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author | Karl Berry <karl@freefriends.org> | 2011-07-31 18:27:06 +0000 |
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committer | Karl Berry <karl@freefriends.org> | 2011-07-31 18:27:06 +0000 |
commit | dac945b204407dae96f70ec228206516093156d7 (patch) | |
tree | 02ca182689947e45dec95e17ba08b503c959bd17 /Master/texmf-dist/source/latex/l3kernel/l3skip.dtx | |
parent | c1840548792cfbc7c9f746da1d53d89b94406e72 (diff) |
l3kernel (5jun11)
git-svn-id: svn://tug.org/texlive/trunk@23282 c570f23f-e606-0410-a88d-b1316a301751
Diffstat (limited to 'Master/texmf-dist/source/latex/l3kernel/l3skip.dtx')
-rw-r--r-- | Master/texmf-dist/source/latex/l3kernel/l3skip.dtx | 1675 |
1 files changed, 1675 insertions, 0 deletions
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3skip.dtx b/Master/texmf-dist/source/latex/l3kernel/l3skip.dtx new file mode 100644 index 00000000000..ecd3ca2e397 --- /dev/null +++ b/Master/texmf-dist/source/latex/l3kernel/l3skip.dtx @@ -0,0 +1,1675 @@ +% \iffalse meta-comment +% +%% File: l3skip.dtx Copyright (C) 2004-2011 Frank Mittelbach, The LaTeX3 Project +%% +%% It may be distributed and/or modified under the conditions of the +%% LaTeX Project Public License (LPPL), either version 1.3c of this +%% license or (at your option) any later version. The latest version +%% of this license is in the file +%% +%% http://www.latex-project.org/lppl.txt +%% +%% This file is part of the "expl3 bundle" (The Work in LPPL) +%% and all files in that bundle must be distributed together. +%% +%% The released version of this bundle is available from CTAN. +%% +%% ----------------------------------------------------------------------- +%% +%% The development version of the bundle can be found at +%% +%% http://www.latex-project.org/svnroot/experimental/trunk/ +%% +%% for those people who are interested. +%% +%%%%%%%%%%% +%% NOTE: %% +%%%%%%%%%%% +%% +%% Snapshots taken from the repository represent work in progress and may +%% not work or may contain conflicting material! We therefore ask +%% people _not_ to put them into distributions, archives, etc. without +%% prior consultation with the LaTeX3 Project. +%% +%% ----------------------------------------------------------------------- +% +%<*driver|package> +\RequirePackage{l3names} +\GetIdInfo$Id: l3skip.dtx 2478 2011-06-19 21:34:23Z joseph $ + {L3 Experimental dimensions and skips} +%</driver|package> +%<*driver> +\documentclass[full]{l3doc} +\begin{document} + \DocInput{\jobname.dtx} +\end{document} +%</driver> +% \fi +% +% \title{^^A +% The \pkg{l3skip} package\\ Dimensions and skips^^A +% \thanks{This file describes v\ExplFileVersion, +% last revised \ExplFileDate.}^^A +% } +% +% \author{^^A +% The \LaTeX3 Project\thanks +% {^^A +% E-mail: +% \href{mailto:latex-team@latex-project.org} +% {latex-team@latex-project.org}^^A +% }^^A +% } +% +% \date{Released \ExplFileDate} +% +% \maketitle +% +% \begin{documentation} +% +% \LaTeX3 provides two general length variables: \texttt{dim} and +% \texttt{skip}. Lengths stored as \texttt{dim} variables have a fixed +% length, whereas \texttt{skip} lengths have a rubber (stretch/shrink) +% component. In addition, the \texttt{muskip} type is available for +% use in math mode: this is a special form of \texttt{skip} where the +% lengths involved are determined by the current math font (in +% \texttt{mu)}. There are common features in the creation and setting of +% length variables, but for clarity the functions are grouped by variable +% type. +% +% \section{Creating and initialising \texttt{dim} variables} +% +% \begin{function}{\dim_new:N, \dim_new:c} +% \begin{syntax} +% \cs{dim_new:N} \meta{dimension} +% \end{syntax} +% Creates a new \meta{dimension} or raises an error if the name is +% already taken. The declaration is global. The \meta{dimension} +% will initially be equal to $0$\,pt. +% \end{function} +% +% \begin{function}{\dim_zero:N, \dim_zero:c} +% \begin{syntax} +% \cs{dim_zero:N} \meta{dimension} +% \end{syntax} +% Sets \meta{dimension} to $0$\,pt within the scope of the current +% \TeX{} group. +% \end{function} +% +% \begin{function}{\dim_gzero:N, \dim_gzero:c} +% \begin{syntax} +% \cs{dim_gzero:N} \meta{dimension} +% \end{syntax} +% Sets \meta{dimension} to $0$\,pt globally, \emph{i.e.}~not +% restricted by the current \TeX{} group level. +% \end{function} +% +% \section{Setting \texttt{dim} variables} +% +% \begin{function}{\dim_add:Nn, \dim_add:cn} +% \begin{syntax} +% \cs{dim_add:Nn} \meta{dimension} \Arg{dimension expression} +% \end{syntax} +% Adds the result of the \meta{dimension expression} to the current +% content of the \meta{dimension}. This assignment is local. +% \end{function} +% +% \begin{function}{\dim_gadd:Nn, \dim_gadd:cn} +% \begin{syntax} +% \cs{dim_gadd:Nn} \meta{dimension} \Arg{dimension expression} +% \end{syntax} +% Adds the result of the \meta{dimension expression} to the +% current content of the \meta{dimension}. This assignment is global. +% \end{function} +% +% \begin{function}{\dim_set:Nn, \dim_set:cn} +% \begin{syntax} +% \cs{dim_set:Nn} \meta{dimension} \Arg{dimension expression} +% \end{syntax} +% Sets \meta{dimension} to the value of \meta{dimension expression}, which +% must evaluate to a length with units. This assignment is +% restricted to the current \TeX{} group. +% \end{function} +% +% \begin{function}{\dim_gset:Nn, \dim_gset:cn} +% \begin{syntax} +% \cs{dim_gset:Nn} \meta{dimension} \Arg{dimension expression} +% \end{syntax} +% Sets \meta{dimension} to the value of \meta{dimension expression}, which +% must evaluate to a length with units and may include a rubber +% component (for example |1 cm plus 0.5 cm|. This assignment is +% global and is not limited to the current \TeX{} group level. +% \end{function} +% +% \begin{function} +% {\dim_set_eq:NN, \dim_set_eq:cN, \dim_set_eq:Nc, \dim_set_eq:cc} +% \begin{syntax} +% \cs{dim_set_eq:NN} \meta{dimension1} \meta{dimension2} +% \end{syntax} +% Sets the content of \meta{dimension1} equal to that of +% \meta{dimension2}. This assignment is restricted to the current +% \TeX{} group level. +% \end{function} +% +% \begin{function} +% {\dim_gset_eq:NN, \dim_gset_eq:cN, \dim_gset_eq:Nc, \dim_gset_eq:cc} +% \begin{syntax} +% \cs{dim_gset_eq:NN} \meta{dimension1} \meta{dimension2} +% \end{syntax} +% Sets the content of \meta{dimension1} equal to that of \meta{dimension2}. +% This assignment is global and so is not limited by the current +% \TeX{} group level. +% \end{function} +% +% \begin{function}{\dim_set_max:Nn, \dim_set_max:cn} +% \begin{syntax} +% \cs{dim_set_max:Nn} \meta{dimension} \Arg{dimension expression} +% \end{syntax} +% Compares the current value of the \meta{dimension} with that of the +% \meta{dimension expression}, and sets the \meta{dimension} to the +% larger of these two value. This assignment is local to the current +% \TeX{} group. +% \end{function} +% +% \begin{function}{\dim_gset_max:Nn, \dim_gset_max:cn} +% \begin{syntax} +% \cs{dim_gset_max:Nn} \meta{dimension} \Arg{dimension expression} +% \end{syntax} +% Compares the current value of the \meta{dimension} with that of the +% \meta{dimension expression}, and sets the \meta{dimension} to the +% larger of these two value. This assignment is global. +% \end{function} +% +% \begin{function}{\dim_set_min:Nn, \dim_set_min:cn} +% \begin{syntax} +% \cs{dim_set_min:Nn} \meta{dimension} \Arg{dimension expression} +% \end{syntax} +% Compares the current value of the \meta{dimension} with that of the +% \meta{dimension expression}, and sets the \meta{dimension} to the +% smaller of these two value. This assignment is local to the current +% \TeX{} group. +% \end{function} +% +% \begin{function}{\dim_gset_min:Nn, \dim_gset_min:cn} +% \begin{syntax} +% \cs{dim_gset_min:Nn} \meta{dimension} \Arg{dimension expression} +% \end{syntax} +% Compares the current value of the \meta{dimension} with that of the +% \meta{dimension expression}, and sets the \meta{dimension} to the +% smaller of these two value. This assignment is global. +% \end{function} +% +% \begin{function}{\dim_sub:Nn, \dim_sub:cn} +% \begin{syntax} +% \cs{dim_sub:Nn} \meta{dimension} \Arg{dimension expression} +% \end{syntax} +% Subtracts the result of the \meta{dimension expression} to the +% current content of the \meta{dimension}. This assignment is local. +% \end{function} +% +% \begin{function}{\dim_gsub:Nn, \dim_gsub:cn} +% \begin{syntax} +% \cs{dim_gsub:Nn} \meta{dimension} \Arg{dimension expression} +% \end{syntax} +% Subtracts the result of the \meta{dimension expression} to the +% current content of the \meta{dimension}. This assignment is global. +% \end{function} +% +% \section{Utilities for dimension calculations} +% +% \begin{function}[EXP]{\dim_ratio:nn} +% \begin{syntax} +% \cs{dim_ratio:nn} \Arg{dimexpr1} \Arg{dimexpr2} +% \end{syntax} +% Parses the two \meta{dimension expressions} and converts the ratio of +% the two to a form suitable for use inside a \meta{dimension expression}. +% This ratio is then left in the input stream, allowing syntax such as +% \begin{verbatim} +% \dim_set:Nn \l_my_dim +% { 10 pt * \dim_ratio:nn { 5 pt } { 10 pt } } +% \end{verbatim} +% The output of \cs{dim_ratio:nn} on full expansion is a ration expression +% between two integers, with all distances converted to scaled points. +% Thus +% \begin{verbatim} +% \tl_set:Nx \l_my_tl { \dim_ratio:nn { 5 pt } { 10 pt } } +% \tl_show:N \l_my_tl +% \end{verbatim} +% will display |327680/655360| on the terminal. +% \end{function} +% +% \section{Dimension expression conditionals} +% +% \begin{function}[EXP,pTF]{\dim_compare:nNn} +% \begin{syntax} +% \cs{dim_compare_p:nNn} +% ~~\Arg{dimexpr1} \meta{relation} \Arg{dimexpr2} +% \cs{dim_compare:nNnTF} +% ~~\Arg{dimexpr1} \meta{relation} \Arg{dimexpr2} +% ~~\Arg{true code} \Arg{false code} +% \end{syntax} +% This function first evaluates each of the \meta{dimension expressions} +% as described for \cs{dim_eval:n}. The two results are then +% compared using the \meta{relation}: +% \begin{center} +% \begin{tabular}{ll} +% Equal & |=| \\ +% Greater than & |>| \\ +% Less than & |<| \\ +% \end{tabular} +% \end{center} +% The branching versions then leave either \meta{true code} or +% \meta{false code} in the input stream, as appropriate to the truth +% of the test and the variant of the function chosen. The logical +% truth of the test is left in the input stream by the predicate +% version. +% \end{function} +% +% \begin{function}[EXP,pTF]{\dim_compare:n} +% \begin{syntax} +% \cs{dim_compare_p:n} +% ~~\{ \meta{dimexpr1} \meta{relation} \meta{dimexpr2} \} +% \cs{dim_compare:nTF} +% ~~\{ \meta{dimexpr1} \meta{relation} \meta{dimexpr2} \} +% ~~\Arg{true code} \Arg{false code} +% \end{syntax} +% This function first evaluates each of the \meta{dimension expressions} +% as described for \cs{dim_eval:n}. The two results are then +% compared using the \meta{relation}: +% \begin{center} +% \begin{tabular}{ll} +% Equal & |=| or |==| \\ +% Greater than or equal to & |=>| \\ +% Greater than & |>| \\ +% Less than or equal to & |=<| \\ +% Less than & |<| \\ +% Not equal & |!=| \\ +% \end{tabular} +% \end{center} +% The branching versions then leave either \meta{true code} or +% \meta{false code} in the input stream, as appropriate to the truth +% of the test and the variant of the function chosen. The logical +% truth of the test is left in the input stream by the predicate +% version. +% \end{function} +% +% \section{Dimension expression loops} +% +% \begin{function}[EXP]{\dim_do_while:nNnn} +% \begin{syntax} +% \cs{dim_do_while:nNnn} +% ~~\Arg{dimexpr1} \meta{relation} \Arg{dimexpr2} \Arg{code} +% \end{syntax} +% Evaluates the relationship between the two \meta{dimension expressions} +% as described for \cs{dim_compare:nNnTF}, and then places the +% \meta{code} in the input stream if the \meta{relation} is +% \texttt{true}. After the \meta{code} has been processed by \TeX{} the +% test will be repeated, and a loop will occur until the test is +% \texttt{false}. +% \end{function} +% +% \begin{function}[EXP]{\dim_do_until:nNnn} +% \begin{syntax} +% \cs{dim_do_until:nNnn} +% ~~\Arg{dimexpr1} \meta{relation} \Arg{dimexpr2} \Arg{code} +% \end{syntax} +% Evaluates the relationship between the two \meta{dimension expressions} +% as described for \cs{dim_compare:nNnTF}, and then places the +% \meta{code} in the input stream if the \meta{relation} is +% \texttt{false}. After the \meta{code} has been processed by \TeX{} the +% test will be repeated, and a loop will occur until the test is +% \texttt{true}. +% \end{function} +% +% \begin{function}[EXP]{\dim_until_do:nNnn} +% \begin{syntax} +% \cs{dim_until_do:nNnn} +% ~~\Arg{dimexpr1} \meta{relation} \Arg{dimexpr2} \Arg{code} +% \end{syntax} +% Places the \meta{code} in the input stream for \TeX{} to process, and +% then evaluates the relationship between the two +% \meta{dimension expressions} as described for \cs{dim_compare:nNnTF}. +% If the test is \texttt{false} then the \meta{code} will be inserted +% into the input stream again and a loop will occur until the +% \meta{relation} is \texttt{true}. +% \end{function} +% +% \begin{function}[EXP]{\dim_while_do:nNnn} +% \begin{syntax} +% \cs{dim_while_do:nNnn} +% ~~\Arg{dimexpr1} \meta{relation} \Arg{dimexpr2} \Arg{code} +% \end{syntax} +% Places the \meta{code} in the input stream for \TeX{} to process, and +% then evaluates the relationship between the two +% \meta{dimension expressions} as described for \cs{dim_compare:nNnTF}. +% If the test is \texttt{true} then the \meta{code} will be inserted +% into the input stream again and a loop will occur until the +% \meta{relation} is \texttt{false}. +% \end{function} +% +% \begin{function}[EXP]{\dim_do_while:nn} +% \begin{syntax} +% \cs{dim_do_while:nNnn} +% ~~\{ \meta{dimexpr1} \meta{relation} \meta{dimexpr2} \} \Arg{code} +% \end{syntax} +% Evaluates the relationship between the two \meta{dimension expressions} +% as described for \cs{dim_compare:nTF}, and then places the +% \meta{code} in the input stream if the \meta{relation} is +% \texttt{true}. After the \meta{code} has been processed by \TeX{} the +% test will be repeated, and a loop will occur until the test is +% \texttt{false}. +% \end{function} +% +% \begin{function}[EXP]{\dim_do_until:nn} +% \begin{syntax} +% \cs{dim_do_until:nn} +% ~~\{ \meta{dimexpr1} \meta{relation} \meta{dimexpr2} \} \Arg{code} +% \end{syntax} +% Evaluates the relationship between the two \meta{dimension expressions} +% as described for \cs{dim_compare:nTF}, and then places the +% \meta{code} in the input stream if the \meta{relation} is +% \texttt{false}. After the \meta{code} has been processed by \TeX{} the +% test will be repeated, and a loop will occur until the test is +% \texttt{true}. +% \end{function} +% +% \begin{function}[EXP]{\dim_until_do:nn} +% \begin{syntax} +% \cs{dim_until_do:nn} +% ~~\{ \meta{dimexpr1} \meta{relation} \meta{dimexpr2} \} \Arg{code} +% \end{syntax} +% Places the \meta{code} in the input stream for \TeX{} to process, and +% then evaluates the relationship between the two +% \meta{dimension expressions} as described for \cs{dim_compare:nTF}. +% If the test is \texttt{false} then the \meta{code} will be inserted +% into the input stream again and a loop will occur until the +% \meta{relation} is \texttt{true}. +% \end{function} +% +% \begin{function}[EXP]{\dim_while_do:nn} +% \begin{syntax} +% \cs{dim_while_do:nn} +% ~~\{ \meta{dimexpr1} \meta{relation} \meta{dimexpr2} \} \Arg{code} +% \end{syntax} +% Places the \meta{code} in the input stream for \TeX{} to process, and +% then evaluates the relationship between the two +% \meta{dimension expressions} as described for \cs{dim_compare:nTF}. +% If the test is \texttt{true} then the \meta{code} will be inserted +% into the input stream again and a loop will occur until the +% \meta{relation} is \texttt{false}. +% \end{function} +% +% \section{Using \texttt{dim} expressions and variables} +% +% \begin{function}[EXP]{\dim_eval:n} +% \begin{syntax} +% \cs{dim_eval:n} \Arg{dimension expression} +% \end{syntax} +% Evaluates the \meta{dimension expression}, expanding any +% dimensions and token list variables within the \meta{expression} +% to their content (without requiring \cs{dim_use:N}/\cs{tl_use:N}) +% and applying the standard mathematical rules. The result of the +% calculation is left in the input stream as a +% \meta{dimension denotation} after two expansions. This will be +% expressed in points (\texttt{pt}), and will require suitable +% termination if used in a \TeX{}-style assignment as it is \emph{not} +% an \meta{internal dimension}. +% \end{function} +% +% \begin{function}[EXP]{\dim_use:N, \dim_use:c} +% \begin{syntax} +% \cs{dim_use:N} \meta{dimension} +% \end{syntax} +% Recovers the content of a \meta{dimension} and places it directly +% in the input stream. An error will be raised if the variable does +% not exist or if it is invalid. Can be omitted in places where a +% \meta{dimension} is required (such as in the argument of +% \cs{dim_eval:n}). +% \begin{texnote} +% \cs{dim_use:N} is the \TeX{} primitive \cs{the}: this is one of +% several \LaTeX3 names for this primitive. +% \end{texnote} +% \end{function} +% +% \section{Viewing \texttt{dim} variables} +% +% \begin{function}{\dim_show:N, \dim_show:c} +% \begin{syntax} +% \cs{dim_show:N} \meta{dimension} +% \end{syntax} +% Displays the value of the \meta{dimension} on the terminal. +% \end{function} +% +% \section{Constant dimensions} +% +% \begin{variable}{\c_max_dim} +% The maximum value that can be stored as a dimension or skip (these +% are equivalent). +% \end{variable} +% +% \begin{variable}{\c_zero_dim} +% A zero length as a dimension or a skip (these are equivalent). +% \end{variable} +% +% \section{Scratch dimensions} +% +% \begin{variable}{\l_tmpa_dim, \l_tmpb_dim, \l_tmpc_dim} +% Scratch dimension 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_dim, \g_tmpb_dim} +% Scratch dimension 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} +% +% \section{Creating and initialising \texttt{skip} variables} +% +% \begin{function}{\skip_new:N, \skip_new:c} +% \begin{syntax} +% \cs{skip_new:N} \meta{skip} +% \end{syntax} +% Creates a new \meta{skip} or raises an error if the name is +% already taken. The declaration is global. The \meta{skip} +% will initially be equal to $0$\,pt. +% \end{function} +% +% \begin{function}{\skip_zero:N, \skip_zero:c} +% \begin{syntax} +% \cs{skip_zero:N} \meta{skip} +% \end{syntax} +% Sets \meta{skip} to $0$\,pt within the scope of the current +% \TeX{} group. +% \end{function} +% +% \begin{function}{\skip_gzero:N, \skip_gzero:c} +% \begin{syntax} +% \cs{skip_gzero:N} \meta{skip} +% \end{syntax} +% Sets \meta{skip} to $0$\,pt globally, \emph{i.e.}~not +% restricted by the current \TeX{} group level. +% \end{function} +% +% \section{Setting \texttt{skip} variables} +% +% \begin{function}{\skip_add:Nn, \skip_add:cn} +% \begin{syntax} +% \cs{skip_add:Nn} \meta{skip} \Arg{skip expression} +% \end{syntax} +% Adds the result of the \meta{skip expression} to the current +% content of the \meta{skip}. This assignment is local. +% \end{function} +% +% \begin{function}{\skip_gadd:Nn, \skip_gadd:cn} +% \begin{syntax} +% \cs{skip_gadd:Nn} \meta{skip} \Arg{skip expression} +% \end{syntax} +% Adds the result of the \meta{skip expression} to the +% current content of the \meta{skip}. This assignment is global. +% \end{function} +% +% \begin{function}{\skip_set:Nn, \skip_set:cn} +% \begin{syntax} +% \cs{skip_set:Nn} \meta{skip} \Arg{skip expression} +% \end{syntax} +% Sets \meta{skip} to the value of \meta{skip expression}, which +% must evaluate to a length with units and may include a rubber +% component (for example |1 cm plus 0.5 cm|. This assignment is +% restricted to the current \TeX{} group. +% \end{function} +% +% \begin{function} +% {\skip_gset_eq:NN, \skip_gset_eq:cN, \skip_gset_eq:Nc, \skip_gset_eq:cc} +% \begin{syntax} +% \cs{skip_gset_eq:NN} \meta{skip1} \meta{skip2} +% \end{syntax} +% Sets the content of \meta{skip1} equal to that of \meta{skip2}. +% This assignment is global and so is not limited by the current +% \TeX{} group level. +% \end{function} +% +% \begin{function}{\skip_gset:Nn, \skip_gset:cn} +% \begin{syntax} +% \cs{skip_gset:Nn} \meta{skip} \Arg{skip expression} +% \end{syntax} +% Sets \meta{skip} to the value of \meta{skip expression}, which +% must evaluate to a length with units and may include a rubber +% component (for example |1 cm plus 0.5 cm|. This assignment is +% global and is not limited to the current \TeX{} group level. +% \end{function} +% +% \begin{function} +% {\skip_set_eq:NN, \skip_set_eq:cN, \skip_set_eq:Nc, \skip_set_eq:cc} +% \begin{syntax} +% \cs{skip_set_eq:NN} \meta{skip1} \meta{skip2} +% \end{syntax} +% Sets the content of \meta{skip1} equal to that of +% \meta{skip2}. This assignment is restricted to the current +% \TeX{} group level. +% \end{function} +% +% \begin{function}{\skip_sub:Nn, \skip_sub:cn} +% \begin{syntax} +% \cs{skip_sub:Nn} \meta{skip} \Arg{skip expression} +% \end{syntax} +% Subtracts the result of the \meta{skip expression} to the +% current content of the \meta{skip}. This assignment is local. +% \end{function} +% +% \begin{function}{\skip_gsub:Nn, \skip_gsub:cn} +% \begin{syntax} +% \cs{skip_gsub:Nn} \meta{skip} \Arg{skip expression} +% \end{syntax} +% Subtracts the result of the \meta{skip expression} to the +% current content of the \meta{skip}. This assignment is global. +% \end{function} +% +% \section{Skip expression conditionals} +% +% \begin{function}[EXP,pTF]{\skip_if_eq:nn} +% \begin{syntax} +% \cs{skip_if_eq_p:nn} +% ~~\Arg{skipexpr1} \Arg{skipexpr2} +% \cs{dim_compare:nTF} +% ~~\Arg{skipexpr1} \Arg{skipexpr2} +% ~~\Arg{true code} \Arg{false code} +% \end{syntax} +% This function first evaluates each of the +% \meta{skip expressions} as described for \cs{skip_eval:n}. +% The two results are then compared for exact equality, +% \emph{i.e.}~both the fixed and rubber components must be the same +% for the test to be true. The branching versions then leave either +% \meta{true code} or \meta{false code} in the input stream, as +% appropriate to the truth of the test and the variant of the function +% chosen. The logical truth of the test is left in the input stream by +% the predicate version. +% \end{function} +% +% \begin{function}[EXP,pTF]{\skip_if_infinite_glue:n} +% \begin{syntax} +% \cs{skip_if_infinite_glue_p:n} \Arg{skipexpr} +% \cs{skip_if_infinite_glue:nTF} \Arg{skipexpr} +% ~~\Arg{true code} \Arg{false code} +% \end{syntax} +% Evaluates the \meta{skip expression} as described for \cs{skip_eval:n}, +% and then tests if this contains an infinite stretch or shrink +% component (or both). +% The branching versions then leave either \meta{true code} or +% \meta{false code} in the input stream, as appropriate to the truth +% of the test and the variant of the function chosen. The logical +% truth of the test is left in the input stream by the predicate +% \end{function} +% +% \section{Using \texttt{skip} expressions and variables} +% +% \begin{function}[EXP]{\skip_eval:n} +% \begin{syntax} +% \cs{skip_eval:n} \Arg{skip expression} +% \end{syntax} +% Evaluates the \meta{skip expression}, expanding any skips +% and token list variables within the \meta{expression} +% to their content (without requiring \cs{skip_use:N}/\cs{tl_use:N}) +% and applying the standard mathematical rules. The result of the +% calculation is left in the input stream as a \meta{glue denotation} +% after two expansions. This will be expressed in points (\texttt{pt}), +% and will require suitable termination if used in a \TeX{}-style +% assignment as it is \emph{not} an \meta{internal glue}. +% \end{function} +% +% \begin{function}[EXP]{\skip_use:N, \skip_use:c} +% \begin{syntax} +% \cs{skip_use:N} \meta{skip} +% \end{syntax} +% Recovers the content of a \meta{skip} and places it directly +% in the input stream. An error will be raised if the variable does +% not exist or if it is invalid. Can be omitted in places where a +% \meta{dimension} is required (such as in the argument of +% \cs{skip_eval:n}). +% \begin{texnote} +% \cs{skip_use:N} is the \TeX{} primitive \cs{the}: this is one of +% several \LaTeX3 names for this primitive. +% \end{texnote} +% \end{function} +% +% \section{Viewing \texttt{skip} variables} +% +% \begin{function}{\skip_show:N, \skip_show:c} +% \begin{syntax} +% \cs{skip_show:N} \meta{skip} +% \end{syntax} +% Displays the value of the \meta{skip} on the terminal. +% \end{function} +% +% \section{Constant skips} +% +% \begin{variable}{\c_max_skip} +% The maximum value that can be stored as a dimension or skip (these +% are equivalent). +% \end{variable} +% +% \begin{variable}{\c_zero_skip} +% A zero length as a dimension or a skip (these are equivalent). +% \end{variable} +% +% \section{Scratch skips} +% +% \begin{variable}{\l_tmpa_skip, \l_tmpb_skip, \l_tmpc_skip} +% Scratch skip 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_skip, \g_tmpb_skip} +% Scratch skip 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} +% +% \section{Creating and initialising \texttt{muskip} variables} +% +% \begin{function}{\muskip_new:N, \muskip_new:c} +% \begin{syntax} +% \cs{muskip_new:N} \meta{muskip} +% \end{syntax} +% Creates a new \meta{muskip} or raises an error if the name is +% already taken. The declaration is global. The \meta{muskip} +% will initially be equal to $0$\,mu. +% \end{function} +% +% \begin{function}{\muskip_zero:N, \muskip_zero:c} +% \begin{syntax} +% \cs{skip_zero:N} \meta{muskip} +% \end{syntax} +% Sets \meta{muskip} to $0$\,mu within the scope of the current +% \TeX{} group. +% \end{function} +% +% \begin{function}{\muskip_gzero:N, \muskip_gzero:c} +% \begin{syntax} +% \cs{muskip_gzero:N} \meta{muskip} +% \end{syntax} +% Sets \meta{muskip} to $0$\,mu globally, \emph{i.e.}~not +% restricted by the current \TeX{} group level. +% \end{function} +% +% \section{Setting \texttt{muskip} variables} +% +% \begin{function}{\muskip_add:Nn, \muskip_add:cn} +% \begin{syntax} +% \cs{muskip_add:Nn} \meta{muskip} \Arg{muskip expression} +% \end{syntax} +% Adds the result of the \meta{muskip expression} to the current +% content of the \meta{muskip}. This assignment is local. +% \end{function} +% +% \begin{function}{\muskip_gadd:Nn, \muskip_gadd:cn} +% \begin{syntax} +% \cs{muskip_gadd:Nn} \meta{muskip} \Arg{muskip expression} +% \end{syntax} +% Adds the result of the \meta{muskip expression} to the +% current content of the \meta{muskip}. This assignment is global. +% \end{function} +% +% \begin{function}{\muskip_set:Nn, \muskip_set:cn} +% \begin{syntax} +% \cs{muskip_set:Nn} \meta{muskip} \Arg{muskip expression} +% \end{syntax} +% Sets \meta{muskip} to the value of \meta{muskip expression}, which +% must evaluate to a math length with units and may include a rubber +% component (for example |1 mu plus 0.5 mu|. This assignment is +% restricted to the current \TeX{} group. +% \end{function} +% +% \begin{function}{\muskip_gset:Nn, \muskip_gset:cn} +% \begin{syntax} +% \cs{muskip_gset:Nn} \meta{muskip} \Arg{muskip expression} +% \end{syntax} +% Sets \meta{muskip} to the value of \meta{muskip expression}, which +% must evaluate to a math length with units and may include a rubber +% component (for example |1 mu plus 0.5 mu|. This assignment is +% global and is not limited to the current \TeX{} group level. +% \end{function} +% +% \begin{function} +% { +% \muskip_set_eq:NN, \muskip_set_eq:cN, +% \muskip_set_eq:Nc, \muskip_set_eq:cc +% } +% \begin{syntax} +% \cs{muskip_set_eq:NN} \meta{muskip1} \meta{muskip2} +% \end{syntax} +% Sets the content of \meta{muskip1} equal to that of +% \meta{muskip2}. This assignment is restricted to the current +% \TeX{} group level. +% \end{function} +% +% \begin{function} +% { +% \muskip_gset_eq:NN, \muskip_gset_eq:cN, +% \muskip_gset_eq:Nc, \muskip_gset_eq:cc +% } +% \begin{syntax} +% \cs{muskip_gset_eq:NN} \meta{muskip1} \meta{muskip2} +% \end{syntax} +% Sets the content of \meta{muskip1} equal to that of \meta{muskip2}. +% This assignment is global and so is not limited by the current +% \TeX{} group level. +% \end{function} +% +% \begin{function}{\muskip_sub:Nn, \muskip_sub:cn} +% \begin{syntax} +% \cs{muskip_sub:Nn} \meta{muskip} \Arg{muskip expression} +% \end{syntax} +% Subtracts the result of the \meta{muskip expression} to the +% current content of the \meta{skip}. This assignment is local. +% \end{function} +% +% \begin{function}{\muskip_gsub:Nn, \muskip_gsub:cn} +% \begin{syntax} +% \cs{muskip_gsub:Nn} \meta{muskip} \Arg{muskip expression} +% \end{syntax} +% Subtracts the result of the \meta{muskip expression} to the +% current content of the \meta{muskip}. This assignment is global. +% \end{function} +% +% \section{Using \texttt{muskip} expressions and variables} +% +% \begin{function}[EXP]{\muskip_eval:n} +% \begin{syntax} +% \cs{muskip_eval:n} \Arg{muskip expression} +% \end{syntax} +% Evaluates the \meta{muskip expression}, expanding any skips +% and token list variables within the \meta{expression} +% to their content (without requiring \cs{muskip_use:N}/\cs{tl_use:N}) +% and applying the standard mathematical rules. The result of the +% calculation is left in the input stream as a \meta{muglue denotation} +% after two expansions. This will be expressed in \texttt{mu}, +% and will require suitable termination if used in a \TeX{}-style +% assignment as it is \emph{not} an \meta{internal muglue}. +% \end{function} +% +% \begin{function}[EXP]{\muskip_use:N, \muskip_use:c} +% \begin{syntax} +% \cs{muskip_use:N} \meta{muskip} +% \end{syntax} +% Recovers the content of a \meta{skip} and places it directly +% in the input stream. An error will be raised if the variable does +% not exist or if it is invalid. Can be omitted in places where a +% \meta{dimension} is required (such as in the argument of +% \cs{muskip_eval:n}). +% \begin{texnote} +% \cs{muskip_use:N} is the \TeX{} primitive \cs{the}: this is one of +% several \LaTeX3 names for this primitive. +% \end{texnote} +% \end{function} +% +% \section{Inserting skips into the output} +% +% \begin{function}{\skip_horizontal:N, \skip_horizontal:c, \skip_horizontal:n} +% \begin{syntax} +% \cs{skip_horizontal:N} \meta{skip} +% \cs{skip_horizontal:n} \Arg{skipexpr} +% \end{syntax} +% Inserts a horizontal \meta{skip} into the current list. +% \begin{texnote} +% \cs{skip_horizontal:N} is the \TeX{} primitive \cs{hskip} renamed. +% \end{texnote} +% \end{function} +% +% \begin{function}{\skip_vertical:N, \skip_vertical:c, \skip_vertical:n} +% \begin{syntax} +% \cs{skip_vertical:N} \meta{skip} +% \cs{skip_vertical:n} \Arg{skipexpr} +% \end{syntax} +% Inserts a vertical \meta{skip} into the current list. +% \begin{texnote} +% \cs{skip_vertical:N} is the \TeX{} primitive \cs{vskip} renamed. +% \end{texnote} +% \end{function} +% +% \section{Viewing \texttt{muskip} variables} +% +% \begin{function}{\muskip_show:N, \muskip_show:c} +% \begin{syntax} +% \cs{muskip_show:N} \meta{muskip} +% \end{syntax} +% Displays the value of the \meta{muskip} on the terminal. +% \end{function} +% +% \section{Internal functions} +% +% \begin{function}{\if_dim:w} +% \begin{syntax} +% \cs{if_dim:w} \meta{dimen1} \meta{relation} \meta{dimen1} +% ~~\meta{true code} +% \cs{else:} +% ~~\meta{false} +% \cs{fi:} +% \end{syntax} +% Compare two dimensions. The \meta{relation} is one of +% |<|, |=| or |>| with category code $12$. +% \begin{texnote} +% This is the \TeX{} primitive \cs{ifdim}. +% \end{texnote} +% \end{function} +% +% \begin{function}[EXP]{\dim_eval:w, \dim_eval_end:} +% \begin{syntax} +% \cs{dim_eval:w} \meta{dimexpr} \cs{dim_eval_end:} +% \end{syntax} +% Evaluates \meta{dimension expression} as described for \cs{dim_eval:n}. +% The evaluation stops when an unexpandable token which is not a valid +% part of a dimension is read or when \cs{dim_eval_end:} is +% reached. The latter is gobbled by the scanner mechanism: +% \cs{dim_eval_end:} itself is unexpandable but used correctly +% the entire construct is expandable. +% \begin{texnote} +% This is the \eTeX{} primitive \cs{dimexpr}. +% \end{texnote} +% \end{function} +% +% \section{Experimental skip functions} +% +% \begin{function}{\skip_split_finite_else_action:nnNN} +% \begin{syntax} +% \cs{skip_split_finite_else_action:nnNN} \Arg{skipexpr} \Arg{action} +% ~~\meta{dimen1} \meta{dimen2} +% \end{syntax} +% Checks if the \meta{skipexpr} contains finite glue. If it does then it +% assigns +% \meta{dimen1} the stretch component and \meta{dimen2} the shrink +% component. If +% it contains infinite glue set \meta{dimen1} and \meta{dimen2} to $0$\,pt +% and place |#2| into the input stream: this is usually an error or +% warning message of some sort. +% \end{function} +% +% \end{documentation} +% +% \begin{implementation} +% +% \section{\pkg{l3skip} implementation} +% +% \begin{macrocode} +%<*initex|package> +% \end{macrocode} +% +% \begin{macrocode} +%<*package> +\ProvidesExplPackage + {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription} +\package_check_loaded_expl: +%</package> +% \end{macrocode} +% +% \subsection{Length primitives renamed} +% +% \begin{macro}{\if_dim:w} +% \begin{macro}{\dim_eval:w} +% \begin{macro}{\dim_eval_end:} +% Primitives renamed. +% \begin{macrocode} +\cs_new_eq:NN \if_dim:w \tex_ifdim:D +\cs_new_eq:NN \dim_eval:w \etex_dimexpr:D +\cs_new_eq:NN \dim_eval_end: \tex_relax:D +% \end{macrocode} +% \end{macro} +% \end{macro} +% \end{macro} +% +% \subsection{Creating and initialising \texttt{dim} variables} +% +% \begin{macro}{\dim_new:N,\dim_new:c} +% Allocating \meta{dim} registers \ldots +% \begin{macrocode} +%<*initex> +\alloc_new:nnnN { dim } \c_zero \c_max_register_int \tex_dimendef:D +%</initex> +%<*package> +\cs_new_protected_nopar:Npn \dim_new:N #1 + { + \chk_if_free_cs:N #1 + \newdimen #1 + } +%</package> +\cs_generate_variant:Nn \dim_new:N { c } +% \end{macrocode} +% \end{macro} +% +% \begin{macro}{\dim_zero:N, \dim_zero:c} +% \begin{macro}{\dim_gzero:N, \dim_gzero:c} +% Reset the register to zero. +% \begin{macrocode} +\cs_new_protected_nopar:Npn \dim_zero:N #1 { #1 \c_zero_dim } +\cs_new_protected_nopar:Npn \dim_gzero:N { \pref_global:D \dim_zero:N } +\cs_generate_variant:Nn \dim_zero:N { c } +\cs_generate_variant:Nn \dim_gzero:N { c } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \subsection{Setting \texttt{dim} variables} +% +% \begin{macro}{\dim_set:Nn, \dim_set:cn} +% \begin{macro}{\dim_gset:Nn, \dim_gset:cn} +% Setting dimensions is easy enough. +% \begin{macrocode} +\cs_new_protected_nopar:Npn \dim_set:Nn #1#2 + { #1 ~ \dim_eval:w #2 \dim_eval_end: } +\cs_new_protected_nopar:Npn \dim_gset:Nn { \pref_global:D \dim_set:Nn } +\cs_generate_variant:Nn \dim_set:Nn { c } +\cs_generate_variant:Nn \dim_gset:Nn { c } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \begin{macro}{\dim_set_eq:NN,\dim_set_eq:cN, \dim_set_eq:Nc,\dim_set_eq:cc} +% \begin{macro} +% {\dim_gset_eq:NN,\dim_gset_eq:cN, \dim_gset_eq:Nc,\dim_gset_eq:cc} +% All straightforward. +% \begin{macrocode} +\cs_new_protected_nopar:Npn \dim_set_eq:NN #1#2 { #1 = #2 } +\cs_generate_variant:Nn \dim_set_eq:NN { c } +\cs_generate_variant:Nn \dim_set_eq:NN { Nc , cc } +\cs_new_protected_nopar:Npn \dim_gset_eq:NN #1#2 { \pref_global:D #1 = #2 } +\cs_generate_variant:Nn \dim_gset_eq:NN { c } +\cs_generate_variant:Nn \dim_gset_eq:NN { Nc , cc } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \begin{macro}{\dim_set_max:Nn, \dim_set_max:cn} +% \begin{macro}{\dim_set_min:Nn, \dim_set_min:cn} +% \begin{macro}{\dim_gset_max:Nn, \dim_gset_max:cn} +% \begin{macro}{\dim_gset_min:Nn, \dim_gset_min:cn} +% Setting maximum and minimum values is simply a case of so build-in +% comparison. This only applies to dimensions as skips are not ordered. +% \begin{macrocode} +\cs_new_protected_nopar:Npn \dim_set_max:Nn #1#2 + { \dim_compare:nNnT {#1} < {#2} { \dim_set:Nn #1 {#2} } } +\cs_new_protected_nopar:Npn \dim_gset_max:Nn #1#2 + { \dim_compare:nNnT {#1} < {#2} { \dim_gset:Nn #1 {#2} } } +\cs_new_protected_nopar:Npn \dim_set_min:Nn #1#2 + { \dim_compare:nNnT {#1} > {#2} { \dim_set:Nn #1 {#2} } } +\cs_new_protected_nopar:Npn \dim_gset_min:Nn #1#2 + { \dim_compare:nNnT {#1} > {#2} { \dim_gset:Nn #1 {#2} } } +\cs_generate_variant:Nn \dim_set_max:Nn { c } +\cs_generate_variant:Nn \dim_gset_max:Nn { c } +\cs_generate_variant:Nn \dim_set_min:Nn { c } +\cs_generate_variant:Nn \dim_gset_min:Nn { c } +% \end{macrocode} +% \end{macro} +% \end{macro} +% \end{macro} +% \end{macro} +% +% \begin{macro}{\dim_add:Nn, \dim_add:cn} +% \begin{macro}{\dim_gadd:Nn, \dim_gadd:cn} +% \begin{macro}{\dim_sub:Nn, \dim_sub:cn} +% \begin{macro}{\dim_gsub:Nn, \dim_gsub:cn} +% Using |by| here deals with the (incorrect) case |\dimen123|. +% \begin{macrocode} +\cs_new_protected_nopar:Npn \dim_add:Nn #1#2 + { \tex_advance:D #1 by \dim_eval:w #2 \dim_eval_end: } +\cs_new_protected_nopar:Npn \dim_gadd:Nn { \pref_global:D \dim_add:Nn } +\cs_generate_variant:Nn \dim_add:Nn { c } +\cs_generate_variant:Nn \dim_gadd:Nn { c } +\cs_new_protected_nopar:Npn \dim_sub:Nn #1#2 + { \tex_advance:D #1 by - \dim_eval:w #2 \dim_eval_end: } +\cs_new_protected_nopar:Npn \dim_gsub:Nn { \pref_global:D \dim_sub:Nn } +\cs_generate_variant:Nn \dim_sub:Nn { c } +\cs_generate_variant:Nn \dim_gsub:Nn { c } +% \end{macrocode} +% \end{macro} +% \end{macro} +% \end{macro} +% \end{macro} +% +% \subsection{Utilities for dimension calculations} +% +% \begin{macro}{\dim_ratio:nn} +% \begin{macro}[aux]{\dim_ratio_aux:n} +% With dimension expressions, something like |10 pt * ( 5 pt / 10 pt )| will +% not work. Instead, the ratio part needs to be converted to an integer +% expression. Using \cs{int_value:w} forces everything into |sp|, avoiding +% any decimal parts. +% \begin{macrocode} +\cs_new_nopar:Npn \dim_ratio:nn #1#2 + { \dim_ratio_aux:n {#1} / \dim_ratio_aux:n {#2} } +\cs_new_nopar:Npn \dim_ratio_aux:n #1 + { \exp_after:wN \int_value:w \dim_eval:w #1 \dim_eval_end: } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \subsection{Dimension expression conditionals} +% +% \begin{macro}{\dim_compare_p:nNn} +% \begin{macro}[TF]{\dim_compare:nNn} +% \begin{macrocode} +\prg_new_conditional:Npnn \dim_compare:nNn #1#2#3 { p , T , F , TF } + { + \if_dim:w \dim_eval:w #1 #2 \dim_eval:w #3 \dim_eval_end: + \prg_return_true: \else: \prg_return_false: \fi: + } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \begin{macro}[pTF]{\dim_compare:n} +% \begin{macro}[aux]{\dim_compare_aux:wNN} +% \begin{macro}[aux]{\dim_compare_<:nw} +% \begin{macro}[aux]{\dim_compare_=:nw} +% \begin{macro}[aux]{\dim_compare_>:nw} +% \begin{macro}[aux]{\dim_compare_==:nw} +% \begin{macro}[aux]{\dim_compare_<=:nw} +% \begin{macro}[aux]{\dim_compare_!=:nw} +% \begin{macro}[aux]{\dim_compare_>=:nw} +% [This code plus comments are adapted from the \cs{int_compare:nTF} +% function.] +% Comparison tests using a simple syntax where only one set of braces +% is required and additional operators such as |!=| and |>=| are +% supported. First some notes on the idea behind this. We wish to +% support writing code like +% \begin{verbatim} +% \dim_compare_p:n { 5mm + \l_tmpa_dim >= 4pt - \l_tmpb_dim } +% \end{verbatim} +% In other words, we want to somehow add the missing |\dim_eval:w| +% where required. We can start evaluating from the left using +% |\dim_use:N \dim_eval:w|, and we know that since the relation +% symbols |<|, |>|, |=| and |!| are not allowed in such expressions, +% they will terminate the expression. Therefore, we first let \TeX{} +% evaluate this left hand side of the (in)equality. +% +% Eventually, we will convert the relation symbol to the appropriate +% version of \cs{if_dim:w}, and add \cs{dim_eval:w} after it. We +% optimize by placing the end-code already here: this avoids needless +% grabbing of arguments later. +% \begin{macrocode} +\prg_new_conditional:Npnn \dim_compare:n #1 { p , T , F , TF } + { + \exp_after:wN \dim_compare_aux:wNN \dim_use:N \dim_eval:w #1 + \dim_eval_end: + \prg_return_true: + \else: + \prg_return_false: + \fi: + } +% \end{macrocode} +% +% Contrarily to the case of integers, where we have to remove the +% result in order to access the relation, \cs{dim_use:N} nicely +% produces a result which ends in |pt|. We can thus use a delimited +% argument to find the relation. \cs{tl_to_str:n} is needed to +% convert |pt| to \enquote{other} characters. +% +% The relation might be one character, |#2|, or two characters |#2#3|. +% We support the following forms: |=|, |<|, |>| and the extended |!=|, +% |==|, |<=| and |>=|. All the extended forms have an extra |=| so we +% check if that is present as well. Then use specific function to +% perform the (unbalanced) test. +% \begin{macrocode} +\exp_args:Nno \use:nn + { \cs_new:Npn \dim_compare_aux:wNN #1 } + { \tl_to_str:n { pt } } + #2 #3 + { + \use:c + { + dim_compare_ #2 + \if_meaning:w = #3 = \fi: + :nw + } + { #1 pt } #3 + } +% \end{macrocode} +% Here, \cs{dim_eval:w} will begin the right hand side of a dimension +% comparison (with \cs{if_dim:w}), closed cleanly by the trailing tokens +% we put in the definition of \cs{dim_compare:n}. +% +% The actual comparisons take as a first argument the left-hand side +% of the comparison (a length). In the case of normal comparisons, +% just place the relevant \cs{if_dim:w}, with a trailing \cs{dim_eval:w} +% to evaluate the right hand side. For extended comparisons, remove +% the trailing |=| that we left, before evaluating with \cs{dim_eval:w}. +% In both cases, the expansion of \cs{dim_eval:w} is stopped properly, +% and the conditional ended correctly by the tokens we put in the +% definition of \cs{dim_compare:n}. +% +% Equal, less than and greater than are straighforward. +% \begin{macrocode} +\cs_new:cpn { dim_compare_<:nw } #1 { \if_dim:w #1 < \dim_eval:w } +\cs_new:cpn { dim_compare_=:nw } #1 { \if_dim:w #1 = \dim_eval:w } +\cs_new:cpn { dim_compare_>:nw } #1 { \if_dim:w #1 > \dim_eval:w } +% \end{macrocode} +% For the extended syntax |==|, we remove |#2|, trailing |=| sign, +% and otherwise act as for |=|. +% \begin{macrocode} +\cs_new:cpn {dim_compare_==:nw} #1#2 { \if_dim:w #1 = \dim_eval:w } +% \end{macrocode} +% +% Not equal, greater than or equal, less than or equal follow the +% same scheme as the extended equality syntax, with an additional +% \cs{reverse_if:N} to get the opposite of their \enquote{simple} +% analog. +% \begin{macrocode} +\cs_new:cpn {dim_compare_<=:nw} #1#2 {\reverse_if:N \if_dim:w #1 > \dim_eval:w} +\cs_new:cpn {dim_compare_!=:nw} #1#2 {\reverse_if:N \if_dim:w #1 = \dim_eval:w} +\cs_new:cpn {dim_compare_>=:nw} #1#2 {\reverse_if:N \if_dim:w #1 < \dim_eval:w} +% \end{macrocode} +% \end{macro} +% \end{macro} +% \end{macro} +% \end{macro} +% \end{macro} +% \end{macro} +% \end{macro} +% \end{macro} +% \end{macro} +% +% +% +% \subsection{Dimension expression loops} +% +% \begin{macro}{\dim_while_do:nn} +% \begin{macro}{\dim_until_do:nn} +% \begin{macro}{\dim_do_while:nn} +% \begin{macro}{\dim_do_until:nn} +% |while_do| and |do_while| functions for dimensions. Same as for the +% |int| type only the names have changed. +% \begin{macrocode} +\cs_set:Npn \dim_while_do:nn #1#2 + { + \dim_compare:nT {#1} + { + #2 + \dim_while_do:nn {#1} {#2} + } + } +\cs_set:Npn \dim_until_do:nn #1#2 + { + \dim_compare:nF {#1} + { + #2 + \dim_until_do:nn {#1} {#2} + } + } +\cs_set:Npn \dim_do_while:nn #1#2 + { + #2 + \dim_compare:nT {#1} + { \dim_do_while:nNnn {#1} {#2} } + } +\cs_set:Npn \dim_do_until:nn #1#2 + { + #2 + \dim_compare:nF {#1} + { \dim_do_until:nn {#1} {#2} } + } +% \end{macrocode} +% \end{macro} +% \end{macro} +% \end{macro} +% \end{macro} +% +% \begin{macro}{\dim_while_do:nNnn} +% \begin{macro}{\dim_until_do:nNnn} +% \begin{macro}{\dim_do_while:nNnn} +% \begin{macro}{\dim_do_until:nNnn} +% |while_do| and |do_while| functions for dimensions. Same as for the +% |int| type only the names have changed. +% \begin{macrocode} +\cs_set:Npn \dim_while_do:nNnn #1#2#3#4 + { + \dim_compare:nNnT {#1} #2 {#3} + { + #4 + \dim_while_do:nNnn {#1} #2 {#3} {#4} + } + } +\cs_set:Npn \dim_until_do:nNnn #1#2#3#4 + { + \dim_compare:nNnF {#1} #2 {#3} + { + #4 + \dim_until_do:nNnn {#1} #2 {#3} {#4} + } + } +\cs_set:Npn \dim_do_while:nNnn #1#2#3#4 + { + #4 + \dim_compare:nNnT {#1} #2 {#3} + { \dim_do_while:nNnn {#1} #2 {#3} {#4} } + } +\cs_set:Npn \dim_do_until:nNnn #1#2#3#4 + { + #4 + \dim_compare:nNnF {#1} #2 {#3} + { \dim_do_until:nNnn {#1} #2 {#3} {#4} } + } +% \end{macrocode} +% \end{macro} +% \end{macro} +% \end{macro} +% \end{macro} +% +% \subsection{Using \texttt{dim} expressions and variables} +% +% \begin{macro}{\dim_eval:n} +% Evaluating a dimension expression expandably. +% \begin{macrocode} +\cs_new_nopar:Npn \dim_eval:n #1 + { \dim_use:N \dim_eval:w #1 \dim_eval_end: } +% \end{macrocode} +% \end{macro} +% +% \begin{macro}{\dim_use:N, \dim_use:c} +% Accessing a \meta{dim}. +% \begin{macrocode} +\cs_new_eq:NN \dim_use:N \tex_the:D +\cs_generate_variant:Nn \dim_use:N { c } +% \end{macrocode} +% \end{macro} +% +% \subsection{Viewing \texttt{dim} variables} +% +% \begin{macro}{\dim_show:N, \dim_show:c} +% Diagnostics. +% \begin{macrocode} +\cs_new_eq:NN \dim_show:N \kernel_register_show:N +\cs_generate_variant:Nn \dim_show:N { c } +% \end{macrocode} +% \end{macro} +% +% \subsection{Constant dimensions} +% +% \begin{variable}{\c_zero_dim} +% \begin{variable}{\c_max_dim} +% The source for these depends on whether we are in package mode. +% \begin{macrocode} +%<*initex> +\dim_new:N \c_zero_dim +\dim_new:N \c_max_dim +\dim_set:Nn \c_max_dim { 16383.99999 pt } +%</initex> +%<*package> +\cs_new_eq:NN \c_zero_dim \z@ +\cs_new_eq:NN \c_max_dim \maxdimen +%</package> +% \end{macrocode} +% \end{variable} +% \end{variable} +% +% \subsection{Scratch dimensions} +% +% \begin{variable}{\l_tmpa_dim, \l_tmpb_dim, \l_tmpc_dim} +% \begin{variable}{\g_tmpa_dim, \g_tmpb_dim} +% We provide three local and two global scratch registers, maybe we +% need more or less. +% \begin{macrocode} +\dim_new:N \l_tmpa_dim +\dim_new:N \l_tmpb_dim +\dim_new:N \l_tmpc_dim +\dim_new:N \g_tmpa_dim +\dim_new:N \g_tmpb_dim +% \end{macrocode} +% \end{variable} +% \end{variable} +% +% \subsection{Creating and initialising \texttt{skip} variables} +% +% \begin{macro}{\skip_new:N,\skip_new:c} +% Allocation of a new internal registers. +% \begin{macrocode} +%<*initex> +\alloc_new:nnnN { skip } \c_zero \c_max_register_int \tex_skipdef:D +%</initex> +%<*package> +\cs_new_protected_nopar:Npn \skip_new:N #1 + { + \chk_if_free_cs:N #1 + \newskip #1 + } +%</package> +\cs_generate_variant:Nn \skip_new:N { c } +% \end{macrocode} +% \end{macro} +% +% \begin{macro}{\skip_zero:N, \skip_zero:c} +% \begin{macro}{\skip_gzero:N, \skip_gzero:c} +% Reset the register to zero. +% \begin{macrocode} +\cs_new_protected_nopar:Npn \skip_zero:N #1 { #1 \c_zero_skip } +\cs_new_protected_nopar:Npn \skip_gzero:N { \pref_global:D \skip_zero:N } +\cs_generate_variant:Nn \skip_zero:N { c } +\cs_generate_variant:Nn \skip_gzero:N { c } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \subsection{Setting \texttt{skip} variables} +% +% \begin{macro}{\skip_set:Nn, \skip_set:cn} +% \begin{macro}{\skip_gset:Nn, \skip_gset:cn} +% Much the same as for dimensions. +% \begin{macrocode} +\cs_new_protected_nopar:Npn \skip_set:Nn #1#2 + { #1 ~ \etex_glueexpr:D #2 \scan_stop: } +\cs_new_protected_nopar:Npn \skip_gset:Nn { \pref_global:D \skip_set:Nn } +\cs_generate_variant:Nn \skip_set:Nn { c } +\cs_generate_variant:Nn \skip_gset:Nn { c } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \begin{macro} +% {\skip_set_eq:NN,\skip_set_eq:cN, \skip_set_eq:Nc,\skip_set_eq:cc} +% \begin{macro} +% {\skip_gset_eq:NN,\skip_gset_eq:cN, \skip_gset_eq:Nc,\skip_gset_eq:cc} +% All straightforward. +% \begin{macrocode} +\cs_new_protected_nopar:Npn \skip_set_eq:NN #1#2 { #1 = #2 } +\cs_generate_variant:Nn \skip_set_eq:NN { c } +\cs_generate_variant:Nn \skip_set_eq:NN { Nc , cc } +\cs_new_protected_nopar:Npn \skip_gset_eq:NN #1#2 { \pref_global:D #1 = #2 } +\cs_generate_variant:Nn \skip_gset_eq:NN { c } +\cs_generate_variant:Nn \skip_gset_eq:NN { Nc , cc } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \begin{macro}{\skip_add:Nn, \skip_add:cn} +% \begin{macro}{\skip_gadd:Nn, \skip_gadd:cn} +% \begin{macro}{\skip_sub:Nn, \skip_sub:cn} +% \begin{macro}{\skip_gsub:Nn, \skip_gsub:cn} +% Using |by| here deals with the (incorrect) case |\skip123|. +% \begin{macrocode} +\cs_new_protected_nopar:Npn \skip_add:Nn #1#2 + { \tex_advance:D #1 by \etex_glueexpr:D #2 \scan_stop: } +\cs_new_protected_nopar:Npn \skip_gadd:Nn { \pref_global:D \skip_add:Nn } +\cs_generate_variant:Nn \skip_add:Nn { c } +\cs_generate_variant:Nn \skip_gadd:Nn { c } +\cs_new_protected_nopar:Npn \skip_sub:Nn #1#2 + { \tex_advance:D #1 by - \etex_glueexpr:D #2 \scan_stop: } +\cs_new_protected_nopar:Npn \skip_gsub:Nn { \pref_global:D \skip_sub:Nn } +\cs_generate_variant:Nn \skip_sub:Nn { c } +\cs_generate_variant:Nn \skip_gsub:Nn { c } +% \end{macrocode} +% \end{macro} +% \end{macro} +% \end{macro} +% \end{macro} +% +% \subsection{Skip expression conditionals} +% +% \begin{macro}[pTF]{\skip_if_eq:nn} +% Comparing skips means doing two expansions to make strings, and then +% testing them. As a result, only equality is tested. +% \begin{macrocode} +\prg_new_conditional:Npnn \skip_if_eq:nn #1#2 { p , T , F , TF } + { + \if_int_compare:w + \pdftex_strcmp:D { \skip_eval:n { #1 } } { \skip_eval:n { #2 } } + = \c_zero + \prg_return_true: + \else: + \prg_return_false: + \fi: + } +% \end{macrocode} +% \end{macro} +% +% \begin{macro}[pTF]{\skip_if_infinite_glue:n} +% With \eTeX{} we all of a sudden get access to a lot information we +% should otherwise consider ourselves lucky to get. One is +% the stretch and shrink components of a skip register and the order +% or those components. cs{skip_if_infinite_glue:nTF} tests it directly by +% looking at the stretch and shrink order. If either of the predicate +% functions return \meta{true}, |\bool_if:nTF| will return \meta{true} +% and the logic test will take the true branch. +% \begin{macrocode} +\prg_new_conditional:Npnn \skip_if_infinite_glue:n #1 { p , T , F , TF } + { + \bool_if:nTF + { + \int_compare_p:nNn { \etex_gluestretchorder:D #1 } > \c_zero || + \int_compare_p:nNn { \etex_glueshrinkorder:D #1 } > \c_zero + } + { \prg_return_true: } + { \prg_return_false: } + } +% \end{macrocode} +% \end{macro} +% +% \subsection{Using \texttt{skip} expressions and variables} +% +% \begin{macro}{\skip_eval:n} +% Evaluating a skip expression expandably. +% \begin{macrocode} +\cs_new_nopar:Npn \skip_eval:n #1 + { \skip_use:N \etex_glueexpr:D #1 \scan_stop: } +% \end{macrocode} +% \end{macro} +% +% \begin{macro}{\skip_use:N, \skip_use:c} +% Accessing a \meta{skip}. +% \begin{macrocode} +\cs_new_eq:NN \skip_use:N \tex_the:D +\cs_generate_variant:Nn \skip_use:N { c } +% \end{macrocode} +% \end{macro} +% +% \subsection{Inserting skips into the output} +% +% \begin{macro}{\skip_horizontal:N, \skip_horizontal:c, \skip_horizontal:n} +% \begin{macro}{\skip_vertical:N, \skip_vertical:c, \skip_vertical:n} +% Inserting skips. +% \begin{macrocode} +\cs_new_eq:NN \skip_horizontal:N \tex_hskip:D +\cs_new_nopar:Npn \skip_horizontal:n #1 + { \skip_horizontal:N \etex_glueexpr:D #1 \scan_stop: } +\cs_new_eq:NN \skip_vertical:N \tex_vskip:D +\cs_new_nopar:Npn \skip_vertical:n #1 + { \skip_vertical:N \etex_glueexpr:D #1 \scan_stop: } +\cs_generate_variant:Nn \skip_horizontal:N { c } +\cs_generate_variant:Nn \skip_vertical:N { c } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \subsection{Viewing \texttt{skip} variables} +% +% \begin{macro}{\skip_show:N, \skip_show:c} +% Diagnostics. +% \begin{macrocode} +\cs_new_eq:NN \skip_show:N \kernel_register_show:N +\cs_generate_variant:Nn \skip_show:N { c } +% \end{macrocode} +% \end{macro} +% +% \subsection{Constant skips} +% +% \begin{macro}{\c_zero_skip} +% \begin{macro}{\c_max_skip} +% Skips with no rubber component are just dimensions +% \begin{macrocode} +\cs_new_eq:NN \c_zero_skip \c_zero_dim +\cs_new_eq:NN \c_max_skip \c_max_dim +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \subsection{Scratch skips} +% +% \begin{variable}{\l_tmpa_skip, \l_tmpb_skip, \l_tmpc_skip} +% \begin{variable}{\g_tmpa_skip, \g_tmpb_skip} +% We provide three local and two global scratch registers, maybe we +% need more or less. +% \begin{macrocode} +\skip_new:N \l_tmpa_skip +\skip_new:N \l_tmpb_skip +\skip_new:N \l_tmpc_skip +\skip_new:N \g_tmpa_skip +\skip_new:N \g_tmpb_skip +% \end{macrocode} +% \end{variable} +% \end{variable} +% +% \subsection{Creating and initialising \texttt{muskip} variables} +% +% \begin{macro}{\muskip_new:N, \muskip_new:c} +% And then we add muskips. +% \begin{macrocode} +%<*initex> +\alloc_new:nnnN { muskip } \c_zero \c_max_register_int \tex_muskipdef:D +%</initex> +%<*package> +\cs_new_protected_nopar:Npn \muskip_new:N #1 + { + \chk_if_free_cs:N #1 + \newmuskip #1 + } +%</package> +\cs_generate_variant:Nn \muskip_new:N { c } +% \end{macrocode} +% \end{macro} +% +% \begin{macro}{\muskip_zero:N, \muskip_zero:c} +% \begin{macro}{\muskip_gzero:N, \muskip_gzero:c} +% Reset the register to zero. +% \begin{macrocode} +\cs_new_protected_nopar:Npn \muskip_zero:N #1 + { #1 \c_zero_muskip } +\cs_new_protected_nopar:Npn \muskip_gzero:N { \pref_global:D \muskip_zero:N } +\cs_generate_variant:Nn \muskip_zero:N { c } +\cs_generate_variant:Nn \muskip_gzero:N { c } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \subsection{Setting \texttt{muskip} variables} +% +% \begin{macro}{\muskip_set:Nn, \muskip_set:cn} +% \begin{macro}{\muskip_gset:Nn, \muskip_gset:cn} +% This should be pretty familiar. +% \begin{macrocode} +\cs_new_protected_nopar:Npn \muskip_set:Nn #1#2 + { #1 ~ \etex_muexpr:D #2 \scan_stop: } +\cs_new_protected_nopar:Npn \muskip_gset:Nn { \pref_global:D \muskip_set:Nn } +\cs_generate_variant:Nn \muskip_set:Nn { c } +\cs_generate_variant:Nn \muskip_gset:Nn { c } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \begin{macro} +% { +% \muskip_set_eq:NN, \muskip_set_eq:cN, +% \muskip_set_eq:Nc, \muskip_set_eq:cc +% } +% \begin{macro} +% { +% \muskip_gset_eq:NN,\muskip_gset_eq:cN, +% \muskip_gset_eq:Nc,\muskip_gset_eq:cc +% } +% All straightforward. +% \begin{macrocode} +\cs_new_protected_nopar:Npn \muskip_set_eq:NN #1#2 { #1 = #2 } +\cs_generate_variant:Nn \muskip_set_eq:NN { c } +\cs_generate_variant:Nn \muskip_set_eq:NN { Nc , cc } +\cs_new_protected_nopar:Npn \muskip_gset_eq:NN #1#2 { \pref_global:D #1 = #2 } +\cs_generate_variant:Nn \muskip_gset_eq:NN { c } +\cs_generate_variant:Nn \muskip_gset_eq:NN { Nc , cc } +% \end{macrocode} +% \end{macro} +% \end{macro} +% +% \begin{macro}{\muskip_add:Nn, \muskip_add:cn} +% \begin{macro}{\muskip_gadd:Nn, \muskip_gadd:cn} +% \begin{macro}{\muskip_sub:Nn, \muskip_sub:cn} +% \begin{macro}{\muskip_gsub:Nn, \muskip_gsub:cn} +% Using |by| here deals with the (incorrect) case |\muskip123|. +% \begin{macrocode} +\cs_new_protected_nopar:Npn \muskip_add:Nn #1#2 + { \tex_advance:D #1 by \etex_muexpr:D #2 \scan_stop: } +\cs_new_protected_nopar:Npn \muskip_gadd:Nn { \pref_global:D \muskip_add:Nn } +\cs_generate_variant:Nn \muskip_add:Nn { c } +\cs_generate_variant:Nn \muskip_gadd:Nn { c } +\cs_new_protected_nopar:Npn \muskip_sub:Nn #1#2 + { \tex_advance:D #1 by - \etex_muexpr:D #2 \scan_stop: } +\cs_new_protected_nopar:Npn \muskip_gsub:Nn { \pref_global:D \muskip_sub:Nn } +\cs_generate_variant:Nn \muskip_sub:Nn { c } +\cs_generate_variant:Nn \muskip_gsub:Nn { c } +% \end{macrocode} +% \end{macro} +% \end{macro} +% \end{macro} +% \end{macro} +% +% \subsection{Using \texttt{muskip} expressions and variables} +% +% \begin{macro}{\muskip_eval:n} +% Evaluating a muskip expression expandably. +% \begin{macrocode} +\cs_new_nopar:Npn \muskip_eval:n #1 + { \muskip_use:N \etex_muexpr:D #1 \scan_stop: } +% \end{macrocode} +% \end{macro} +% +% \begin{macro}{\muskip_use:N, \muskip_use:c} +% Accessing a \meta{muskip}. +% \begin{macrocode} +\cs_new_eq:NN \muskip_use:N \tex_the:D +\cs_generate_variant:Nn \muskip_use:N { c } +% \end{macrocode} +% \end{macro} +% +% \subsection{Viewing \texttt{muskip} variables} +% +% \begin{macro}{\muskip_show:N, \muskip_show:c} +% Diagnostics. +% \begin{macrocode} +\cs_new_eq:NN \muskip_show:N \kernel_register_show:N +\cs_generate_variant:Nn \muskip_show:N { c } +% \end{macrocode} +% \end{macro} +% +% \subsection{Experimental skip functions} +% +% \begin{macro}{\skip_split_finite_else_action:nnNN} +% This macro is useful when performing error checking in certain +% circumstances. If the \m{skip} register holds finite glue it sets +% |#3| and |#4| to the stretch and shrink component, resp. If it holds +% infinite glue set |#3| and |#4| to zero and issue the special action +% |#2| which is probably an error message. +% Assignments are global. +% \begin{macrocode} +\cs_new_nopar:Npn \skip_split_finite_else_action:nnNN #1#2#3#4 + { + \skip_if_infinite_glue:nTF {#1} + { + #3 = \c_zero_skip + #4 = \c_zero_skip + #2 + } + { + #3 = \etex_gluestretch:D #1 \scan_stop: + #4 = \etex_glueshrink:D #1 \scan_stop: + } + } +% \end{macrocode} +% \end{macro} +% +% \begin{macrocode} +%</initex|package> +% \end{macrocode} +% +% \end{implementation} +% +% \PrintIndex |