| as an explicit character with category 12 if the two lists match (and +% either |-1| or |1| if they don't) we can use \cs{if:w} here which is faster +% than using \cs{if_int_compare:w}. +% \begin{macrocode} +\prg_new_conditional:Npnn \str_if_eq:nn #1#2 { p , T , F , TF } + { + \if:w 0 \@@_if_eq:nn { \exp_not:n {#1} } { \exp_not:n {#2} } + \prg_return_true: \else: \prg_return_false: \fi: + } +\prg_generate_conditional_variant:Nnn \str_if_eq:nn + { V , v , o , nV , no , VV , nv } { p , T , F , TF } +\prg_new_conditional:Npnn \str_if_eq:ee #1#2 { p , T , F , TF } + { + \if:w 0 \@@_if_eq:nn {#1} {#2} + \prg_return_true: \else: \prg_return_false: \fi: + } +% \end{macrocode} +% \end{macro} +% +% \begin{macro}[EXP, pTF] +% {\str_if_eq:NN, \str_if_eq:Nc, \str_if_eq:cN, \str_if_eq:cc} +% Note that \cs{str_if_eq:NNTF} is different from +% \cs{tl_if_eq:NNTF} because it needs to ignore category codes. +% \begin{macrocode} +\prg_new_conditional:Npnn \str_if_eq:NN #1#2 { p , TF , T , F } + { + \if:w 0 \@@_if_eq:nn { \tl_to_str:N #1 } { \tl_to_str:N #2 } + \prg_return_true: \else: \prg_return_false: \fi: + } +\prg_generate_conditional_variant:Nnn \str_if_eq:NN + { c , Nc , cc } { T , F , TF , p } +% \end{macrocode} +% \end{macro} +% +% \begin{macro}[TF]{\str_if_in:Nn, \str_if_in:cn, \str_if_in:nn} +% Everything here needs to be detokenized but beyond that it is a +% simple token list test. It would be faster to fine-tune the |T|, +% |F|, |TF| variants by calling the appropriate variant of +% \cs{tl_if_in:nnTF} directly but that takes more code. +% \begin{macrocode} +\prg_new_protected_conditional:Npnn \str_if_in:Nn #1#2 { T , F , TF } + { + \use:e + { \tl_if_in:nnTF { \tl_to_str:N #1 } { \tl_to_str:n {#2} } } + { \prg_return_true: } { \prg_return_false: } + } +\prg_generate_conditional_variant:Nnn \str_if_in:Nn + { c } { T , F , TF } +\prg_new_protected_conditional:Npnn \str_if_in:nn #1#2 { T , F , TF } + { + \use:e + { \tl_if_in:nnTF { \tl_to_str:n {#1} } { \tl_to_str:n {#2} } } + { \prg_return_true: } { \prg_return_false: } + } +% \end{macrocode} +% \end{macro} +% +% \begin{macro}[EXP, noTF] +% { +% \str_case:nn, \str_case:Vn, \str_case:Nn, \str_case:on, \str_case:en, \str_case:nV, \str_case:nv, +% \str_case_e:nn, \str_case_e:en +% } +% \begin{macro}[EXP]{\@@_case:nnTF, \@@_case_e:nnTF} +% \begin{macro}[EXP] +% {\@@_case:nw, \@@_case_e:nw, \@@_case_end:nw} +% The aim here is to allow the case statement to be evaluated +% using a known number of expansion steps (two), and without +% needing to use an explicit \enquote{end of recursion} marker. +% That is achieved by using the test input as the final case, +% as this is always true. The trick is then to tidy up +% the output such that the appropriate case code plus either +% the \texttt{true} or \texttt{false} branch code is inserted. +% \begin{macrocode} +\cs_new:Npn \str_case:nn #1#2 + { + \exp:w + \@@_case:nnTF {#1} {#2} { } { } + } +\cs_new:Npn \str_case:nnT #1#2#3 + { + \exp:w + \@@_case:nnTF {#1} {#2} {#3} { } + } +\cs_new:Npn \str_case:nnF #1#2 + { + \exp:w + \@@_case:nnTF {#1} {#2} { } + } +\cs_new:Npn \str_case:nnTF #1#2 + { + \exp:w + \@@_case:nnTF {#1} {#2} + } +\cs_new:Npn \@@_case:nnTF #1#2#3#4 + { \@@_case:nw {#1} #2 {#1} { } \s_@@_mark {#3} \s_@@_mark {#4} \s_@@_stop } +\cs_generate_variant:Nn \str_case:nn { V , o , e , nV , nv } +\prg_generate_conditional_variant:Nnn \str_case:nn + { V , o , e , nV , nv } { T , F , TF } +\cs_new_eq:NN \str_case:Nn \str_case:Vn +\cs_new_eq:NN \str_case:NnT \str_case:VnT +\cs_new_eq:NN \str_case:NnF \str_case:VnF +\cs_new_eq:NN \str_case:NnTF \str_case:VnTF +\cs_new:Npn \@@_case:nw #1#2#3 + { + \str_if_eq:nnTF {#1} {#2} + { \@@_case_end:nw {#3} } + { \@@_case:nw {#1} } + } +\cs_new:Npn \str_case_e:nn #1#2 + { + \exp:w + \@@_case_e:nnTF {#1} {#2} { } { } + } +\cs_new:Npn \str_case_e:nnT #1#2#3 + { + \exp:w + \@@_case_e:nnTF {#1} {#2} {#3} { } + } +\cs_new:Npn \str_case_e:nnF #1#2 + { + \exp:w + \@@_case_e:nnTF {#1} {#2} { } + } +\cs_new:Npn \str_case_e:nnTF #1#2 + { + \exp:w + \@@_case_e:nnTF {#1} {#2} + } +\cs_new:Npn \@@_case_e:nnTF #1#2#3#4 + { \@@_case_e:nw {#1} #2 {#1} { } \s_@@_mark {#3} \s_@@_mark {#4} \s_@@_stop } +\cs_generate_variant:Nn \str_case_e:nn { e } +\prg_generate_conditional_variant:Nnn \str_case_e:nn { e } { T , F , TF } +\cs_new:Npn \@@_case_e:nw #1#2#3 + { + \str_if_eq:eeTF {#1} {#2} + { \@@_case_end:nw {#3} } + { \@@_case_e:nw {#1} } + } +% \end{macrocode} +% To tidy up the recursion, there are two outcomes. If there was a hit to +% one of the cases searched for, then |#1| is the code to insert, +% |#2| is the \emph{next} case to check on and |#3| is all of +% the rest of the cases code. That means that |#4| is the \texttt{true} +% branch code, and |#5| tidies up the spare \cs{s_@@_mark} and the +% \texttt{false} branch. On the other hand, if none of the cases matched +% then we arrive here using the \enquote{termination} case of comparing +% the search with itself. That means that |#1| is empty, |#2| is +% the first \cs{s_@@_mark} and so |#4| is the \texttt{false} code (the +% \texttt{true} code is mopped up by |#3|). +% \begin{macrocode} +\cs_new:Npn \@@_case_end:nw #1#2#3 \s_@@_mark #4#5 \s_@@_stop + { \exp_end: #1 #4 } +% \end{macrocode} +% \end{macro} +% \end{macro} +% \end{macro} +% +% \subsection{Mapping over strings} +% +% \begin{macro}[rEXP]{\str_map_function:NN, \str_map_function:cN} +% \begin{macro}[rEXP]{\str_map_function:nN} +% \begin{macro}{\str_map_inline:Nn, \str_map_inline:cn} +% \begin{macro}{\str_map_inline:nn} +% \begin{macro}{\str_map_variable:NNn, \str_map_variable:cNn} +% \begin{macro}{\str_map_variable:nNn} +% \begin{macro}{\str_map_break:} +% \begin{macro}{\str_map_break:n} +% \begin{macro}[rEXP]{\@@_map_function:w, \@@_map_function:nn} +% \begin{macro}{\@@_map_inline:NN, \@@_map_variable:NnN} +% The inline and variable mappings are similar to the usual token list +% mappings but start out by turning the argument to an ``other +% string''. Doing the same for the expandable function mapping would +% require \cs{__kernel_str_to_other:n}, quadratic in the string length. To deal +% with spaces in that case, \cs{@@_map_function:w} replaces the +% following space by a braced space and a further call to itself. +% These are received by \cs{@@_map_function:nn}, which passes +% the space to |#1| and calls \cs{@@_map_function:w} to deal with the +% next space. The space before the braced space allows to optimize +% the \cs{q_@@_recursion_tail} test. Of course we need to include a +% trailing space (the question mark is needed to avoid losing the +% space when \TeX{} tokenizes the line). +% At the cost of about three more auxiliaries this code could get a $9$ +% times speed up by testing only every $9$-th character for whether it +% is \cs{q_@@_recursion_tail} (also by converting $9$ spaces at a time in +% the \cs{str_map_function:nN} case). +% +% For the \texttt{map_variable} functions we use a string assignment +% to store each character because spaces are made catcode~$12$ before +% the loop. +% \begin{macrocode} +\cs_new:Npn \str_map_function:nN #1#2 + { + \exp_after:wN \@@_map_function:w + \exp_after:wN \@@_map_function:nn \exp_after:wN #2 + \__kernel_tl_to_str:w {#1} + \q_@@_recursion_tail ? ~ + \prg_break_point:Nn \str_map_break: { } + } +\cs_new:Npn \str_map_function:NN + { \exp_args:No \str_map_function:nN } +\cs_new:Npn \@@_map_function:w #1 ~ + { #1 { ~ { ~ } \@@_map_function:w } } +\cs_new:Npn \@@_map_function:nn #1#2 + { + \if_meaning:w \q_@@_recursion_tail #2 + \exp_after:wN \str_map_break: + \fi: + #1 #2 \@@_map_function:nn {#1} + } +\cs_generate_variant:Nn \str_map_function:NN { c } +\cs_new_protected:Npn \str_map_inline:nn #1#2 + { + \int_gincr:N \g__kernel_prg_map_int + \cs_gset_protected:cpn + { @@_map_ \int_use:N \g__kernel_prg_map_int :w } ##1 {#2} + \use:e + { + \exp_not:N \@@_map_inline:NN + \exp_not:c { @@_map_ \int_use:N \g__kernel_prg_map_int :w } + \__kernel_str_to_other_fast:n {#1} + } + \q_@@_recursion_tail + \prg_break_point:Nn \str_map_break: + { \int_gdecr:N \g__kernel_prg_map_int } + } +\cs_new_protected:Npn \str_map_inline:Nn + { \exp_args:No \str_map_inline:nn } +\cs_generate_variant:Nn \str_map_inline:Nn { c } +\cs_new:Npn \@@_map_inline:NN #1#2 + { + \@@_if_recursion_tail_break:NN #2 \str_map_break: + \exp_args:No #1 { \token_to_str:N #2 } + \@@_map_inline:NN #1 + } +\cs_new_protected:Npn \str_map_variable:nNn #1#2#3 + { + \use:e + { + \exp_not:n { \@@_map_variable:NnN #2 {#3} } + \__kernel_str_to_other_fast:n {#1} + } + \q_@@_recursion_tail + \prg_break_point:Nn \str_map_break: { } + } +\cs_new_protected:Npn \str_map_variable:NNn + { \exp_args:No \str_map_variable:nNn } +\cs_new_protected:Npn \@@_map_variable:NnN #1#2#3 + { + \@@_if_recursion_tail_break:NN #3 \str_map_break: + \str_set:Nn #1 {#3} + \use:n {#2} + \@@_map_variable:NnN #1 {#2} + } +\cs_generate_variant:Nn \str_map_variable:NNn { c } +\cs_new:Npn \str_map_break: + { \prg_map_break:Nn \str_map_break: { } } +\cs_new:Npn \str_map_break:n + { \prg_map_break:Nn \str_map_break: } +% \end{macrocode} +% \end{macro} +% \end{macro} +% \end{macro} +% \end{macro} +% \end{macro} +% \end{macro} +% \end{macro} +% \end{macro} +% \end{macro} +% \end{macro} +% +% \begin{macro}[rEXP]{\str_map_tokens:Nn, \str_map_tokens:cn} +% \begin{macro}[rEXP]{\str_map_tokens:nn} +% Uses an auxiliary of \cs{str_map_function:NN}. +% \begin{macrocode} +\cs_new:Npn \str_map_tokens:nn #1#2 + { + \exp_args:Nno \use:nn + { \@@_map_function:w \@@_map_function:nn {#2} } + { \__kernel_tl_to_str:w {#1} } + \q_@@_recursion_tail ? ~ + \prg_break_point:Nn \str_map_break: { } + } +\cs_new:Npn \str_map_tokens:Nn { \exp_args:No \str_map_tokens:nn } +\cs_generate_variant:Nn \str_map_tokens:Nn { c } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \subsection{Accessing specific characters in a string} +% +% \begin{macro}[EXP]{\__kernel_str_to_other:n} +% \begin{macro}[EXP]{\@@_to_other_loop:w, \@@_to_other_end:w} +% First apply \cs{tl_to_str:n}, then replace all spaces by +% \enquote{other} spaces, $8$ at a time, storing the converted part of +% the string between the \cs{s_@@_mark} and \cs{s_@@_stop} markers. The end +% is detected when \cs{@@_to_other_loop:w} finds one of the trailing +% |A|, distinguished from any contents of the initial token list by +% their category. Then \cs{@@_to_other_end:w} is called, and finds +% the result between \cs{s_@@_mark} and the first |A| (well, there is +% also the need to remove a space). +% \begin{macrocode} +\cs_new:Npn \__kernel_str_to_other:n #1 + { + \exp_after:wN \@@_to_other_loop:w + \tl_to_str:n {#1} ~ A ~ A ~ A ~ A ~ A ~ A ~ A ~ A ~ \s_@@_mark \s_@@_stop + } +\group_begin: +\tex_lccode:D `\* = `\ % +\tex_lccode:D `\A = `\A % +\tex_lowercase:D + { + \group_end: + \cs_new:Npn \@@_to_other_loop:w + #1 ~ #2 ~ #3 ~ #4 ~ #5 ~ #6 ~ #7 ~ #8 ~ #9 \s_@@_stop + { + \if_meaning:w A #8 + \@@_to_other_end:w + \fi: + \@@_to_other_loop:w + #9 #1 * #2 * #3 * #4 * #5 * #6 * #7 * #8 * \s_@@_stop + } + \cs_new:Npn \@@_to_other_end:w \fi: #1 \s_@@_mark #2 * A #3 \s_@@_stop + { \fi: #2 } + } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \begin{macro}[rEXP]{\__kernel_str_to_other_fast:n} +% \begin{macro}[rEXP]{\__kernel_str_to_other_fast_loop:w, \@@_to_other_fast_end:w} +% The difference with \cs{__kernel_str_to_other:n} is that the converted part is +% left in the input stream, making these commands only +% restricted-expandable. +% \begin{macrocode} +\cs_new:Npn \__kernel_str_to_other_fast:n #1 + { + \exp_after:wN \@@_to_other_fast_loop:w \tl_to_str:n {#1} ~ + A ~ A ~ A ~ A ~ A ~ A ~ A ~ A ~ A ~ \s_@@_stop + } +\group_begin: +\tex_lccode:D `\* = `\ % +\tex_lccode:D `\A = `\A % +\tex_lowercase:D + { + \group_end: + \cs_new:Npn \@@_to_other_fast_loop:w + #1 ~ #2 ~ #3 ~ #4 ~ #5 ~ #6 ~ #7 ~ #8 ~ #9 ~ + { + \if_meaning:w A #9 + \@@_to_other_fast_end:w + \fi: + #1 * #2 * #3 * #4 * #5 * #6 * #7 * #8 * #9 + \@@_to_other_fast_loop:w * + } + \cs_new:Npn \@@_to_other_fast_end:w #1 * A #2 \s_@@_stop {#1} + } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \begin{macro}[EXP] +% {\str_item:Nn, \str_item:cn, \str_item:nn, \str_item_ignore_spaces:nn} +% \begin{macro}[EXP]{\@@_item:nn, \@@_item:w} +% The \cs{str_item:nn} hands its argument with spaces escaped to +% \cs{@@_item:nn}, and makes sure to turn the result back into +% a proper string (with category code~$10$ spaces) eventually. The +% \cs{str_item_ignore_spaces:nn} function does not escape spaces, +% which are thus ignored by \cs{@@_item:nn} since +% everything else is done with undelimited arguments. +% Evaluate the \meta{index} argument~|#2| and count characters in +% the string, passing those two numbers to \cs{@@_item:w} for +% further analysis. If the \meta{index} is negative, shift it by +% the \meta{count} to know the how many character to discard, and if +% that is still negative give an empty result. If the \meta{index} +% is larger than the \meta{count}, give an empty result, and +% otherwise discard $\meta{index}-1$ characters before returning the +% following one. The shift by $-1$ is obtained by inserting an empty +% brace group before the string in that case: that brace group also +% covers the case where the \meta{index} is zero. +% \begin{macrocode} +\cs_new:Npn \str_item:Nn { \exp_args:No \str_item:nn } +\cs_generate_variant:Nn \str_item:Nn { c } +\cs_new:Npn \str_item:nn #1#2 + { + \exp_args:Nf \tl_to_str:n + { + \exp_args:Nf \@@_item:nn + { \__kernel_str_to_other:n {#1} } {#2} + } + } +\cs_new:Npn \str_item_ignore_spaces:nn #1 + { \exp_args:No \@@_item:nn { \tl_to_str:n {#1} } } +\cs_new:Npn \@@_item:nn #1#2 + { + \exp_after:wN \@@_item:w + \int_value:w \int_eval:n {#2} \exp_after:wN ; + \int_value:w \@@_count:n {#1} ; + #1 \s_@@_stop + } +\cs_new:Npn \@@_item:w #1; #2; + { + \int_compare:nNnTF {#1} < 0 + { + \int_compare:nNnTF {#1} < {-#2} + { \@@_use_none_delimit_by_s_stop:w } + { + \exp_after:wN \@@_use_i_delimit_by_s_stop:nw + \exp:w \exp_after:wN \@@_skip_exp_end:w + \int_value:w \int_eval:n { #1 + #2 } ; + } + } + { + \int_compare:nNnTF {#1} > {#2} + { \@@_use_none_delimit_by_s_stop:w } + { + \exp_after:wN \@@_use_i_delimit_by_s_stop:nw + \exp:w \@@_skip_exp_end:w #1 ; { } + } + } + } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \begin{macro}[EXP]{\@@_skip_exp_end:w} +% \begin{macro}[EXP] +% {\@@_skip_loop:wNNNNNNNN, \@@_skip_end:w, \@@_skip_end:NNNNNNNN} +% Removes |max(#1,0)| characters from the input stream, and then +% leaves \cs{exp_end:}. This should be expanded using +% \cs{exp:w}. We remove characters $8$ at a time until +% there are at most $8$ to remove. Then we do a dirty trick: the +% \cs{if_case:w} construction leaves between $0$ and $8$ times the +% \cs{or:} control sequence, and those \cs{or:} become arguments of +% \cs{@@_skip_end:NNNNNNNN}. If the number of characters to remove +% is $6$, say, then there are two \cs{or:} left, and the $8$ arguments +% of \cs{@@_skip_end:NNNNNNNN} are the two \cs{or:}, and $6$ +% characters from the input stream, exactly what we wanted to +% remove. Then close the \cs{if_case:w} conditional with \cs{fi:}, and +% stop the initial expansion with \cs{exp_end:} (see places where +% \cs{@@_skip_exp_end:w} is called). +% \begin{macrocode} +\cs_new:Npn \@@_skip_exp_end:w #1; + { + \if_int_compare:w #1 > 8 \exp_stop_f: + \exp_after:wN \@@_skip_loop:wNNNNNNNN + \else: + \exp_after:wN \@@_skip_end:w + \int_value:w \int_eval:w + \fi: + #1 ; + } +\cs_new:Npn \@@_skip_loop:wNNNNNNNN #1; #2#3#4#5#6#7#8#9 + { + \exp_after:wN \@@_skip_exp_end:w + \int_value:w \int_eval:n { #1 - 8 } ; + } +\cs_new:Npn \@@_skip_end:w #1 ; + { + \exp_after:wN \@@_skip_end:NNNNNNNN + \if_case:w #1 \exp_stop_f: \or: \or: \or: \or: \or: \or: \or: \or: + } +\cs_new:Npn \@@_skip_end:NNNNNNNN #1#2#3#4#5#6#7#8 { \fi: \exp_end: } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \begin{macro}[EXP] +% {\str_range:Nnn, \str_range:nnn, \str_range_ignore_spaces:nnn} +% \begin{macro}[EXP]{\@@_range:nnn} +% \begin{macro}[EXP]{\@@_range:w, \@@_range:nnw} +% Sanitize the string. Then evaluate the arguments. At this stage we +% also decrement the \meta{start index}, since our goal is to know how +% many characters should be removed. Then limit the range to be +% non-negative and at most the length of the string (this avoids +% needing to check for the end of the string when grabbing +% characters), shifting negative numbers by the appropriate amount. +% Afterwards, skip characters, then keep some more, and finally drop +% the end of the string. +% \begin{macrocode} +\cs_new:Npn \str_range:Nnn { \exp_args:No \str_range:nnn } +\cs_generate_variant:Nn \str_range:Nnn { c } +\cs_new:Npn \str_range:nnn #1#2#3 + { + \exp_args:Nf \tl_to_str:n + { + \exp_args:Nf \@@_range:nnn + { \__kernel_str_to_other:n {#1} } {#2} {#3} + } + } +\cs_new:Npn \str_range_ignore_spaces:nnn #1 + { \exp_args:No \@@_range:nnn { \tl_to_str:n {#1} } } +\cs_new:Npn \@@_range:nnn #1#2#3 + { + \exp_after:wN \@@_range:w + \int_value:w \@@_count:n {#1} \exp_after:wN ; + \int_value:w \int_eval:n { (#2) - 1 } \exp_after:wN ; + \int_value:w \int_eval:n {#3} ; + #1 \s_@@_stop + } +\cs_new:Npn \@@_range:w #1; #2; #3; + { + \exp_args:Nf \@@_range:nnw + { \@@_range_normalize:nn {#2} {#1} } + { \@@_range_normalize:nn {#3} {#1} } + } +\cs_new:Npn \@@_range:nnw #1#2 + { + \exp_after:wN \@@_collect_delimit_by_q_stop:w + \int_value:w \int_eval:n { #2 - #1 } \exp_after:wN ; + \exp:w \@@_skip_exp_end:w #1 ; + } +% \end{macrocode} +% \end{macro} +% \end{macro} +% \end{macro} +% \begin{macro}[EXP]{\@@_range_normalize:nn} +% This function converts an \meta{index} argument into an explicit +% position in the string (a result of $0$ denoting \enquote{out of +% bounds}). Expects two explicit integer arguments: the +% \meta{index} |#1| and the string count~|#2|. If |#1| is negative, +% replace it by $|#1| + |#2| + 1$, then limit to the range $[0, +% |#2|]$. +% \begin{macrocode} +\cs_new:Npn \@@_range_normalize:nn #1#2 + { + \int_eval:n + { + \if_int_compare:w #1 < \c_zero_int + \if_int_compare:w #1 < -#2 \exp_stop_f: + 0 + \else: + #1 + #2 + 1 + \fi: + \else: + \if_int_compare:w #1 < #2 \exp_stop_f: + #1 + \else: + #2 + \fi: + \fi: + } + } +% \end{macrocode} +% \end{macro} +% \begin{macro}[EXP]{\@@_collect_delimit_by_q_stop:w} +% \begin{macro}[EXP] +% { +% \@@_collect_loop:wn, \@@_collect_loop:wnNNNNNNN, +% \@@_collect_end:wn, \@@_collect_end:nnnnnnnnw +% } +% Collects |max(#1,0)| characters, and removes everything else until +% \cs{s_@@_stop}. This is somewhat similar to \cs{@@_skip_exp_end:w}, but +% accepts integer expression arguments. This time we can only grab +% $7$ characters at a time. At the end, we use an \cs{if_case:w} +% trick again, so that the $8$ first arguments of +% \cs{@@_collect_end:nnnnnnnnw} are some \cs{or:}, followed by an +% \cs{fi:}, followed by |#1| characters from the input stream. Simply +% leaving this in the input stream closes the conditional properly +% and the \cs{or:} disappear. +% \begin{macrocode} +\cs_new:Npn \@@_collect_delimit_by_q_stop:w #1; + { \@@_collect_loop:wn #1 ; { } } +\cs_new:Npn \@@_collect_loop:wn #1 ; + { + \if_int_compare:w #1 > 7 \exp_stop_f: + \exp_after:wN \@@_collect_loop:wnNNNNNNN + \else: + \exp_after:wN \@@_collect_end:wn + \fi: + #1 ; + } +\cs_new:Npn \@@_collect_loop:wnNNNNNNN #1; #2 #3#4#5#6#7#8#9 + { + \exp_after:wN \@@_collect_loop:wn + \int_value:w \int_eval:n { #1 - 7 } ; + { #2 #3#4#5#6#7#8#9 } + } +\cs_new:Npn \@@_collect_end:wn #1 ; + { + \exp_after:wN \@@_collect_end:nnnnnnnnw + \if_case:w \if_int_compare:w #1 > \c_zero_int + #1 \else: 0 \fi: \exp_stop_f: + \or: \or: \or: \or: \or: \or: \fi: + } +\cs_new:Npn \@@_collect_end:nnnnnnnnw #1#2#3#4#5#6#7#8 #9 \s_@@_stop + { #1#2#3#4#5#6#7#8 } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \subsection{Counting characters} +% +% \begin{macro}[EXP] +% {\str_count_spaces:N, \str_count_spaces:c, \str_count_spaces:n} +% \begin{macro}[EXP]{\@@_count_spaces_loop:w} +% To speed up this function, we grab and discard $9$ space-delimited +% arguments in each iteration of the loop. The loop stops when the +% last argument is one of the trailing |X|\meta{number}, and that +% \meta{number} is added to the sum of $9$ that precedes, to adjust +% the result. +% \begin{macrocode} +\cs_new:Npn \str_count_spaces:N + { \exp_args:No \str_count_spaces:n } +\cs_generate_variant:Nn \str_count_spaces:N { c } +\cs_new:Npn \str_count_spaces:n #1 + { + \int_eval:n + { + \exp_after:wN \@@_count_spaces_loop:w + \tl_to_str:n {#1} ~ + X 7 ~ X 6 ~ X 5 ~ X 4 ~ X 3 ~ X 2 ~ X 1 ~ X 0 ~ X -1 ~ + \s_@@_stop + } + } +\cs_new:Npn \@@_count_spaces_loop:w #1~#2~#3~#4~#5~#6~#7~#8~#9~ + { + \if_meaning:w X #9 + \@@_use_i_delimit_by_s_stop:nw + \fi: + 9 + \@@_count_spaces_loop:w + } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \begin{macro}[EXP] +% {\str_count:N, \str_count:c, \str_count:n, \str_count_ignore_spaces:n} +% \begin{macro}[EXP]{\@@_count:n} +% \begin{macro}[EXP]{\@@_count_aux:n, \@@_count_loop:NNNNNNNNN} +% To count characters in a string we could first escape all spaces +% using \cs{__kernel_str_to_other:n}, then pass the result to \cs{tl_count:n}. +% However, the escaping step would be quadratic in the number of +% characters in the string, and we can do better. Namely, sum the +% number of spaces (\cs{str_count_spaces:n}) and the result of +% \cs{tl_count:n}, which ignores spaces. Since strings tend to be +% longer than token lists, we use specialized functions to count +% characters ignoring spaces. Namely, loop, grabbing $9$ non-space +% characters at each step, and end as soon as we reach one of the $9$ +% trailing items. The internal function \cs{@@_count:n}, used in +% \cs{str_item:nn} and \cs{str_range:nnn}, is similar to +% \cs{str_count_ignore_spaces:n} but expects its argument to already +% be a string or a string with spaces escaped. +% \begin{macrocode} +\cs_new:Npn \str_count:N { \exp_args:No \str_count:n } +\cs_generate_variant:Nn \str_count:N { c } +\cs_new:Npn \str_count:n #1 + { + \@@_count_aux:n + { + \str_count_spaces:n {#1} + + \exp_after:wN \@@_count_loop:NNNNNNNNN \tl_to_str:n {#1} + } + } +\cs_new:Npn \@@_count:n #1 + { + \@@_count_aux:n + { \@@_count_loop:NNNNNNNNN #1 } + } +\cs_new:Npn \str_count_ignore_spaces:n #1 + { + \@@_count_aux:n + { \exp_after:wN \@@_count_loop:NNNNNNNNN \tl_to_str:n {#1} } + } +\cs_new:Npn \@@_count_aux:n #1 + { + \int_eval:n + { + #1 + { X 8 } { X 7 } { X 6 } + { X 5 } { X 4 } { X 3 } + { X 2 } { X 1 } { X 0 } + \s_@@_stop + } + } +\cs_new:Npn \@@_count_loop:NNNNNNNNN #1#2#3#4#5#6#7#8#9 + { + \if_meaning:w X #9 + \exp_after:wN \@@_use_none_delimit_by_s_stop:w + \fi: + 9 + \@@_count_loop:NNNNNNNNN + } +% \end{macrocode} +% \end{macro} +% \end{macro} +% \end{macro} +% +% \subsection{The first character in a string} +% +% \begin{macro}[EXP] +% {\str_head:N, \str_head:c, \str_head:n, \str_head_ignore_spaces:n} +% \begin{macro}[EXP]{\@@_head:w} +% The \texttt{_ignore_spaces} variant applies \cs{tl_to_str:n} then +% grabs the first item, thus skipping spaces. +% As usual, \cs{str_head:N} expands its argument and +% hands it to \cs{str_head:n}. To circumvent the fact that \TeX{} +% skips spaces when grabbing undelimited macro parameters, +% \cs{@@_head:w} takes an argument delimited by a space. If |#1| +% starts with a non-space character, \cs{@@_use_i_delimit_by_s_stop:nw} +% leaves that in the input stream. On the other hand, if |#1| starts +% with a space, the \cs{@@_head:w} takes an empty argument, and the +% single (initially braced) space in the definition of \cs{@@_head:w} +% makes its way to the output. Finally, for an empty argument, the +% (braced) empty brace group in the definition of \cs{str_head:n} +% gives an empty result after passing through +% \cs{@@_use_i_delimit_by_s_stop:nw}. +% \begin{macrocode} +\cs_new:Npn \str_head:N { \exp_args:No \str_head:n } +\cs_generate_variant:Nn \str_head:N { c } +\cs_new:Npn \str_head:n #1 + { + \exp_after:wN \@@_head:w + \tl_to_str:n {#1} + { { } } ~ \s_@@_stop + } +\cs_new:Npn \@@_head:w #1 ~ % + { \@@_use_i_delimit_by_s_stop:nw #1 { ~ } } +\cs_new:Npn \str_head_ignore_spaces:n #1 + { + \exp_after:wN \@@_use_i_delimit_by_s_stop:nw + \tl_to_str:n {#1} { } \s_@@_stop + } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \begin{macro}[EXP] +% {\str_tail:N, \str_tail:c, \str_tail:n, \str_tail_ignore_spaces:n} +% \begin{macro}[EXP]{\@@_tail_auxi:w, \@@_tail_auxii:w} +% Getting the tail is a little bit more convoluted than the head of a +% string. We hit the front of the string with \cs{reverse_if:N} +% \cs{if_charcode:w} \cs{scan_stop:}. This removes the first +% character, and necessarily makes the test true, since the character +% cannot match \cs{scan_stop:}. The auxiliary function then inserts +% the required \cs{fi:} to close the conditional, and leaves the tail +% of the string in the input stream. The details are such that an +% empty string has an empty tail (this requires in particular that the +% end-marker |X| be unexpandable and not a control sequence). The +% \texttt{_ignore_spaces} is rather simpler: after converting the +% input to a string, \cs{@@_tail_auxii:w} removes one undelimited +% argument and leaves everything else until an end-marker \cs{s_@@_mark}. +% One can check that an empty (or blank) string yields an empty +% tail. +% \begin{macrocode} +\cs_new:Npn \str_tail:N { \exp_args:No \str_tail:n } +\cs_generate_variant:Nn \str_tail:N { c } +\cs_new:Npn \str_tail:n #1 + { + \exp_after:wN \@@_tail_auxi:w + \reverse_if:N \if_charcode:w + \scan_stop: \tl_to_str:n {#1} X X \s_@@_stop + } +\cs_new:Npn \@@_tail_auxi:w #1 X #2 \s_@@_stop { \fi: #1 } +\cs_new:Npn \str_tail_ignore_spaces:n #1 + { + \exp_after:wN \@@_tail_auxii:w + \tl_to_str:n {#1} \s_@@_mark \s_@@_mark \s_@@_stop + } +\cs_new:Npn \@@_tail_auxii:w #1 #2 \s_@@_mark #3 \s_@@_stop { #2 } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \subsection{String manipulation} +% +% \begin{macro}[EXP] +% { +% \str_casefold:n, \str_casefold:V, +% \str_lowercase:n, \str_lowercase:f, +% \str_uppercase:n, \str_uppercase:f +% } +% \begin{macro}[EXP]{\@@_change_case:nn} +% \begin{macro}[EXP]{\@@_change_case_aux:nn} +% \begin{macro}[EXP]{\@@_change_case_result:n} +% \begin{macro}[EXP]{\@@_change_case_output:nw, \@@_change_case_output:fw} +% \begin{macro}[EXP]{\@@_change_case_end:nw} +% \begin{macro}[EXP]{\@@_change_case_loop:nw} +% \begin{macro}[EXP]{\@@_change_case_space:n} +% \begin{macro}[EXP] +% {\@@_change_case_char:nN, \@@_change_case_char_auxi:nN, \@@_change_case_char_auxii:nN} +% \begin{macro}[EXP]{\@@_change_case_codepoint:nN} +% \begin{macro}[EXP]{\@@_change_case_codepoint:nNN} +% \begin{macro}[EXP]{\@@_change_case_codepoint:nNNN} +% \begin{macro}[EXP]{\@@_change_case_codepoint:nNNNN} +% \begin{macro}[EXP]{\@@_change_case_char:nnn, \@@_change_case_char_aux:nnn} +% \begin{macro}[EXP]{\@@_change_case_char:nnnnn} +% Case changing for programmatic reasons is done by first detokenizing +% input then doing a simple loop that only has to worry about spaces +% and everything else. The output is detokenized to allow data sharing +% with text-based case changing. Similarly, for $8$-bit engines the +% multi-byte information is shared. +% \begin{macrocode} +\cs_new:Npn \str_casefold:n #1 { \@@_change_case:nn {#1} { casefold } } +\cs_new:Npn \str_lowercase:n #1 { \@@_change_case:nn {#1} { lowercase } } +\cs_new:Npn \str_uppercase:n #1 { \@@_change_case:nn {#1} { uppercase } } +\cs_generate_variant:Nn \str_casefold:n { V } +\cs_generate_variant:Nn \str_lowercase:n { f } +\cs_generate_variant:Nn \str_uppercase:n { f } +\cs_new:Npn \@@_change_case:nn #1 + { + \exp_after:wN \@@_change_case_aux:nn \exp_after:wN + { \tl_to_str:n {#1} } + } +\cs_new:Npn \@@_change_case_aux:nn #1#2 + { + \@@_change_case_loop:nw {#2} #1 \q_@@_recursion_tail \q_@@_recursion_stop + \@@_change_case_result:n { } + } +\cs_new:Npn \@@_change_case_output:nw #1#2 \@@_change_case_result:n #3 + { #2 \@@_change_case_result:n { #3 #1 } } +\cs_generate_variant:Nn \@@_change_case_output:nw { f } +\cs_new:Npn \@@_change_case_end:wn #1 \@@_change_case_result:n #2 + { \tl_to_str:n {#2} } +\cs_new:Npn \@@_change_case_loop:nw #1#2 \q_@@_recursion_stop + { + \tl_if_head_is_space:nTF {#2} + { \@@_change_case_space:n } + { \@@_change_case_char:nN } + {#1} #2 \q_@@_recursion_stop + } +\exp_last_unbraced:NNNNo + \cs_new:Npn \@@_change_case_space:n #1 \c_space_tl + { + \@@_change_case_output:nw { ~ } + \@@_change_case_loop:nw {#1} + } +\cs_new:Npn \@@_change_case_char:nN #1#2 + { + \@@_if_recursion_tail_stop_do:Nn #2 + { \@@_change_case_end:wn } + \@@_change_case_codepoint:nN {#1} #2 + } +\if_int_compare:w 0 + \cs_if_exist:NT \tex_XeTeXversion:D { 1 } + \cs_if_exist:NT \tex_luatexversion:D { 1 } + > 0 \exp_stop_f: + \cs_new:Npn \@@_change_case_codepoint:nN #1#2 + { \@@_change_case_char:fnn { \int_eval:n {`#2} } {#1} {#2} } +\else: + \cs_new:Npe \@@_change_case_codepoint:nN #1#2 + { + \exp_not:N \int_compare:nNnTF {`#2} > { "80 } + { + \cs_if_exist:NTF \tex_pdftexversion:D + { \exp_not:N \@@_change_case_char_auxi:nN } + { + \exp_not:N \int_compare:nNnTF {`#2} > { "FF } + { \exp_not:N \@@_change_case_char_auxii:nN } + { \exp_not:N \@@_change_case_char_auxi:nN } + } + } + { \exp_not:N \@@_change_case_char_auxii:nN } + {#1} #2 + } + \cs_new:Npn \@@_change_case_char_auxi:nN #1#2 + { + \int_compare:nNnTF {`#2} < { "E0 } + { \@@_change_case_codepoint:nNN } + { + \int_compare:nNnTF {`#2} < { "F0 } + { \@@_change_case_codepoint:nNNN } + { \@@_change_case_codepoint:nNNNNN } + } + {#1} #2 + } + \cs_new:Npn \@@_change_case_char_auxii:nN #1#2 + { \@@_change_case_char:fnn { \int_eval:n {`#2} } {#1} {#2} } + \cs_new:Npn \@@_change_case_codepoint:nNN #1#2#3 + { + \@@_change_case_char:fnn + { \int_eval:n { (`#2 - "C0) * "40 + `#3 - "80 } } + {#1} {#2#3} + } + \cs_new:Npn \@@_change_case_codepoint:nNNN #1#2#3#4 + { + \@@_change_case_char:fnn + { + \int_eval:n + { (`#2 - "E0) * "1000 + (`#3 - "80) * "40 + `#4 - "80 } + } + {#1} {#2#3#4} + } + \cs_new:Npn \@@_change_case_codepoint:nNNNN #1#2#3#4#5 + { + \@@_change_case_char:fnn + { + \int_eval:n + { + (`#2 - "F0) * "40000 + + (`#3 - "80) * "1000 + + (`#4 - "80) * "40 + + `#5 - "80 + } + } + {#1} {#2#3#4#5} + } +\fi: +\cs_new:Npn \@@_change_case_char:nnn #1#2#3 + { + \@@_change_case_output:fw + { + \exp_args:Ne \@@_change_case_char_aux:nnn + { \__kernel_codepoint_case:nn {#2} {#1} } {#1} {#3} + } + \@@_change_case_loop:nw {#2} + } +\cs_generate_variant:Nn \@@_change_case_char:nnn { f } +\cs_new:Npn \@@_change_case_char_aux:nnn #1#2#3 + { + \use:e { \@@_change_case_char:nnnnn #1 {#2} {#3} } + } +\cs_new:Npn \@@_change_case_char:nnnnn #1#2#3#4#5 + { + \int_compare:nNnTF {#1} = {#4} + { \tl_to_str:n {#5} } + { + \codepoint_str_generate:n {#1} + \tl_if_blank:nF {#2} + { + \codepoint_str_generate:n {#2} + \tl_if_blank:nF {#3} + { \codepoint_str_generate:n {#3} } + } + } + } +% \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} +% \end{macro} +% \end{macro} +% \end{macro} +% +% \begin{macro}[EXP]{\str_mdfive_hash:n, \str_mdfive_hash:e} +% \begin{macrocode} +\cs_new:Npn \str_mdfive_hash:n #1 { \tex_mdfivesum:D { \tl_to_str:n {#1} } } +\cs_new:Npn \str_mdfive_hash:e #1 { \tex_mdfivesum:D {#1} } +% \end{macrocode} +% \end{macro} +% +% \begin{variable} +% { +% \c_ampersand_str, +% \c_atsign_str, +% \c_backslash_str, +% \c_left_brace_str, +% \c_right_brace_str, +% \c_circumflex_str, +% \c_colon_str, +% \c_dollar_str, +% \c_hash_str, +% \c_percent_str, +% \c_tilde_str, +% \c_underscore_str, +% \c_zero_str +% } +% For all of those strings, use \cs{cs_to_str:N} to get characters with +% the correct category code without worries +% \begin{macrocode} +\str_const:Ne \c_ampersand_str { \cs_to_str:N \& } +\str_const:Ne \c_atsign_str { \cs_to_str:N \@ } +\str_const:Ne \c_backslash_str { \cs_to_str:N \\ } +\str_const:Ne \c_left_brace_str { \cs_to_str:N \{ } +\str_const:Ne \c_right_brace_str { \cs_to_str:N \} } +\str_const:Ne \c_circumflex_str { \cs_to_str:N \^ } +\str_const:Ne \c_colon_str { \cs_to_str:N \: } +\str_const:Ne \c_dollar_str { \cs_to_str:N \$ } +\str_const:Ne \c_hash_str { \cs_to_str:N \# } +\str_const:Ne \c_percent_str { \cs_to_str:N \% } +\str_const:Ne \c_tilde_str { \cs_to_str:N \~ } +\str_const:Ne \c_underscore_str { \cs_to_str:N \_ } +\str_const:Ne \c_zero_str { 0 } +% \end{macrocode} +% \end{variable} +% +% \begin{variable}{\c_empty_str} +% An empty string is simply an empty token list. +% \begin{macrocode} +\cs_new_eq:NN \c_empty_str \c_empty_tl +% \end{macrocode} +% \end{variable} +% +% \begin{variable}{\l_tmpa_str, \l_tmpb_str, \g_tmpa_str, \g_tmpb_str} +% Scratch strings. +% \begin{macrocode} +\str_new:N \l_tmpa_str +\str_new:N \l_tmpb_str +\str_new:N \g_tmpa_str +\str_new:N \g_tmpb_str +% \end{macrocode} +% \end{variable} +% +% \subsection{Viewing strings} +% +% \begin{macro}{\str_show:n, \str_show:N, \str_show:c} +% \begin{macro}{\str_log:n, \str_log:N, \str_log:c} +% Displays a string on the terminal. +% \begin{macrocode} +\cs_new_eq:NN \str_show:n \tl_show:n +\cs_new_protected:Npn \str_show:N #1 + { + \__kernel_chk_tl_type:NnnT #1 { str } { \tl_to_str:N #1 } + { \tl_show:N #1 } + } +\cs_generate_variant:Nn \str_show:N { c } +\cs_new_eq:NN \str_log:n \tl_log:n +\cs_new_protected:Npn \str_log:N #1 + { + \__kernel_chk_tl_type:NnnT #1 { str } { \tl_to_str:N #1 } + { \tl_log:N #1 } + } +\cs_generate_variant:Nn \str_log:N { c } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \begin{macrocode} +%</package> +% \end{macrocode} +% +% \end{implementation} +% +% \PrintIndex |