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author | Karl Berry <karl@freefriends.org> | 2013-03-12 22:38:22 +0000 |
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committer | Karl Berry <karl@freefriends.org> | 2013-03-12 22:38:22 +0000 |
commit | 574c4946ce553944c797750da25ba8844775996f (patch) | |
tree | 9ea4729ca09c49a4564d99d9134a5417eb7b2af3 /Master/texmf-dist/doc/latex/l3kernel/l3styleguide.tex | |
parent | 5c30ca128a813719715e012a0d72c1ccaba2d811 (diff) |
latex3 (12mar13)
git-svn-id: svn://tug.org/texlive/trunk@29361 c570f23f-e606-0410-a88d-b1316a301751
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diff --git a/Master/texmf-dist/doc/latex/l3kernel/l3styleguide.tex b/Master/texmf-dist/doc/latex/l3kernel/l3styleguide.tex deleted file mode 100644 index 6a3a9d122e6..00000000000 --- a/Master/texmf-dist/doc/latex/l3kernel/l3styleguide.tex +++ /dev/null @@ -1,242 +0,0 @@ -\iffalse meta-comment - -File l3styleguide.tex Copyright (C) 2011,2012 The LaTeX3 Project - -It may be distributed and/or modified under the conditions of the -LaTeX Project Public License (LPPL), either version 1.3c of this -license or (at your option) any later version. The latest version -of this license is in the file - - http://www.latex-project.org/lppl.txt - -This file is part of the "l3kernel bundle" (The Work in LPPL) -and all files in that bundle must be distributed together. - -The released version of this bundle is available from CTAN. - -\fi - -\documentclass{l3doc} -\usepackage{svn-multi} - -\svnid{$Id: l3styleguide.tex 2772 2011-09-07 15:07:41Z joseph $} -\def\filedate{\svnfileyear/\svnfilemonth/\svnfileday} - -\title{% - The \LaTeX3 kernel: style guide for code authors% - \thanks - {% - This file describes v\svnfilerev, - last revised \filedate. - }% -} -\author{% - The \LaTeX3 Project\thanks - {% - E-mail: - \href{mailto:latex-team@latex-project.org}% - {latex-team@latex-project.org}% - }% -} -\date{Released \filedate} - -\begin{document} - -\maketitle - -\tableofcontents - -\section{Introduction} - -This document is intended as a style guide for authors of code and -documentation for the \LaTeX3 kernel. It covers both aspects of coding -style and the formatting of the sources. The aim of providing these -guidelines is help ensure consistency of the code and sources from -different authors. Experience suggests that in the long-term this helps -with maintenance. There will of course be places where there are -exceptions to these guidelines: common sense should always be -applied! - -\section{Documentation style} - -\LaTeX3 source and documentation should be written using the document -class \cls{l3doc} in \file{dtx} format. This class provides a number -of logical mark up elements, which should be used where possible. -In the main, this is standard \LaTeX{} practice, but there are a -few points to highlight: -\begin{itemize} - \item - Where possible, use \cs{cs} to mark up control sequences - rather than using a verbatim environment. - \item - Arguments which are given in braces should be marked using - \cs{Arg} when code-level functions are discussed, but using - \cs{marg} for document functions. - \item - The names \TeX{}, \LaTeX{}, \emph{etc}.\ use the normal logical mark - up followed by an empty group (|{}|), with the exception of |\LaTeX3|, - where the number should follow directly. - \item - Where in line verbatim text is used, it should be marked up - using the \verb=|...|= construct (\emph{i.e.}~vertical bars delimit - the verbatim text). - \item In line quotes should be marked up using the \cs{enquote} - function. - \item - Where numbers in the source have a mathematical meaning, - they should be included in math mode. Such in-line math mode - material should be marked up using |$...$| and \emph{not} - |\(...\)|. -\end{itemize} - -Line length in the source files should to be under $80$ -characters where possible, as this helps keep everything on the screen -when editing files. In the \file{dtx} format, documentation lines start -with a \texttt{\%}, which is usually followed by a space to leave a -\enquote{comment margin} at the start of each line. - -As with code indenting (see later), nested environments and arguments -should be indented by (at least) two spaces to make the nature of the nesting -clear. Thus for example a typical arrangement for the \env{function} -environment might be -\begin{verbatim*} -\begin{function}{\seq_gclear:N, \seq_gclear:c} - \begin{syntax} - \cs{seq_gclear:N} \meta{sequence} - \end{syntax} - Clears all entries from the \meta{sequence} globally. -\end{function} -\end{verbatim*} -The \enquote{outer} \verb*|% \begin{function}| should have the customary -space after the |%| character at the start of the line. - -In general, a single \env{function} or \env{macro} environment should be -used for a group of closely-related functions, for example argument -specification variants. In such cases, a comma-separated list should be -used, as shown in the preceding example. - -\section{Format of the code itself} - -The requirement for less than $80$ characters per line applies to the code -itself as well as the surrounding documentation. A number of the general -style principals for \LaTeX3 code apply: these are described in the following -paragraph and an example is then given. - -With the exception of simple runs of parameter (|{#1}|, |#1#2|, -\emph{etc.}), everything should divided up using spaces to make the code -more readable. In general, these will be single spaces, but in some -places it makes more sense to align parts of the code to emphasise -similarity. (Tabs should not be used for introducing white space.) - -Each conceptually-separate step in a function should be on a separate -line, to make the meaning clearer. Hence the \texttt{false} branch -in the example uses two lines for the two auxiliary function uses. - -Within the definition, a two-space indent should be used to show each -\enquote{level} of code. Thus in the example \cs{tl_if_empty:nTF} is -indented by two spaces, but the two branches are indented by four -spaces. Within the \texttt{false} branch, the need for multiple lines -means that an additional two-space indent should be used to show that -these lines are all part of the brace group. - -The result of these lay-out conventions is code which will in general -look like the example: -\begin{verbatim*} -\cs_new:Npn \module_foo:nn #1#2 - { - \tl_if_empty:nTF {#1} - { \module_foo_aux:n { X #2 } } - { - \module_foo_aux:nn {#1} {#2} - \module_foo_aux:n {#1#2} - } - } -\end{verbatim*} - -\section{Code conventions} - -All code-level functions should be \enquote{long} if they accept any -arguments, even if it seems \enquote{very unlikely} that a \cs{par} token -will be passed. Thus \cs{cs_new_nopar:Npn} and so forth should only be used -to create functions which accept no arguments at all. - -The expandability of each function should be well-defined. Functions which -cannot be fully expanded must be \texttt{protected}. This means that expandable -functions must themselves only contain expandable material. Functions which -use any non-expandable material must be defined using \cs{cs_new_protected:Npn} -or similar. - -When using \cs{cs_generate_variant:Nn}, group related variants together -to make the pattern clearer. A common example is variants of a function -which has an \texttt{N}-type first argument: -\begin{verbatim} - \cs_generate_variant:Nn \foo:Nn { NV , No } - \cs_generate_variant:Nn \foo:Nn { c , cV , co } -\end{verbatim} - -There are cases where omitting braces from \texttt{o}-type arguments -is desirable for performance reasons. This should only be done if the -argument is a single token, thus for example -\begin{verbatim} - \tl_set:No \l_some_tl \l_some_other_tl -\end{verbatim} -remains clear and can be used where appropriate. - -\section{Private and internal functions} - -Private functions (those starting \cs{__}) should not be used between modules. -The only exception is where a \enquote{family} of modules share some -\enquote{internal} methods: this happens most obviously in the kernel itself. -Any internal functions or variables \emph{must} be documented in the same way -as public ones. - -The \pkg{l3docstrip} method should be used for internal functions in a module. -This requires a line -\begin{quote} - \ttfamily - \%<@@=\meta{module}> -\end{quote} -at the start of the source (\texttt{.dtx}) file, with internal functions -then written in the form -\begin{verbatim} - \cs_new_protected:Npn \@@_function:nn #1#2 - ... -\end{verbatim} - -\section{Auxiliary functions} - -In general, the team encourage the use of descriptive names in \LaTeX3 code. -Thus many helper functions will have names which describe briefly what they do, -rather than simply indicating that they are auxiliary to some higher-level -function. However, there are places where one or more \texttt{aux} functions -are required. Where possible, these should be differentiated by signature -\begin{verbatim} - \cs_new_protected:Npn \@@_function:nn #1#2 - { - ... - } - \cs_new_protected:Npn \@@_function_aux:nn #1#2 - { - ... - } - \cs_new_protected:Npn \@@_function_aux:w #1#2 \q_stop - { - ... - } -\end{verbatim} -Where more than one auxiliary shares the same signature, the recommended naming -scheme is \texttt{auxi}, \texttt{auxii} and so on. -\begin{verbatim} - \cs_new_protected:Npn \@@_function_auxi:nn #1#2 - { - ... - } - \cs_new_protected:Npn \@@_function_auxii:nn #1#2 - { - ... - } -\end{verbatim} -The use of \texttt{aux_i}, \texttt{aux_ii}, \emph{etc.}\ is discouraged as this -conflicts with the convention used by \cs{use_i:nn} and related functions. - -\end{document} |