summaryrefslogtreecommitdiff
path: root/Master/texmf-dist/doc/latex/xoptarg/xoptarg.tex
blob: 38111b7c8641e03bff5040938c6d2572b1af2a4d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
\documentclass{article}

\usepackage{etex}
\usepackage{xifthen}
\usepackage[ascii]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[warn]{textcomp}
\usepackage[a4paper, pdftex, margin=1.5in]{geometry}
\usepackage{lmodern}
\usepackage{typetex}
\usepackage{xoptarg}
\usepackage{microtype}
\usepackage{xcolor}
\usepackage{url}
\usepackage[bottom,hang]{footmisc}
\usepackage[babel]{csquotes}
\usepackage[british]{babel}
\usepackage{hyperref}

\setcounter{secnumdepth}{-\maxdimen}

\newcommand*{\pack}{\textsf}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\newenvironment*{display}{%
  \list{}{}%
  \item \relax
}{%
  \endlist
}

\newcommand*{\setdate}{}
\def \setdate #1/#2/#3#4{%
  \year  = #1
  \month = #2
  \day   = #3#4
}

\makeatletter
\newcommand*{\getfileinfo}[1]{%
  \def \filename {#1}%
  \def \@tempb ##1 ##2 ##3\relax ##4\relax {%
    \def \filedate    {##1}%
    \def \fileversion {##2}%
    \def \fileinfo    {##3}%
  }%
  \edef \@tempa {\csname ver@#1\endcsname}%
  \expandafter \@tempb \@tempa \relax ? ? \relax \relax
}

\newcommand*{\TypeOut}[1]{%
  \texttt{%
    \frenchspacing
    \begingroup
      \let \protect = \string
      \xdef \@gtempa {#1}%
    \endgroup
    \let \@tempa = \@gtempa
    \@onelevel@sanitize \@tempa \@tempa}%
}
\makeatother

\title  {The \pack{xoptarg} Package}
\author {Josselin Noirel\\\url{http://www.jnoirel.fr/}}
\date   {%
  \getfileinfo{xoptarg.sty}
  \expandafter \setdate \filedate
  \today\ (\fileversion)}

\begin{document}

\maketitle

\begin{abstract}
  Because they rely on the \cmd{futurelet} primitive, the macros with
  optional arguments cannot be expandable.  However, it is possible to
  make them expandable if there is at least one mandatory argument
  (see `Limitations').
\end{abstract}

\tableofcontents

\section{Introduction}

\newcommand*{\cmda}[1]{1. #1 2. #1 3. #1 4. #1}
\newcommand*{\cmdb}[3]{[#1#2#3 #1#3#2 #2#1#3 #2#3#1 #3#1#2 #3#2#1]}
\newcommand*{\cmdc}[2][X]{(#1,#2)}

Normal macros are expandable:
%
\begin{texcode}
\cmd[3]{newcommand}*{\cmd{cmda}}[1]{1. \#1 2. \#1 3. \#1 4. \#1} \newline
\cmd[3]{newcommand}*{\cmd{cmdb}}[3]{[\#1\#2\#3 \#1\#3\#2 \#2\#1\#3
  \#2\#3\#1 \#3\#1\#2 \#3\#2\#1]} \newline
\end{texcode}
%
`Expandable' means that if you print them on the terminal with
\cmd{typeout}
%
\begin{texcode}
\cmd[1]{typeout}{\cmd[1]{cmda}{Test}...and \cmd[3]{cmdb}{T}{h}{e} rest} \par
\end{texcode}
%
it will result in the processed message which is printed during the
compilation:
%
\begin{display}
\TypeOut{\cmda{Test}...and \cmdb{T}{h}{e} rest}
\typeout{TEST>>> \cmda{Test}...and \cmdb{T}{h}{e} rest}
\end{display}

But, commands defined to take an optional argument behave
differently.  The code:
%
\begin{texcode}
\cmd[3]{newcommand}*{\cmd{cmdc}}[2][X]{(\#1,\#2)} \newline
\cmd[1]{typeout}{\cmd[2]{cmdc}[A]{B} \cmd[1]{cmdc}{C}}
\end{texcode}
%
prints the unprocessed
%
\begin{display}
\TypeOut{\cmdc[A]{B} \cmdc{C}}
\typeout{TEST>>> \cmdc[A]{B} \cmdc{C}}
\end{display}
%
and not \tex{(A,B)~(X,C)}!  (Of course, in typesetting context, it
doesn't make any difference\dots\ the interest of the package lies
in the expandability in moving-argument contexts.)  The \pack{xoptarg}
helps you to make your macros expandable even when they take an
optional argumen (see `Limitations' though).

\section{Usage}

\subsection{Defining commands}

Your macros, including those that take an optional argument can be
expandable provided they also take at least one mandatory
argument\footnote{If your macros don't take any optional argument, the
  standard behaviour prevails so that you don't to have to worry about
  them.  The `at least one mandatory argument' condition applies only
  when the macro takes an optional argument.}.  Practically spoken,
your command, when it takes an optional argument, must take at least
two arguments in total\footnote{A~second requirement is that the
  mandatory arguments be surrounded by explicit braces \tex{\{\dots\}}.}.

Load the package with
%
\begin{texcode}
\cmd[1]{usepackage}{xoptarg}
\end{texcode}
%
then, instead of using \cmd{newcommand}, use \cmd{xnewcommand}
%
\begin{texcode}
\cmd[4]{xnewcommand}*{\<command\>}[$n$][\<default\>]{\<definition\>}
\end{texcode}
%
This is the same syntax as \cmd{newcommand}'s and it works even if the
command does take any optional argument.  A~normal, non-expandable,
macro is defined when you define a~macro that takes one optional argument
and no mandatory one.  A~warning is issued to inform you that it won't
be possible to make it expandable\footnote{The command will be made
  robust using \cmd{protected} if \eTeX\ is available.}.

\subsection{Changing the prefix}

This package uses \pack{newcommand} that allows a~more sophisticated
syntax:
%
\begin{texcode}
\cmd[5]{xnewcommand}[\<prefix\>]{\<command\>}[$n$][\<default\>]{\<definition\>}
\end{texcode}
%
For instance, to define a~macro globally, use
%
\begin{texcode}
\cmd[3]{xnewcommand}[\cmd{global}]{\<command\>}{\<definition\>}
\end{texcode}
%
(But \cmd{newcommand} would do the job as well, as \pack{newcommand}
improves it also.)

\section{Limitations}

The limitations of the package are the following:
%
\begin{itemize}
\item To be expandable, the macros with an optional argument must have
      at least one mandatory argument.

\item The mandatory arguments must be surrounded by braces in this
      case.

\item There is no \cmd{rexnewcommand} command.
\end{itemize}

\end{document}