% \iffalse %% File: l3seq.dtx Copyright (C) 1990-1998 LaTeX3 project % %<*dtx> \ProvidesFile{l3seq.dtx} % %\NeedsTeXFormat{LaTeX2e} %\ProvidesPackage{l3seq} % \ProvidesFile{l3seq.drv} % \fi % \ProvidesFile{l3seq.dtx} [1998/04/20 v1.0d L3 Experimental Token List Pointers] % % \iffalse %<*driver> \documentclass{l3doc} \begin{document} \DocInput{l3seq.dtx} \end{document} % % \fi % % % \GetFileInfo{l3seq.dtx} % \title{The \textsf{l3seq} package\thanks{This file % has version number \fileversion, last % revised \filedate.}\\ % Sequences} % \author{\Team} % \date{\filedate} % \maketitle % % % % \section{Sequence} % % \LaTeX3 implements a data type called `sequences'. These are special % token lists that can be accessed via special function on the `left'. % Appending tokens is possible at both ends. Appended token lists can be % accessed only as a union. The token lists that form the individual % items of a sequence might contain any tokens except two internal % functions that are used to structure sequences (see section internal % functions below). It is also possible to map functions on such % sequences so that they are executed for every item on the sequence. % % All functions that return items from a sequence in some assume % that the is local. See remarks below if you need a global % returned value. % % The defined functions are not orthogonal in the sense that every % possible variation possible is actually available. If you need a new % variant use the expansion functions described in the package % \texttt{l3expan} to build it. % % Adding items to the left of a sequence can currently be done with % either something like "\seq_put_left:Nn" or with a ``stack'' function % like "\seq_push:Nn" which has the same effect. Maybe one should % therefore remove the ``left'' functions totally. % % \subsection{Functions} % % \begin{function}{% % \seq_new:N | % \seq_new:O | % \seq_new:c | % } % \begin{syntax} % "\seq_new:N" % \end{syntax} % Defines to be a variable of type sequences. % \end{function} % % \begin{function}{% % \seq_clear:N | % \seq_clear:c | % \seq_gclear:N | % \seq_gclear:c | % } % \begin{syntax} % "\seq_clear:N" % \end{syntax} % These functions locally or globally clear . % \end{function} % % \begin{function}{% % \seq_put_left:Nn | % \seq_put_left:No | % \seq_put_left:Nx | % \seq_put_left:cn | % \seq_put_right:Nn | % \seq_put_right:No | % \seq_put_right:Nx | % } % \begin{syntax} % "\seq_put_left:Nn" % \end{syntax} % Locally appends as a single item to the left % or right of . might get expanded before % appending. % \end{function} % % \begin{function}{% % \seq_gput_left:Nn | % \seq_gput_right:Nn | % \seq_gput_right:No | % \seq_gput_right:cn | % \seq_gput_right:co | % \seq_gput_right:cc | % } % \begin{syntax} % "\seq_gput_left:Nn" % \end{syntax} % Globally appends as a single item to the left % or right of . % \end{function} % % \begin{function}{% % \seq_get:NN | % \seq_get:cN | % } % \begin{syntax} % "\seq_get:NN" % \end{syntax} % Functions that locally assign the left-most item of to the % token list pointer . Item is not removed from ! If you % need a global return value you need to code something like this: % \begin{quote} % "\seq_get:NN" "\l_tmpa_tlp" \\ % "\tlp_gset_eq:NN" "\l_tmpa_tlp" % \end{quote} % But if this kind of construction is used often enough a separate % function should be provided. % \end{function} % % \begin{function}{% % \seq_gconcat:NNN | % \seq_gconcat:ccc | % } % \begin{syntax} % "\seq_gconcat:NNN" % \end{syntax} % Function that conatenates and and globally assigns the % result to . % \end{function} % % \begin{function}{\seq_map:NN} % \begin{syntax} % "\seq_map:NN" % \end{syntax} % This function applies (which must be a function with one % argument) to every item of . is not executed % within a sub-group so that side effects can be achieved locally. The % operation is not expandable which means that it can't be used within % write operations etc. % % In the current implementation the next functions are more efficient and % should be preferred. % \end{function} % % \begin{function}{\seq_map_inline:Nn | % \seq_map_inline:cn % } % \begin{syntax} % "\seq_map_inline:Nn" "{" "}" % \end{syntax} % Applies (which should be the direct coding for a % function with one argument (i.e.\ use "##1" as the place holder for % this argument)) to every item of . is not % executed within a sub-group so that side effects can be achieved locally. % The operation is not expandable which means that it can't be used % within write operations etc. % \end{function} % % \subsection{Predicates and conditionals} % % \begin{function}{\seq_empty_p:N} % \begin{syntax} % "\seq_empty_p:N" % \end{syntax} % This predicate returns `true' if is `empty' i.e., doesn't % contain any tokens. % \end{function} % % \begin{function}{% % \seq_empty:NTF | % \seq_empty:cTF | % \seq_empty:NF | % \seq_empty:cF | % } % \begin{syntax} % "\seq_empty:NTF" "{" "}{" "}" % \end{syntax} % Set of conditionals that test whether or not a particular % is empty and if so executes either or . % \end{function} % % \begin{function}{% % \seq_if_in:NnTF | % \seq_if_in:cnTF | % \seq_if_in:coTF | % } % \begin{syntax} % "\seq_if_in:NnTF" "{" "}{" "}{" "}" % \end{syntax} % Function that tests if is in . Depending on the result % either or is executed. % \end{function} % % \subsection{Internal functions} % % \begin{function}{\seq_empty_err:N} % \begin{syntax} % "\seq_empty_err:N" % \end{syntax} % Signals an \LaTeX3 error if is empty. % \end{function} % % \begin{function}{\seq_pop_aux:nnNN} % \begin{syntax} % "\seq_pop_aux:nnNN" % \end{syntax} % Function that assigns the left-most item of to using % and assigns the tail to using . This % function could be used to implement a global return function. % \end{function} % % \begin{function}{% % \seq_get_aux:w | % \seq_pop_aux:w | % \seq_put_aux:Nnn | % \seq_put_aux:w | % } % Functions used to implement put and get operations. They are not for % meant for direct use. % \end{function} % % \begin{function}{% % \seq_elt:w | % \seq_elt_end: } % Functions (usually used as constants) that separates items within a % sequence. They might get special meaning during mapping operations and % are not supposed to show up as tokens within an item appended to a % sequence. % \end{function} % % % \section {Implementation} % % We start by ensuring that the required packages are loaded. % \begin{macrocode} %\RequirePackage{l3toks} %\RequirePackage{l3quark} %\RequirePackage{l3chk} %\RequirePackage{l3expan} %<*package> % \end{macrocode} % % A sequence is a control sequence whose top-level expansion is of the % form `|\seq_elt:w| \m{text$\sb1$} |\seq_elt_end:| \ldots{} % |\seq_elt:w| \zv{text$\sb{n}$} \ldots'. We use explicit delimiters % instead of braces around \m{text} to allow efficient searching for % an item in the sequence. % % \begin{macro}{\seq_elt:w} % \begin{macro}{\seq_elt_end:} % We allocate the delimiters and make them noops as default. % \begin{macrocode} \let_new:NN \seq_elt:w \use_noop: \let_new:NN \seq_elt_end: \use_noop: % \end{macrocode} % \end{macro} % \end{macro} % % % \begin{macro}{\seq_new:N} % \begin{macro}{\seq_new:O} % \begin{macro}{\seq_new:c} % Sequences are implemented using token lists. % \begin{macrocode} \def_new:Npn \seq_new:N #1{\tlp_new:Nn #1{}} \def_new:Npn \seq_new:c {\exp_args:Nc \seq_new:N} \def_new:Npn \seq_new:O {\exp_args:No \seq_new:N} % \end{macrocode} % \end{macro} % \end{macro} % \end{macro} % % \begin{macro}{\seq_clear:N} % \begin{macro}{\seq_clear:c} % \begin{macro}{\seq_gclear:N} % \begin{macro}{\seq_gclear:c} % Clearing a sequence is the same as clearing a token list. % \begin{macrocode} \let_new:NN \seq_clear:N \tlp_clear:N \let_new:NN \seq_clear:c \tlp_clear:c \let_new:NN \seq_gclear:N \tlp_gclear:N \let_new:NN \seq_gclear:c \tlp_gclear:c % \end{macrocode} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % % \begin{macro}{\seq_clear_new:N} % \begin{macro}{\seq_clear_new:c} % \begin{macro}{\seq_gclear_new:N} % \begin{macro}{\seq_gclear_new:c} % Clearing a sequence is the same as clearing a token list. % \begin{macrocode} \let_new:NN \seq_clear_new:N \tlp_clear_new:N \let_new:NN \seq_clear_new:c \tlp_clear_new:c \let_new:NN \seq_gclear_new:N \tlp_gclear_new:N \let_new:NN \seq_gclear_new:c \tlp_gclear_new:c % \end{macrocode} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % % \begin{macro}{\seq_empty_p:N} % A predicate which evaluates to |\c_true| iff the sequence is empty. % \begin{macrocode} \let_new:NN \seq_empty_p:N \tlp_empty_p:N % \end{macrocode} % \end{macro} % % \begin{macro}{\seq_empty:NTF} % \begin{macro}{\seq_empty:cTF} % \begin{macro}{\seq_empty:NF} % \begin{macro}{\seq_empty:cF} % |\seq_empty:NTF|\m{seq}\m{true~case}\m{false~case} will check % whether the \m{seq} is empty and then select one of the other % arguments. |seq_empty:cTF| turns its first argument into a % control sequence to get the name of the sequence. % \begin{macrocode} \def_new:Npn \seq_empty:NTF #1{ \if_meaning:NN#1\c_empty_tlp \exp_after:NN\use_choice_i:nn \else: \exp_after:NN\use_choice_ii:nn \fi:} \def_new:Npn \seq_empty:cTF {\exp_args:Nc\seq_empty:NTF} % \end{macrocode} % A variant of this, is only to do something if the sequence is % {\em not} empty. % \begin{macrocode} \def_new:Npn \seq_empty:NF #1{ \if_meaning:NN#1\c_empty_tlp \exp_after:NN\use_none:n \else: \exp_after:NN\use:n \fi:} \def_new:Npn \seq_empty:cF {\exp_args:Nc\seq_empty:NF} % \end{macrocode} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % % % \begin{macro}{\seq_empty_err:N} % Signals an error if the sequence is empty. % \begin{macrocode} \def_new:Npn \seq_empty_err:N #1{\if_meaning:NN#1\c_empty_tlp % \end{macrocode} % As I said before, I don't think we need to provide checks for this % kind of error, since it is a severe internal macro package error % that can not be produced by the user directly. Can it? So the % next line of code should be probably removed. % \begin{macrocode} \tlp_clear:N \l_testa_tlp % catch prefixes \err_latex_bug:n{Empty~sequence~`\token_to_string:N#1'}\fi:} % \end{macrocode} % \end{macro} % % \begin{macro}{\seq_get:NN} % \begin{macro}{\seq_get:cN} % |\seq_get:NN |\zz{sequence}\zz{cmd} defines \zz{cmd} to be the % left_most element of \zz{sequence}. % \begin{macrocode} \def_new:Npn \seq_get:NN #1{ \seq_empty_err:N #1 \exp_after:NN\seq_get_aux:w #1\q_stop} \def_new:Npn \seq_get_aux:w \seq_elt:w #1\seq_elt_end: #2\q_stop #3{\tlp_set:Nn #3{#1}} \def_new:Npn \seq_get:cN {\exp_args:Nc \seq_get:NN} % \end{macrocode} % \end{macro} % \end{macro} % % \begin{macro}{\seq_pop_aux:nnNN} % |\seq_pop_aux:nnNN| \zz{def$\sb1$} \zz{def$\sb2$} \zz{sequence} % \zz{cmd} assigns the left_most element of \zz{sequence} to % \zz{cmd} using \zz{def$\sb2$}, and assigns the tail of % \zz{sequence} to \zz{sequence} using \zz{def$\sb1$}. % \begin{macrocode} \def_new:Npn \seq_pop_aux:nnNN #1#2#3{ \seq_empty_err:N #3 \exp_after:NN\seq_pop_aux:w #3\q_stop #1#2#3} \def_new:Npn \seq_pop_aux:w \seq_elt:w #1\seq_elt_end: #2\q_stop #3#4#5#6{#3#5{#2}#4#6{#1}} % \end{macrocode} % \end{macro} % % \begin{macro}{\seq_put_aux:Nnn} % |\seq_put_aux:Nnn| \zz{sequence} \zv{left} \zv{right} adds the % elements specified by \zv{left} to the left of \zz{sequence}, and % those specified by \zv{right} to the right. % \begin{macrocode} \def_new:Npn \seq_put_aux:Nnn #1{ \exp_after:NN\seq_put_aux:w #1\q_stop #1} \def_new:Npn \seq_put_aux:w #1\q_stop #2#3#4{\tlp_set:Nn #2{#3#1#4}} % \end{macrocode} % \end{macro} % % \begin{macro}{\seq_put_left:Nn} % \begin{macro}{\seq_put_left:No} % \begin{macro}{\seq_put_left:Nx} % \begin{macro}{\seq_put_left:cn} % \begin{macro}{\seq_put_right:Nn} % \begin{macro}{\seq_put_right:No} % \begin{macro}{\seq_put_right:Nx} % Here are the usual operations for adding to the left and right. % \begin{macrocode} \def_new:Npn \seq_put_left:Nn #1#2{ % \end{macrocode} % We can't put in a |\use_noop:| instead of |{}| since this argument is % passed literally (and we would end up with many |\use_noop:|s inside % the sequences. % \begin{macrocode} \seq_put_aux:Nnn #1{\seq_elt:w #2\seq_elt_end:}{}} \def_new:Npn \seq_put_left:cn {\exp_args:Nc\seq_put_left:Nn} \def_new:Npn \seq_put_left:No {\exp_args:NNo\seq_put_left:Nn} \def_new:Npn \seq_put_left:Nx {\exp_args:Nnx\seq_put_left:Nn} \def_new:Npn \seq_put_right:Nn #1#2{ \seq_put_aux:Nnn #1{}{\seq_elt:w #2\seq_elt_end:}} \def_new:Npn \seq_put_right:No {\exp_args:Nno\seq_put_right:Nn} \def_new:Npn \seq_put_right:Nx {\exp_args:Nnx\seq_put_right:Nn} % \end{macrocode} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % % \begin{macro}{\seq_gput_left:Nn} % \begin{macro}{\seq_gput_right:Nn} % \begin{macro}{\seq_gput_right:No} % \begin{macro}{\seq_gput_right:cn} % \begin{macro}{\seq_gput_right:co} % \begin{macro}{\seq_gput_right:cc} % An here the global variants. % \begin{macrocode} \def_new:Npn \seq_gput_left:Nn { %<*check> \pref_global_chk: % %<_check> \pref_global:D \seq_put_left:Nn} \def_new:Npn \seq_gput_right:Nn { %<*check> \pref_global_chk: % %<_check> \pref_global:D \seq_put_right:Nn} \def_new:Npn \seq_gput_right:No {\exp_args:NNo \seq_gput_right:Nn} \def_new:Npn \seq_gput_right:cn {\exp_args:Nc \seq_gput_right:Nn} \def_new:Npn \seq_gput_right:co {\exp_args:Nco \seq_gput_right:Nn} \def_new:Npn \seq_gput_right:cc {\exp_args:Ncc \seq_gput_right:Nn} % \end{macrocode} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % % \begin{macro}{\seq_map:NN} % |\seq_map:NN| \zz{sequence} \zz{cmd} applies \zz{cmd} to each % element of \zz{sequence}, from left to right. Since we don't have % braces, this implementation is not very efficient. It might be % better to say that \zz{cmd} must be a function with one argument % that is delimited by |\seq_elt_end:|. % \begin{macrocode} \def_new:Npn \seq_map:NN #1#2{ \def:Npn \seq_elt:w ##1\seq_elt_end: {#2{##1}}#1} % \end{macrocode} % \end{macro} % % \begin{macro}{\seq_map_inline:Nn} % \begin{macro}{\seq_map_inline:cn} % When no braces are used, this version of mapping seems more % natural. % \begin{macrocode} \def_new:Npn \seq_map_inline:Nn #1#2{ \gdef:Npn \seq_elt:w ##1\seq_elt_end: {#2}#1} \def_new:Npn \seq_map_inline:cn{\exp_args:Nc\seq_map_inline:Nn} % \end{macrocode} % \end{macro} % \end{macro} % % \begin{macro}{\seq_gconcat:NNN} % \begin{macro}{\seq_gconcat:ccc} % |\seq_gconcat:NNN| \m{seq~1} \m{seq~2} \m{seq~3} will globally % assign \m{seq~1} the concatenation of \m{seq~2} and \m{seq~3}. % \begin{macrocode} \def_new:Npn \seq_gconcat:NNN #1#2#3{ \l_tmpa_toks \exp_after:NN{#2} \l_tmpb_toks \exp_after:NN{#3} \gdef:Npx #1{\toks_use:N \l_tmpa_toks \toks_use:N \l_tmpb_toks}} \def_new:Npn \seq_gconcat:ccc{\exp_args:Nccc\seq_gconcat:NNN} % \end{macrocode} % \end{macro} % \end{macro} % % \begin{macro}{\seq_if_in:NnTF} % \begin{macro}{\seq_if_in:cnTF} % \begin{macro}{\seq_if_in:coTF} % |\seq_if_in:NnTF| \m{seq}\m{item} \m{true~case} \m{false~case} % will check whether \m{item} is in \m{seq} and then either execute % the \m{true~case} or the \m{false~case}. \m{true~case} and % \m{false~case} may contain incomplete |\if_char_code:w| % statements. % \begin{macrocode} \def_new:Npn \seq_if_in:NnTF #1#2{ \def:Npn\tmp:w ##1\seq_elt:w #2\seq_elt_end: ##2##3\q_stop{ % \end{macrocode} % Note that |##2| contains exactly one token which we can compare % with |\q_no_value|. % \begin{macrocode} \if_meaning:NN\q_no_value##2 \exp_after:NN\use_choice_ii:nn \else: \exp_after:NN\use_choice_i:nn \fi: } \exp_after:NN \tmp:w #1\seq_elt:w #2\seq_elt_end: \q_no_value \q_stop} \def_new:Npn \seq_if_in:coTF {\exp_args:Nco \seq_if_in:NnTF} \def_new:Npn \seq_if_in:cnTF {\exp_args:Nc \seq_if_in:NnTF} % \end{macrocode} % \end{macro} % \end{macro} % \end{macro} % % % % \subsection{Stack operations} % % We build stacks from sequences, but here we put the % specific functions together. % % % \begin{macro}{\seq_push:Nn} % \begin{macro}{\seq_push:No} % \begin{macro}{\seq_push:cn} % \begin{macro}{\seq_pop:NN} % \begin{macro}{\seq_pop:cN} % Since sequences can be used as stacks, we ought to have both % `push' and `pop'. In most cases they are nothing more then new % names for old functions. % \begin{macrocode} \let_new:NN \seq_push:Nn \seq_put_left:Nn \let_new:NN \seq_push:No \seq_put_left:No \let_new:NN \seq_push:cn \seq_put_left:cn \def_new:Npn \seq_pop:NN {\seq_pop_aux:nnNN \tlp_set:Nn \tlp_set:Nn} \def_new:Npn \seq_pop:cN {\exp_args:Nc \seq_pop:NN} % \end{macrocode} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % % % % \begin{macro}{\seq_gpush:Nn} % \begin{macro}{\seq_gpush:No} % \begin{macro}{\seq_gpush:cn} % \begin{macro}{\seq_gpop:NN} % \begin{macro}{\seq_gpop:cN} % I don't agree with Denys that one needs only local stacks, % actually I believe that one will probably need the functions % here more often. In case of |\seq_gpop:NN| the value is % nevertheless returned locally. % \begin{macrocode} \let_new:NN \seq_gpush:Nn \seq_gput_left:Nn \def_new:Npn \seq_gpush:No {\exp_args:NNo \seq_gpush:Nn} \def_new:Npn \seq_gpush:cn {\exp_args:Nc \seq_gpush:Nn} \def_new:Npn \seq_gpop:NN {\seq_pop_aux:nnNN \tlp_gset:Nn \tlp_set:Nn} \def_new:Npn \seq_gpop:cN {\exp_args:Nc \seq_gpop:NN} % \end{macrocode} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % % % \begin{macro}{\seq_top:NN} % \begin{macro}{\seq_top:cN} % Looking at the top element of the stack without removing it is % done with this operation. % \begin{macrocode} \let_new:NN \seq_top:NN \seq_get:NN \let_new:NN \seq_top:cN \seq_get:cN % \end{macrocode} % \end{macro} % \end{macro} % % % Show token usage: % \begin{macrocode} % %<*showmemory> %\showMemUsage % % \end{macrocode} % % %