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86f6a31e 1% \begin{meta-comment}
2%
3% $Id: at.dtx,v 1.1 2002/02/03 20:49:02 mdw Exp $
4%
5% Allow @-commands
6%
7% (c) 1995 Mark Wooding
8%
86f6a31e 9% \end{meta-comment}
10%
11% \begin{meta-comment} <general public licence>
12%%
13%% at package -- support for `@' commands'
14%% Copyright (c) 1996 Mark Wooding
15%%
16%% This program is free software; you can redistribute it and/or modify
17%% it under the terms of the GNU General Public License as published by
18%% the Free Software Foundation; either version 2 of the License, or
19%% (at your option) any later version.
20%%
21%% This program is distributed in the hope that it will be useful,
22%% but WITHOUT ANY WARRANTY; without even the implied warranty of
23%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
24%% GNU General Public License for more details.
25%%
26%% You should have received a copy of the GNU General Public License
27%% along with this program; if not, write to the Free Software
28%% Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
29%%
30% \end{meta-comment}
31%
32% \begin{meta-comment} <Package preamble>
33%<+package>\NeedsTeXFormat{LaTeX2e}
34%<+package>\ProvidesPackage{at}
35%<+package> [1996/05/02 1.3 @-command support (MDW)]
36% \end{meta-comment}
37%
38% \CheckSum{355}
39%% \CharacterTable
40%% {Upper-case \A\B\C\D\E\F\G\H\I\J\K\L\M\N\O\P\Q\R\S\T\U\V\W\X\Y\Z
41%% Lower-case \a\b\c\d\e\f\g\h\i\j\k\l\m\n\o\p\q\r\s\t\u\v\w\x\y\z
42%% Digits \0\1\2\3\4\5\6\7\8\9
43%% Exclamation \! Double quote \" Hash (number) \#
44%% Dollar \$ Percent \% Ampersand \&
45%% Acute accent \' Left paren \( Right paren \)
46%% Asterisk \* Plus \+ Comma \,
47%% Minus \- Point \. Solidus \/
48%% Colon \: Semicolon \; Less than \<
49%% Equals \= Greater than \> Question mark \?
50%% Commercial at \@ Left bracket \[ Backslash \\
51%% Right bracket \] Circumflex \^ Underscore \_
52%% Grave accent \` Left brace \{ Vertical bar \|
53%% Right brace \} Tilde \~}
54%%
55%
56% \begin{meta-comment} <driver>
57%
58%<*driver>
59\input{mdwtools}
60\describespackage{at}
61\aton
62\atlet p=\package
63\atdef at{\package{at}}
64\atdef={\mbox{-}}
65\atdef-{@@@=}
66\atlet.=\syntax
67\mdwdoc
68%</driver>
69%
70% \end{meta-comment}
71%
72% \section{User guide}
73%
74% The @at\ package is an attempt to remove a lot of tedious typing that
75% ends up in \LaTeX\ documents, by expanding the number of short command
76% names available. The new command names begin with the `|@|' character,
77% rather than the conventional `|\|', so you can tell them apart.
78%
79% The package provides some general commands for defining @-commands, and
80% then uses them to define some fairly simple ones which will be useful to
81% most people.
82%
83% The rules for @-command names aren't terribly complex:
84% \begin{itemize}
85% \item If the first character of the name is a letter, then the command name
86% consists of all characters up to, but not including, the first
87% nonletter. Spaces following the command name are ignored.
88% \item If the first character of the name is a backslash, then the @-command
89% name consists of the control sequence introduced by the backslash.
90% \item Otherwise, the command name consists only of that first character.
91% Spaces following the name are not ignored, unless that character
92% was itself a space character.
93% \end{itemize}
94%
95% Usually, digits are not considered to be letters. However, the
96% \package{at} package will consider digits to be letters if you give it the
97% \textsf{digits} option in the |\usepackage| command. (Note that this
98% only affects the \package{at} package; it won't change the characters
99% allowed in normal command names.)
100%
101% \DescribeMacro{\atallowdigits}
102% \DescribeMacro{\atdisallowdigits}
103% You can enable and disable digits being considered as letters dynamically.
104% The |\atallowdigits| command allows digits to be used as letters;
105% |\atdisallowdigits| prevents this. Both declarations follow \LaTeX's
106% usual scoping rules. Both of these commands have corresponding
107% environments with the same names (without the leading `|\|', obviously).
108%
109% \subsection{Defining @-commands}
110%
111% \DescribeMacro{\newatcommand}
112% \DescribeMacro{\renewatcommand}
113% The |\newatcommand| command will define a new @-command using a syntax
114% similar to |\newcommand|. For example, you could define
115% \begin{listing}
116%\newatcommand c[1]{\chapter{#1}}
117% \end{listing}
118% to make @.{"@c{"<name>"}"} equivalent to @.{"\\chapter{"<name>"}"}.
119%
120% A |\renewatcommand| is also provided to redefine existing commands, should
121% the need arise.
122%
123% \DescribeMacro{\atdef}
124% For \TeX\ hackers, the |\atdef| command defines @-commands using a syntax
125% similar to \TeX's built-in |\def|.
126%
127% As an example, the following command makes @.{"@/"<text>"/"} write its
128% argument \<text> in italics:
129% \begin{listing}
130%\atdef/#1/{\textit{#1}}
131% \end{listing}
132% The real implementation of the |@/|\dots|/| command is a bit more
133% complex, and is given in the next section.
134%
135% You can use all of \TeX's features for defining the syntax of your
136% command. (See chapter~20 of @/The \TeX book/ for more details.)
137%
138% \DescribeMacro{\atlet}
139% Since |\atdef| is provided to behave similarly to |\def|, @at\ provides
140% |\atlet| which works similarly to |\let|. For example you can say
141% \begin{listing}
142%\atlet!=\index
143% \end{listing}
144% to allow the short |@!| to behave exactly like |\index|.
145%
146% Note that all commands defined using these commands are robust even if you
147% use fragile commands in their definitions. Unless you start doing very
148% strange things, @-commands never need |\protect|ing.
149%
150% \subsection{Predefined @-commands}
151%
152% A small number of hopefully useful commands are provided by default.
153% These are described in the table below:
154%
155% \bigskip \begin{center} \begin{tabular}{lp{3in}} \hline
156% \bf Command & \bf Meaning \\ \hline
157% @.{"@@"} & Typesets an `@@' character. \\
158% @.{"@/"<text>"/"} & In text (LR or paragraph) mode, typesets its
159% argument emphasised. In maths mode, it
160% always chooses italics. \\
161% @.{"@*"<text>"*"} & Typesets its argument \<text> in bold. \\
162% @.{"@i{"<text>"}"} & Equivalent to `@.{"\\index{"<text>"}"}'. \\
163% @.{"@I{"<text>"}"} & As for |@i|, but also writes its argument
164% to the document. \\ \hline
165% \end{tabular} \end{center} \bigskip
166%
167% Package writers should not rely on any predefined @-commands -- they're
168% provided for users, and users should be able to redefine them without
169% fear of messing anything up. (This includes the `standard' commands
170% provided by the @at\ package, by the way. They're provided in the vague
171% hope that they might be useful, and as examples.)
172%
173% \implementation
174%
175% \section{Implementation}
176%
177% \begin{macrocode}
178%<*package>
179% \end{macrocode}
180%
181% \subsection{Options handling}
182%
183% We need a switch to say whether digits should be allowed. Since this
184% is a user thing, I'll avoid |\newif| and just define the thing by hand.
185%
186% \begin{macrocode}
187\def\atallowdigits{\let\ifat@digits\iftrue}
188\def\atdisallowdigits{\let\ifat@digits\iffalse}
189% \end{macrocode}
190%
191% Now define the options.
192%
193% \begin{macrocode}
194\DeclareOption{digits}{\atallowdigits}
195\DeclareOption{nodigits}{\atdisallowdigits}
196\ExecuteOptions{nodigits}
197\ProcessOptions
198% \end{macrocode}
199%
200% \subsection{How the commands work}
201%
202% Obviously we make the `@@' character active. It inspects the next
203% character (or argument, actually -- it can be enclosed in braces for
204% longer commands, although this is a bit futile), and builds the command
205% name from that.
206%
207% The |\at| command is equivalent to the active `@@' character always.
208%
209%
210% \subsection{Converting command names}
211%
212% We need to be able to read an @-command name, and convert it to a normal
213% \TeX\ control sequence. First, we declare some control sequences for
214% braces, which we need later.
215%
216% \begin{macrocode}
217\begingroup
218\catcode`\<1
219\catcode`\>2
220\catcode`\{12
221\catcode`\}12
222\gdef\at@lb<{>
223\gdef\at@rb<}>
224\gdef\at@spc< >
225\endgroup
226% \end{macrocode}
227%
228% I'll set up some helper routines now, to help me read the command
229% names. The way this works is that we |\futurelet| the token into
230% |\@let@token|. These routines will then sort out what to do next.
231%
232% \begin{macro}{\at@test}
233%
234% Given an |\if|\dots\ test, does its first or second argument.
235%
236% \begin{macrocode}
237\def\at@test#1\then{%
238 #1\expandafter\@firstoftwo\else\expandafter\@secondoftwo\fi%
239}
240% \end{macrocode}
241%
242% \end{macro}
243%
244% \begin{macro}{\at@ifcat}
245%
246% Checks the category code of the current character. If it matches the
247% argument, it does its second argument, otherwise it does the third.
248%
249% \begin{macrocode}
250\def\at@ifcat#1{\at@test\ifcat#1\noexpand\@let@token\then}
251% \end{macrocode}
252%
253% \end{macro}
254%
255% \begin{macro}{\at@ifletter}
256%
257% This routine tests the token to see if it's a letter, and if so adds
258% it to the token list and does the first argument; otherwise it does the
259% second argument. It accepts digits as letters if the switch is turned
260% on.
261%
262% There's some fun later, so I'll describe this slowly. First, we compare
263% the category code to a letter, and if we have a match, we know we're done;
264% we need to pick up the letter as an argument. If the catcode is `other',
265% we must compare with numbers to see if it's in range.
266%
267% \begin{macrocode}
268\def\at@ifletter#1#2{%
269 \at@ifcat x%
270 {\at@ifletter@ii{#1}}%
271 {\at@ifcat 0%
272 {\at@ifletter@i{#1}{#2}}%
273 {#2}%
274 }%
275}
276% \end{macrocode}
277%
278% Right. It's `other' (so it's safe to handle as a macro argument) and we
279% need to know if it's a digit. This is a little tricky: I use |\if| to
280% compare two characters. The first character is~`1' or~`0' depending on the
281% `digit' switch; the second is~`1' or~`x' depending on whether it's actually
282% a digit. They'll only match if everything's worked out OK.
283%
284% \begin{macrocode}
285\def\at@ifletter@i#1#2#3{%
286 \at@test\if%
287 \ifat@digits1\else0\fi%
288 \ifnum`#3<`0x\else\ifnum`#3>`9x\else1\fi\fi%
289 \then%
290 {\at@ifletter@ii{#1}{#3}}%
291 {#2#3}%
292}
293% \end{macrocode}
294%
295% Right; we have the character, so add it to the list and carry on.
296%
297% \begin{macrocode}
298\def\at@ifletter@ii#1#2{\toks@\expandafter{\the\toks@#2}#1}
299% \end{macrocode}
300%
301% \end{macro}
302%
303% Now we define the command name reading routines. We have @/almost/ the
304% same behaviour as \TeX, although we can't support `|%|' characters for
305% reasons to do with \TeX's tokenising algorithm.
306%
307% \begin{macro}{\at@read@name}
308%
309% The routine which actually reads the command name works as follows:
310% \begin{enumerate}
311% \item Have a peek at the next character. If it's a left or right brace,
312% then use the appropriate character.
313% \item If the character is not a letter, just use the character (or whole
314% control sequence.
315% \item Finally, if it's a letter, keep reading letters until we find one
316% that wasn't.
317% \end{enumerate}
318%
319% First, we do some setting up and read the first character
320%
321% \begin{macrocode}
322\def\at@read@name#1{%
323 \let\at@next=#1%
324 \toks@{}%
325 \futurelet\@let@token\at@rn@i%
326}
327% \end{macrocode}
328%
329% Next, sort out what to do, based on the category code.
330%
331% \begin{macrocode}
332\def\at@rn@i{%
333 \def\@tempa{\afterassignment\at@rn@iv\let\@let@token= }%
334 \at@ifletter%
335 {\futurelet\@let@token\at@rn@iii}%
336 {\at@ifcat\bgroup%
337 {\toks@\expandafter{\at@lb}\@tempa}%
338 {\at@ifcat\egroup%
339 {\toks@\expandafter{\at@rb}\@tempa}%
340 {\at@ifcat\at@spc%
341 {\toks@{ }\@tempa}%
342 {\at@rn@ii}%
343 }%
344 }%
345 }%
346}
347% \end{macrocode}
348%
349% Most types of tokens can be fiddled using |\string|.
350%
351% \begin{macrocode}
352\def\at@rn@ii#1{%
353 \toks@\expandafter{\string#1}%
354 \at@rn@iv%
355}
356% \end{macrocode}
357%
358% We've found a letter, so we should check for another one.
359%
360% \begin{macrocode}
361\def\at@rn@iii{%
362 \at@ifletter%
363 {\futurelet\@let@token\at@rn@iii}%
364 {\@ifnextchar.\at@rn@iv\at@rn@iv}%
365}
366% \end{macrocode}
367%
368% Finally, we need to pass the real string, as an argument, to the
369% macro. We make |\@let@token| relax, since it might be something which will
370% upset \TeX\ later, e.g., a |#| character.
371%
372% \begin{macrocode}
373\def\at@rn@iv{%
374 \let\@let@token\relax%
375 \expandafter\at@next\csname at.\the\toks@\endcsname%
376}
377% \end{macrocode}
378%
379% \end{macro}
380%
381% \begin{macro}{\at@cmdname}
382%
383% Given a control sequence, work out which @-command it came from.
384%
385% \begin{macrocode}
386\def\at@cmdname#1{\expandafter\at@cmdname@i\string#1\@@foo}
387% \end{macrocode}
388%
389% Now extract the trailing bits.
390%
391% \begin{macrocode}
392\def\at@cmdname@i#1.#2\@@foo{#2}
393% \end{macrocode}
394%
395% \end{macro}
396%
397% \begin{macro}{\at@decode}
398%
399% The |\at@decode| macro takes an extracted @-command name, and tries to
400% execute the correct control sequence derived from it.
401%
402% \begin{macrocode}
403\def\at@decode#1{%
404 \at@test\ifx#1\relax\then{%
405 \PackageError{at}{Unknown @-command `@\at@cmdname#1'}{%
406 The @-command you typed wasn't recognised, so I've ignored it.
407 }%
408 }{%
409 #1%
410 }%
411}
412% \end{macrocode}
413%
414% \end{macro}
415%
416% \begin{macro}{\@at}
417%
418% We'd like a measure of compatibility with @p{amsmath}. The @-commands
419% provided by @p{amsmath} work only in maths mode, so this gives us a way of
420% distinguishing. If the control sequence |\Iat| is defined, and we're in
421% maths mode, we'll call that instead of doing our own thing.
422%
423% \begin{macrocode}
424\def\@at{%
425 \def\@tempa{\at@read@name\at@decode}%
426 \ifmmode\ifx\Iat\not@@defined\else%
427 \let\@tempa\Iat%
428 \fi\fi%
429 \@tempa%
430}
431% \end{macrocode}
432%
433% \end{macro}
434%
435%
436% \subsection{Defining new commands}
437%
438% \begin{macro}{\at@buildcmd}
439%
440% First, we define a command to build these other commands:
441%
442% \begin{macrocode}
443\def\at@buildcmd#1#2{%
444 \expandafter\def\csname\expandafter
445 \@gobble\string#1@decode\endcsname##1{#2##1}%
446 \edef#1{%
447 \noexpand\at@read@name%
448 \expandafter\noexpand%
449 \csname\expandafter\@gobble\string#1@decode\endcsname%
450 }%
451}
452% \end{macrocode}
453%
454% \end{macro}
455%
456% \begin{macro}{\newatcommand}
457% \begin{macro}{\renewatcommand}
458% \begin{macro}{\provideatcommand}
459% \begin{macro}{\atdef}
460% \begin{macro}{\atshow}
461%
462% Now we define the various operations on @-commands.
463%
464% \begin{macrocode}
465\at@buildcmd\newatcommand\newcommand
466\at@buildcmd\renewatcommand\renewcommand
467\at@buildcmd\provideatcommand\providecommand
468\at@buildcmd\atdef\def
469\at@buildcmd\atshow\show
470% \end{macrocode}
471%
472% \end{macro}
473% \end{macro}
474% \end{macro}
475% \end{macro}
476% \end{macro}
477%
478% \begin{macro}{\atlet}
479%
480% |\atlet| is rather harder than the others, because we want to allow people
481% to say things like @.{"\\atlet"<name>"=@"<name>}. The following hacking
482% does the trick. I'm trying very hard to duplicate |\let|'s behaviour with
483% respect to space tokens here, to avoid any surprises, although there
484% probably will be some differences. In particular, |\afterassignment|
485% won't work in any sensible way.
486%
487% First, we read the name of the @-command we're defining. We also open
488% a group, to stop messing other people up, and make `@@' into an `other'
489% token, so that it doesn't irritatingly look like its meaning as a control
490% sequence.
491%
492% \begin{macrocode}
493\def\atlet{%
494 \begingroup%
495 \@makeother\@%
496 \at@read@name\atlet@i%
497}
498% \end{macrocode}
499%
500% Put the name into a scratch macro for later use. Now see if there's an
501% equals sign up ahead. If not, this will gobble any spaces in between the
502% @-command name and the argument.
503%
504% \begin{macrocode}
505\def\atlet@i#1{%
506 \def\at@temp{#1}%
507 \@ifnextchar=\atlet@ii{\atlet@ii=}%
508}
509% \end{macrocode}
510%
511% Now we gobble the equals sign (whatever catcode it is), and peek at the
512% next token up ahead using |\let| with no following space.
513%
514% \begin{macrocode}
515\def\atlet@ii#1{\afterassignment\atlet@iii\global\let\at@gnext=}
516% \end{macrocode}
517%
518% The control sequence |\at@gnext| is now |\let| to be whatever we want the
519% @-command to be, unless it's picked up an `@@' sign. If it has, we've
520% eaten the |@| token, so just read the name and pass it on. Otherwise,
521% we can |\let| the @-command directly to |\at@gnext|. There's some
522% nastiness here to make |\the\toks@| expand before we close the group and
523% restore its previous definition.
524%
525% \begin{macrocode}
526\def\atlet@iii{%
527 \if @\noexpand\at@gnext%
528 \expandafter\at@read@name\expandafter\atlet@iv%
529 \else%
530 \expandafter\endgroup%
531 \expandafter\let\at@temp= \at@gnext%
532 \fi%
533}
534% \end{macrocode}
535%
536% We've read the source @-command name, so just copy the definitions over.
537%
538% \begin{macrocode}
539\def\atlet@iv#1{%
540 \expandafter\endgroup%
541 \expandafter\let\at@temp=#1%
542}
543% \end{macrocode}
544%
545% \end{macro}
546%
547%
548% \subsection{Robustness of @-commands}
549%
550% We want all @-commands to be robust. We could leave them all being
551% fragile, although making robust @-commands would then be almost impossible.
552% There are two problems which we must face:
553%
554% \begin{itemize}
555%
556% \item The `|\@at|' command which scans the @-command name is (very)
557% fragile. I could have used |\DeclareRobustCommand| for it (and in
558% fact I did in an earlier version), but that doesn't help the other
559% problem at all.
560%
561% \item The `name' of the @-command may contain active characters or control
562% sequences, which will be expanded at the wrong time unless we do
563% something about it now.
564%
565% \end{itemize}
566%
567% We must also be careful not to introduce extra space characters into any
568% files written, because spaces are significant in @-commands. Finally,
569% we have a minor problem in that most auxiliary files are read in with
570% the `@@' character set to be a letter.
571%
572% \begin{macro}{\at}
573%
574% Following the example of \LaTeX's `short' command handling, we'll define
575% |\at| to decide what to do depending on what |\protect| looks like. If
576% we're typesetting, we just call |\@at| (above) and expect it to cope.
577% Otherwise we call |\at@protect|, which scoops up the |\fi| and the |\@at|,
578% and inserts other magic.
579%
580% \begin{macrocode}
581\def\at{\ifx\protect\@typeset@protect\else\at@protect\fi\@at}
582% \end{macrocode}
583%
584% \end{macro}
585%
586% \begin{macro}{\at@protect}
587%
588% Since we gobbled the |\fi| from the above, we must put that back. We then
589% need to do things which are more complicated. If |\protect| is behaving
590% like |\string|, then we do one sort of protection. Otherwise, we assume
591% that |\protect| is being like |\noexpand|.
592%
593% \begin{macrocode}
594\def\at@protect\fi#1{%
595 \fi%
596 \ifx\protect\string%
597 \expandafter\at@protect@string%
598 \else%
599 \expandafter\at@protect@noexpand%
600 \fi%
601}
602% \end{macrocode}
603%
604% \end{macro}
605%
606% \begin{macro}{\at@protect@string}
607%
608% When |\protect| is |\string|, we don't need to be able to recover the
609% original text particularly accurately -- it's for the user to look at.
610% Therefore, we just output a $|@|_{11}$ and use |\string| on the next
611% token. This must be sufficient, since we only allow multi-token command
612% names if the first token is a letter (code~11).
613%
614% \begin{macrocode}
615\def\at@protect@string{@\string}
616% \end{macrocode}
617%
618% \end{macro}
619%
620% \begin{macro}{\at@protect@noexpand}
621%
622% This is a little more complex, since we're still expecting to be executed
623% properly at some stage. However, there's a cheeky dodge we can employ
624% since the |\at| command is thoroughly robustified (or at least it will be
625% by the time we've finished this). All |\@unexpandable@protect| does
626% is confer repeated robustness on a fragile command. Since our command
627% is robust, we don't need this and we can get away with just using a
628% single |\noexpand|, both for the |\@at@| command and the following token
629% (which we must robustify, because no-one else can do it for us -- if
630% anyone tries, they end up using the |@\protect| command which is rather
631% embarassing).
632%
633% I'll give the definition, and then examine how this expands in various
634% cases.
635%
636% \begin{macrocode}
637\def\at@protect@noexpand{\noexpand\@at@ @\noexpand}
638\def\@at@#1{\at}
639% \end{macrocode}
640%
641% A few points, before we go into the main examination of the protection.
642% I've inserted a $|@|_{11}$ token, which is gobbled by |\@at@| when the
643% thing is finally expanded fully. This prevents following space tokens
644% in an |\input| file from being swallowed because they follow a control
645% sequence. (I can't use the normal $|@|_{13}$ token, because when files
646% like the |.aux| file are read in, |@| is given code~11 by
647% |\makeatletter|.)
648%
649% \setbox0\hbox{|@at@|}
650% Now for a description of why this works. When |\at| is expanded, it works
651% out that |\protect| is either |\noexpand| or |\@unexpandable@protect|, and
652% becomes |\at@protect@noexpand|. Because of the |\noexpand| tokens, this
653% stops being expanded once it reaches $\fbox{\box0}\,|@|_{11}\,x$ (where
654% $x$ is the token immediately following the $|@|_{13}$ character). If this
655% is expanded again, for example in another |\edef|, or in a |\write| or a
656% |\mark|, the |\@at@| wakes up, gobbles the following |@| (whatever catcode
657% it is -- there may be intervening |\write| and |\input| commands) and
658% becomes |\at|, and the whole thing can start over again.
659%
660% \end{macro}
661%
662%
663% \subsection{Enabling and disabling @-commands}
664%
665% \begin{macro}{\aton}
666%
667% We define the |\aton| command to enable all of our magic. We store
668% the old catcode in the |\atoff| command, make `@@' active, and make it
669% do the stuff.
670%
671% \begin{macrocode}
672\def\aton{%
673 \ifnum\catcode`\@=\active\else%
674 \edef\atoff{\catcode`\noexpand\@\the\catcode`\@}%
675 \catcode`\@\active%
676 \lccode`\~`\@%
677 \lowercase{\let~\at}%
678 \fi%
679}
680% \end{macrocode}
681%
682% \end{macro}
683%
684% \begin{macro}{\atoff}
685%
686% The |\atoff| command makes `@@' do the stuff it's meant to. We remember
687% the old catcode and revert to it. This is largely unnecessary.
688%
689% \begin{macrocode}
690\def\atoff{\catcode`\@12}
691% \end{macrocode}
692%
693% \end{macro}
694%
695% \begin{macro}{\makeatother}
696%
697% Now we make our active `@@' the default outside of package files.
698%
699% \begin{macrocode}
700\let\makeatother\aton
701% \end{macrocode}
702%
703% \end{macro}
704%
705% And we must make sure that the user can use all of our nice commands.
706% Once the document starts, we allow @-commands.
707%
708% \begin{macrocode}
709\AtBeginDocument{\aton}
710% \end{macrocode}
711%
712% \begin{macro}{\dospecials}
713% \begin{macro}{\@sanitize}
714%
715% We must add the `@@' character to the various specials lists.
716%
717% \begin{macrocode}
718\expandafter\def\expandafter\dospecials\expandafter{\dospecials\do\@}
719\expandafter\def\expandafter\@sanitize\expandafter{%
720 \@sanitize\@makeother\@}
721% \end{macrocode}
722%
723% \end{macro}
724% \end{macro}
725%
726% \subsection{Default @-commands}
727%
728% We define some trivial examples to get the user going.
729%
730% \begin{macrocode}
731\expandafter\chardef\csname at.@\endcsname=`\@
732\atdef*#1*{\ifmmode\mathbf{#1}\else\textbf{#1}\fi}
733\atdef/#1/{\ifmmode\mathit{#1}\else\emph{#1}\fi}
734\atlet i=\index
735\atdef I#1{#1\index{#1}}
736%</package>
737% \end{macrocode}
738%
739% \hfill Mark Wooding, \today
740%
741% \Finale
742%
743\endinput