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1 | % \begin{meta-comment} |
2 | % |
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3 | % $Id: mdwlist.dtx,v 1.2 2003/09/05 16:13:44 mdw Exp $ |
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4 | % |
5 | % Various list-related things |
6 | % |
7 | % (c) 1996 Mark Wooding |
8 | % |
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9 | % \end{meta-comment} |
10 | % |
11 | % \begin{meta-comment} <general public licence> |
12 | %% |
13 | %% mdwlist package -- various list-related things |
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 preambles> |
33 | %<+package>\NeedsTeXFormat{LaTeX2e} |
34 | %<+package>\ProvidesPackage{mdwlist} |
35 | %<+package> [1996/05/02 1.1 Various list-related things] |
36 | % \end{meta-comment} |
37 | % |
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38 | % \CheckSum{183} |
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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} |
57 | % |
58 | %<*driver> |
59 | \input{mdwtools} |
60 | \describespackage{mdwlist} |
61 | \def\defaultdesc{% |
62 | \desclabelwidth{80pt}% |
63 | \desclabelstyle\nextlinelabel% |
64 | \def\makelabel{\bfseries}% |
65 | } |
66 | \newenvironment{cmdlist} |
67 | {\basedescript{\let\makelabel\cmd}} |
68 | {\endbasedescript} |
69 | \mdwdoc |
70 | %</driver> |
71 | % |
72 | % \end{meta-comment} |
73 | % |
74 | % \section{User guide} |
75 | % |
76 | % This package provides some vaguely useful list-related commands and |
77 | % environments: |
78 | % \begin{itemize*} |
79 | % \item A way of building \env{description}-like environments. |
80 | % \item Commands for making `compacted' versions of list environments |
81 | % \item A method for suspending and resuming enumerated lists. |
82 | % \end{itemize*} |
83 | % |
84 | % \subsection{Description list handling} |
85 | % |
86 | % Different sorts of description-type lists require different sorts of |
87 | % formatting: I think that's fairly obvious. There are essentially three |
88 | % different attributes which should be changable: |
89 | % \begin{itemize*} |
90 | % \item the indentation of the items being described, |
91 | % \item the handling of labels which don't fit properly, and |
92 | % \item the style used to typeset the label text. |
93 | % \end{itemize*} |
94 | % The first two items should usually be decided for all description-like |
95 | % lists in the document, to ensure consistency of appearance. The last |
96 | % depends much more on the content of the labels. |
97 | % |
98 | % \DescribeEnv{basedescript} |
99 | % The \env{basedescript} environment acts as a `skeleton' for description |
100 | % environments. It takes one argument, which contains declarations to |
101 | % be performed while constructing the list. I'd consider it unusual for |
102 | % the \env{basedescript} environment to be used in the main text: it's |
103 | % intended to be used to build other environments. |
104 | % |
105 | % The declarations which can be used to define description-type environments |
106 | % include all of those which are allowed when setting up a list (see the |
107 | % \LaTeX\ book for information here). Some others, which apply specifically |
108 | % to description lists, are also provided: |
109 | % |
110 | % \begin{itemize} |
111 | % |
112 | % \item \DescribeMacro{\desclabelwidth} |
113 | % The \syntax{"\\desclabelwidth{"<length>"}"} declaration sets labels |
114 | % to be left-aligned, with a standard width of \<length>; the item |
115 | % text is indented by \<length> plus the value of |\labelsep|. |
116 | % |
117 | % \item \DescribeMacro{\desclabelstyle} |
118 | % The label style determines how overlong labels are typeset. A style |
119 | % may be set using the \syntax{"\\desclabelstyle{"<style>"}"} |
120 | % declaration. The following \<style>s are provided: |
121 | % \begin{cmdlist} |
122 | % \item [\nextlinelabel] If the label is too wide to fit next to the |
123 | % first line of text, then it is placed on a line by itself; |
124 | % the main text is started on the next line with the usual |
125 | % indentation. |
126 | % \item [\multilinelabel] The label is typeset in a parbox with the |
127 | % appropriate width; if it won't fit on one line, then the |
128 | % text will be split onto subsequent lines. |
129 | % \item [\pushlabel] If the label is too wide to fit in the space |
130 | % allocated to it, the start of the item's text will be `pushed' |
131 | % over to the right to provide space for the label. This is |
132 | % the standard \LaTeX\ \env{description} behaviour. |
133 | % \end{cmdlist} |
134 | % |
135 | % \item \DescribeMacro{\makelabel} |
136 | % The |\makelabel| command is responsible for typesetting a label. |
137 | % It is given one argument, which is the text given as an argument |
138 | % to the |\item| command; it should typeset it appropriately. The |
139 | % text will then be arranged appropriately according to the chosen |
140 | % label style. This command should be redefined using |\renewcommand|. |
141 | % |
142 | % \end{itemize} |
143 | % |
144 | % \begin{figure} |
145 | % \begin{demo}[w]{Various labelling styles} |
146 | %\begin{basedescript}{\desclabelstyle{\nextlinelabel}} |
147 | %\item [Short label] This is a short item, although it has quite a |
148 | % lot of text attached to it. |
149 | %\item [Slightly longer label text] This is a rather longer piece |
150 | % of text, with a correspondingly slightly longer label. |
151 | %\end{basedescript} |
152 | %\medskip |
153 | %\begin{basedescript}{\desclabelstyle{\multilinelabel}} |
154 | %\item [Short label] This is a short item, although it has quite a |
155 | % lot of text attached to it. |
156 | %\item [Slightly longer label text] This is a rather longer piece |
157 | % of text, with a correspondingly slightly longer label. |
158 | %\end{basedescript} |
159 | %\medskip |
160 | %\begin{basedescript}{\desclabelstyle{\pushlabel}} |
161 | %\item [Short label] This is a short item, although it has quite a |
162 | % lot of text attached to it. |
163 | %\item [Slightly longer label text] This is a rather longer piece |
164 | % of text, with a correspondingly slightly longer label. |
165 | %\end{basedescript} |
166 | % \end{demo} |
167 | % \end{figure} |
168 | % |
169 | % \DescribeMacro{\defaultdesc} |
170 | % To allow document designers to control the global appearance of description |
171 | % lists, the |\defaultdesc| command may be redefined; it is called while |
172 | % setting up a new \env{basedescript} list, before performing the user's |
173 | % declarations. By default, it attempts to emulate the standard \LaTeX\ |
174 | % \env{description} environment:\footnote{^^A |
175 | % This is a slightly sanitised version of the real definition, which is |
176 | % given in the implementation section of this document.} |
177 | % \begin{listing} |
178 | %\providecommand{\defaultdesc}{% |
179 | % \desclabelstyle{\pushlabel}% |
180 | % \renewcommand{\makelabel}[1]{\bfseries##1}% |
181 | % \setlength{\labelwidth}{0pt}% |
182 | %} |
183 | % \end{listing} |
184 | % Unfortunately, \LaTeX\ doesn't provide a means for overriding a command |
185 | % which may or may not have been defined yet; in this case, I'd probably |
186 | % recommend using the \TeX\ primitive |\def| to redefine |\defaultdesc|. |
187 | % |
188 | % If you want to redefine the \env{description} environment in terms of |
189 | % the commands in this package, the following method is recommended: |
190 | % \begin{listing} |
191 | %\renewenvironment{description}{% |
192 | % \begin{basedescript}{% |
193 | % \renewcommand{\makelabel}[1]{\bfseries##1}% |
194 | % }% |
195 | %}{% |
196 | % \end{basedescript}% |
197 | %} |
198 | % \end{listing} |
199 | % This ensures that labels are typeset in bold, as is usual, but other |
200 | % properties of the list are determined by the overall document style. |
201 | % |
202 | % \subsection{Compacted lists} |
203 | % |
204 | % \LaTeX\ tends to leave a certain amount of vertical space between list |
205 | % items. While this is normally correct for lists in which the items are |
206 | % several lines long, it tends to look odd if all or almost all the items |
207 | % are only one line long. |
208 | % |
209 | % \DescribeMacro{\makecompactlist} |
210 | % The command |
211 | % \syntax{"\\makecompactlist{"<new-env-name>"}{"<old-env-name>"}"} |
212 | % defines a new environment \<new-env-name> to be a `compacted' version of |
213 | % the existing environment \<old-env-name>; i.e., the two environments are |
214 | % the same except that the compacted version leaves no space between items |
215 | % or paragraphs within the list. |
216 | % |
217 | % \DescribeEnv{itemize*} |
218 | % \DescribeEnv{enumerate*} |
219 | % \DescribeEnv{description*} |
220 | % So that the most common cases are already handled, the package creates |
221 | % compacted $*$-variants of the \env{itemize}, \env{enumerate} and |
222 | % \env{description} environments. These were created using the commands |
223 | % \begin{listing} |
224 | %\makecompactlist{itemize*}{itemize} |
225 | %\makecompactlist{enumerate*}{enumerate} |
226 | %\makecompactlist{description*}{description} |
227 | % \end{listing} |
228 | % |
229 | % Some list environments accept arguments. You can pass an argument to a |
230 | % list environment using an optional argument to its compact variant. For |
231 | % example, |
232 | % \begin{listing} |
233 | %\begin{foolist*}[{someargument}] |
234 | % \end{listing} |
235 | % |
236 | % \subsection{Suspending and resuming list environments} |
237 | % |
238 | % \DescribeMacro{\suspend} |
239 | % \DescribeMacro{\resume} |
240 | % The |\suspend| and |\resume| commands allow you to temporarily end a list |
241 | % environment and then pick it up where you left off. The syntax is fairly |
242 | % simple: |
243 | % |
244 | % \begin{grammar} |
245 | % |
246 | % <suspend-cmd> ::= \[[ |
247 | % "\\suspend" |
248 | % \begin{stack} \\ "[" <name> "]" \end{stack} "{" <env-name> "}" |
249 | % \]]% |
250 | % |
251 | % <resume-cmd> ::= \[[ |
252 | % "\\resume" |
253 | % \begin{stack} \\ "[" <name> "]" \end{stack} "{" <env-name> "}" |
254 | % \begin{stack} \\ "[" <text> "]" \end{stack} |
255 | % \]]% |
256 | % |
257 | % \end{grammar} |
258 | % |
259 | % The \<env-name> is the name of the environment; this will more often than |
260 | % not be the \env{enumerate} environment. The \<name> is a magic name you |
261 | % can use to identify the suspended environment; if you don't specify this, |
262 | % the environment name is used instead. |
263 | % |
264 | % \begin{demo}{Suspended environments} |
265 | %Here's some initial text. It's |
266 | %not very interesting. |
267 | %\begin{enumerate*} |
268 | %\item This is an item. |
269 | %\item This is another. |
270 | %\suspend{enumerate*} |
271 | %Some more commentry text. |
272 | %\resume{enumerate*} |
273 | %\item Another item. |
274 | %\end{enumerate*} |
275 | % \end{demo} |
276 | % |
277 | % You can pass arguments to a resumed list environment through the second |
278 | % optional argument of the |\resume| command. If, for example, you're using |
279 | % David Carlisle's \package{enumerate} package, you could say something like |
280 | % \begin{listing} |
281 | %\begin{enumerate}[\bfseries{Item} i] |
282 | %\item An item |
283 | %\item Another item |
284 | %\suspend{enumerate} |
285 | %Some intervening text. |
286 | %\resume{enumerate}[{[\bfseries{Item} i]}] |
287 | %\item Yet another item |
288 | %\end{enumerate} |
289 | % \end{listing} |
290 | % |
291 | % \implementation |
292 | % |
293 | % \section{Implementation} |
294 | % |
295 | % \begin{macrocode} |
296 | %<*package> |
297 | % \end{macrocode} |
298 | % |
299 | % \subsection{Description lists} |
300 | % |
301 | % \subsubsection{Label styles} |
302 | % |
303 | % \begin{macro}{\nextlinelabel} |
304 | % |
305 | % The idea here is that if the label is too long to fit in its box, we put |
306 | % it on its own line and start the text of the item on the next. I've |
307 | % used |\sbox| here to capture colour changes properly, even though I have |
308 | % deep moral objections to the use of \LaTeX\ boxing commands. Anyway, |
309 | % I capture the text in box~0 and compare its width to the amount of space |
310 | % I have in the label box. If there's enough, I can just unbox the box; |
311 | % otherwise I build a vbox containing the label text and an empty hbox -- |
312 | % |\baselineskip| glue inserted between the two boxes makes sure we get |
313 | % the correct spacing between the two lines, and the vboxness of the vbox |
314 | % ensures that the baseline of my strange thing is the baseline of the |
315 | % \emph{bottom} box. I then bash the vbox on the nose, so as to make its |
316 | % width zero, and leave that as the result. Either way, I then add glue |
317 | % to left align whatever it is I've created. |
318 | % |
319 | % \begin{macrocode} |
320 | \def\nextlinelabel#1{% |
321 | \sbox\z@{#1}% |
322 | \ifdim\wd\z@>\labelwidth% |
323 | \setbox\z@\vbox{\box\z@\hbox{}}% |
324 | \wd\z@\z@% |
325 | \box\z@% |
326 | \else% |
327 | \unhbox\z@% |
328 | \fi% |
329 | \hfil% |
330 | } |
331 | % \end{macrocode} |
332 | % |
333 | % \end{macro} |
334 | % |
335 | % \begin{macro}{\multilinelabel} |
336 | % |
337 | % A different idea -- make the label text wrap around onto the next line if |
338 | % it's too long. This is really easy, actually. I use a parbox to contain |
339 | % the label text, set to be ragged right, because there won't be enough |
340 | % space to do proper justification. There's also a funny hskip there -- |
341 | % this is because \TeX\ only hyphenates things it finds sitting \emph{after} |
342 | % glue items. The parbox is top-aligned, so the label text and the item |
343 | % run downwards together. I put the result in box~0, and remove the depth, |
344 | % so as not to make the top line of the item text look really strange. |
345 | % |
346 | % All this leaves a little problem, though: if the item text isn't very long, |
347 | % the label might go further down the page than the main item, and possibly |
348 | % collide with the label below. I must confess that I'm not actually sure |
349 | % how to deal with this possibility, so I just hope it doesn't happen. |
350 | % |
351 | % By the way, I don't have moral objections to |\parbox|. |
352 | % |
353 | % \begin{macrocode} |
354 | \def\multilinelabel#1{% |
355 | \setbox\z@\hbox{% |
356 | \parbox[t]\labelwidth{\raggedright\hskip\z@skip#1}% |
357 | }% |
358 | \dp\z@\z@% |
359 | \box\z@% |
360 | \hfil% |
361 | } |
362 | % \end{macrocode} |
363 | % |
364 | % \end{macro} |
365 | % |
366 | % \begin{macro}{\pushlabel} |
367 | % |
368 | % Now we implement the old style behaviour -- if the label is too wide, we |
369 | % just push the first line of the item further over to the right. This |
370 | % is really very easy indeed -- we just stick some |\hfil| space on the |
371 | % right hand side (to left align if the label comes up too short). The |
372 | % `push' behaviour is handled automatically by \LaTeX's item handling. |
373 | % |
374 | % \begin{macrocode} |
375 | \def\pushlabel#1{{#1}\hfil} |
376 | % \end{macrocode} |
377 | % |
378 | % \end{macro} |
379 | % |
380 | % \subsubsection{The main environment} |
381 | % |
382 | % \begin{macro}{\desclabelstyle} |
383 | % |
384 | % This is a declaration intended to be used only in the argument to the |
385 | % \env{basedescript} environment. It sets the label style for the list. |
386 | % All we do is take the argument and assign it to a magic control sequence |
387 | % which \env{basedescript} will understand later. |
388 | % |
389 | % \begin{macrocode} |
390 | \def\desclabelstyle#1{\def\desc@labelstyle{#1}} |
391 | % \end{macrocode} |
392 | % |
393 | % \end{macro} |
394 | % |
395 | % \begin{macro}{\desclabelwidth} |
396 | % |
397 | % We set the label width and various other bits of information which will |
398 | % make all the bits of the description line up beautifully. We set |
399 | % |\labelwidth| to the value we're given (using |\setlength|, so that |
400 | % people can use the \package{calc} package if they so wish), and make |
401 | % the |\leftmargin| equal $|\labelwidth|+|\labelsep|$. |
402 | % |
403 | % \begin{macrocode} |
404 | \def\desclabelwidth#1{% |
405 | \setlength\labelwidth{#1}% |
406 | \leftmargin\labelwidth% |
407 | \advance\leftmargin\labelsep% |
408 | } |
409 | % \end{macrocode} |
410 | % |
411 | % \end{macro} |
412 | % |
413 | % \begin{environment}{basedescript} |
414 | % |
415 | % This is the new description environment. It does almost everything you |
416 | % could want from a description environment, I think. The argument is a |
417 | % collection of declarations to be performed while setting up the list. |
418 | % |
419 | % This environment isn't really intended to be used by users -- it's here |
420 | % so that you can define other description environments in terms of it, |
421 | % |
422 | % The environment is defined in two bits -- the `start' bit here simply |
423 | % starts the list and inserts the user declarations in an appropriate |
424 | % point, although sensible details will be inerted if the argument was |
425 | % empty. |
426 | % |
427 | % \begin{macrocode} |
428 | \def\basedescript#1{% |
429 | % \end{macrocode} |
430 | % |
431 | % We must start the list. If the |\item| command's optional argument is |
432 | % missing, we should just leave a blank space, I think. |
433 | % |
434 | % \begin{macrocode} |
435 | \list{}{% |
436 | % \end{macrocode} |
437 | % |
438 | % So far, so good. Now put in some default declarations. I'll use a |
439 | % separate macro for this, so that the global appearance of lists can be |
440 | % configured. |
441 | % |
442 | % \begin{macrocode} |
443 | \defaultdesc% |
444 | % \end{macrocode} |
445 | % |
446 | % Now we do the user's declarations. |
447 | % |
448 | % \begin{macrocode} |
449 | #1% |
450 | % \end{macrocode} |
451 | % |
452 | % Now set up the other parts of the list. We set |\itemindent| so that the |
453 | % label is up against the current left margin. (The standard version |
454 | % actually leaves the label hanging to the left of the margin by a |
455 | % distance of |\labelsep| for a reason I can't quite comprehend -- there's |
456 | % an |\hspace{\labelsep}| in the standard |\makelabel| to compensate for |
457 | % this. Strange\dots) |
458 | % |
459 | % To make the label start in the right place, the text of the item must |
460 | % start a distance of $|\labelwidth|+|\labelsep|$ from the (pre-list) left |
461 | % hand margin; this means that we must set |\itemindent| to be |
462 | % $|\labelwidth|+|\labelsep|-|\leftmargin|$. Time for some \TeX\ arithmetic. |
463 | % |
464 | % \begin{macrocode} |
465 | \itemindent\labelwidth% |
466 | \advance\itemindent\labelsep% |
467 | \advance\itemindent-\leftmargin% |
468 | % \end{macrocode} |
469 | % |
470 | % Now we must set up the label typesetting. We'll take the |\makelabel| |
471 | % provided by the user, remember it, and then redefine |\makelabel| in |
472 | % terms of the |\desclabelstyle| and the saved |\makelabel|. |
473 | % |
474 | % \begin{macrocode} |
475 | \let\desc@makelabel\makelabel% |
476 | \def\makelabel##1{\desc@labelstyle{\desc@makelabel{##1}}}% |
477 | % \end{macrocode} |
478 | % |
479 | % I can't think of anything else which needs doing, so I'll call it a day |
480 | % there. |
481 | % |
482 | % \begin{macrocode} |
483 | }% |
484 | } |
485 | % \end{macrocode} |
486 | % |
487 | % Now we define the `end-bit' of the environment. Since all we need to do |
488 | % is to close the list, we can be ever-so slightly clever and use |\let|. |
489 | % |
490 | % \begin{macrocode} |
491 | \let\endbasedescript\endlist |
492 | % \end{macrocode} |
493 | % |
494 | % Note that with these definitions, the standard \env{description} |
495 | % environment can be emulated by saying simply: |
496 | % \begin{listing} |
497 | %\renewenvironment{description}{% |
498 | % \begin{basedescript}{}% |
499 | %}{% |
500 | % \end{basedescript} |
501 | %} |
502 | % \end{listing} |
503 | % |
504 | % \end{environment} |
505 | % |
506 | % \begin{macro}{\defaultdesc} |
507 | % |
508 | % Now to set up the standard description appearance. In the absence |
509 | % of any other declarations, the label will `push' the text out the way if |
510 | % the text is too long. The standard |\labelsep| and |\leftmargin| are not |
511 | % our problem. We typeset the label text in bold by default. Also, |
512 | % |\labelwidth| is cleared to 0\,pt, because this is what \LaTeX's usual |
513 | % \env{description} does. |
514 | % |
515 | % \begin{macrocode} |
516 | \providecommand\defaultdesc{% |
517 | \desclabelstyle\pushlabel% |
518 | \def\makelabel##1{\bfseries##1}% |
519 | \labelwidth\z@% |
520 | } |
521 | % \end{macrocode} |
522 | % |
523 | % \end{macro} |
524 | % |
525 | % \subsubsection{An example} |
526 | % |
527 | % \begin{environment}{note} |
528 | % |
529 | % The \env{note} environment is a simple application of the general |
530 | % description list shown above. It typesets the label (by default, the |
531 | % text `\textbf{note}') at the left margin, and the note text indented by |
532 | % the width of the label. |
533 | % |
534 | % The code is simple -- we take the environment's argument (which may have |
535 | % been omitted), store it in a box (using |\sbox| again, to handle colour |
536 | % changes correctly), set the label width from the width of the box, and |
537 | % then create a single item containing the label text. The text of the |
538 | % environment then appears in exactly the desired place. |
539 | % |
540 | % I've not used |\newcommand| here, for the following reasons: |
541 | % \begin{itemize} |
542 | % |
543 | % \item I don't like it much, to be honest. |
544 | % |
545 | % \item Until very recently, |\newcommand| only allowed you to define |
546 | % `long' commands, where new paragraphs were allowed to be started |
547 | % in command arguments; this removes a useful check which traps |
548 | % common errors like missing out `|}|' characters. I'd prefer to |
549 | % be compatible with older \LaTeX s than to use the new |\newcommand| |
550 | % which provides a $*$-form to work around this restriction. |
551 | % |
552 | % \end{itemize} |
553 | % |
554 | % \begin{macrocode} |
93e82ea5 |
555 | \ifx\note\@@undefined |
556 | \def\note{\@ifnextchar[\note@i{\note@i[Note]}} |
557 | \def\note@i[#1]{% |
558 | \basedescript{% |
559 | \sbox\z@{\makelabel{#1}}% |
560 | \desclabelwidth{\wd\z@}% |
561 | }% |
562 | \item[\box\z@]% |
563 | } |
564 | \let\endnote\endbasedescript |
565 | \fi |
86f6a31e |
566 | % \end{macrocode} |
567 | % |
568 | % \end{environment} |
569 | % |
570 | % |
571 | % \subsection{Compacted environments} |
572 | % |
573 | % Normal lists tend to have rather too much space between items if all or |
574 | % most of the item texts are one line or less each. We therefore define |
575 | % a macro |\makecompactlist| whuch creates `compacted' versions of existing |
576 | % environments. |
577 | % |
578 | % \begin{macro}{\makecompactlist} |
579 | % |
580 | % We're given two arguments: the name of the new environment to create, and |
581 | % the name of the existing list environment to create. |
582 | % |
583 | % The first thing to do is to ensure that the environment we're creating is |
584 | % actually valid (i.e., it doesn't exist already, and it has a sensible |
585 | % name). We can do this with the internal \LaTeX\ macro |\@ifdefinable|. |
586 | % |
587 | % \begin{macrocode} |
588 | \def\makecompactlist#1#2{% |
589 | \expandafter\@ifdefinable\csname#1\endcsname% |
590 | {\makecompactlist@i{#1}{#2}}% |
591 | } |
592 | % \end{macrocode} |
593 | % |
594 | % We also ought to ensure that the other environment already exists. This |
595 | % isn't too tricky. We'll steal \LaTeX's error and message for this. |
596 | % |
597 | % \begin{macrocode} |
598 | \def\makecompactlist@i#1#2{% |
599 | \@ifundefined{#2}{\me@err{Environment `#2' not defined}\@ehc}{}% |
600 | % \end{macrocode} |
601 | % |
602 | % The main work for starting a compact list is done elsewhere. |
603 | % |
604 | % \begin{macrocode} |
605 | \@namedef{#1}{\@compact@list{#2}}% |
606 | % \end{macrocode} |
607 | % |
608 | % Now to define the end of the environment; this isn't terribly difficult. |
609 | % |
610 | % \begin{macrocode} |
611 | \expandafter\let\csname end#1\expandafter\endcsname% |
612 | \csname end#2\endcsname% |
613 | % \end{macrocode} |
614 | % |
615 | % That's a compacted environment created. Easy, no? |
616 | % |
617 | % \begin{macrocode} |
618 | } |
619 | % \end{macrocode} |
620 | % |
621 | % The general case macro has to try slurping some arguments, calling the |
622 | % underlying environment, and removing vertical space. |
623 | % |
624 | % \begin{macrocode} |
625 | \def\@compact@list#1{\@testopt{\@compact@list@i{#1}}{}} |
626 | \def\@compact@list@i#1[#2]{% |
627 | \@nameuse{#1}#2% |
628 | \parskip\z@% |
629 | \itemsep\z@% |
630 | }% |
631 | % \end{macrocode} |
632 | % |
633 | % \end{macro} |
634 | % |
635 | % \begin{environment}{itemize*} |
636 | % \begin{environment}{enumerate*} |
637 | % \begin{environment}{description*} |
638 | % |
639 | % Let's build some compacted environments now. These are easy now that |
640 | % we've done all the work above. |
641 | % |
642 | % \begin{macrocode} |
643 | \makecompactlist{itemize*}{itemize} |
644 | \makecompactlist{enumerate*}{enumerate} |
645 | \makecompactlist{description*}{description} |
646 | % \end{macrocode} |
647 | % |
648 | % \end{environment} |
649 | % \end{environment} |
650 | % \end{environment} |
651 | % |
652 | % |
653 | % \subsection{Suspending and resuming lists} |
654 | % |
655 | % This is nowhere near perfect; it relies a lot on the goodwill of the user, |
656 | % although it seems to work fairly well. |
657 | % |
658 | % \begin{macro}{\suspend} |
659 | % |
660 | % The only thing that needs saving here is the list counter, whose name |
661 | % is stored in |\@listctr|. When I get a request to save the counter, I'll |
662 | % build a macro which will restore it when the environment is restored later. |
663 | % |
664 | % The first thing to do is to handle the optional argument. |\@dblarg| will |
665 | % sort this out, giving me a copy of the mandatory argument if there's no |
666 | % optional one provided. |
667 | % |
668 | % \begin{macrocode} |
669 | \def\suspend{\@dblarg\suspend@i} |
670 | % \end{macrocode} |
671 | % |
672 | % That's all we need to do here. |
673 | % |
674 | % \begin{macrocode} |
675 | \def\suspend@i[#1]#2{% |
676 | % \end{macrocode} |
677 | % |
678 | % Now I have a little problem; when I |\end| the environment, it will close |
679 | % off the grouping level, and the counter value will be forgotten. This is |
680 | % bad. I'll store all my definitions into a macro, and build the |\end| |
681 | % command into it; that way, everything will be expanded correctly. This |
682 | % requires the use of |\edef|, which means I must be a little careful. |
683 | % |
684 | % \begin{macrocode} |
685 | \edef\@tempa{% |
686 | % \end{macrocode} |
687 | % |
688 | % The first thing to do is to end the environment. I don't want |\end| |
689 | % expanded yet, so I'll use |\noexpand|. |
690 | % |
691 | % \begin{macrocode} |
692 | \noexpand\end{#2}% |
693 | % \end{macrocode} |
694 | % |
695 | % Now I must define the `resume' macro. I'll use |\csname| to build the |
696 | % named identifier into the name, so it won't go wrong (maybe). There's |
697 | % a little fun here to make the control sequence name but not expand it |
698 | % here. |
699 | % |
700 | % \begin{macrocode} |
701 | \def\expandafter\noexpand\csname resume.#1\endcsname{% |
702 | % \end{macrocode} |
703 | % |
704 | % The counter name is hidden inside |\@listctr|, so the actual counter is |
705 | % called `|\csname c@\@listctr\endcsname|'. I'll use |\the| to read its |
706 | % current value, and assign it to the counter when the macro is used later. |
707 | % |
708 | % \begin{macrocode} |
709 | \csname c@\@listctr\endcsname\the\csname c@\@listctr\endcsname% |
710 | % \end{macrocode} |
711 | % |
712 | % That's all we need to do there. Now close the macros and run them. |
713 | % |
714 | % \begin{macrocode} |
715 | }% |
716 | }% |
717 | \@tempa% |
718 | } |
719 | % \end{macrocode} |
720 | % |
721 | % \end{macro} |
722 | % |
723 | % \begin{macro}{\resume} |
724 | % |
725 | % Resuming environments is much easier. Since I use |\csname| to build the |
726 | % name, nothing happens if you try to resume environments which weren't |
727 | % suspended. I'll trap this and raise an error. Provide an optional |
728 | % argument for collecting arguments to the target list. |
729 | % |
730 | % \begin{macrocode} |
731 | \def\resume{\@dblarg\resume@i} |
732 | \def\resume@i[#1]#2{\@testopt{\resume@ii{#1}{#2}}{}} |
733 | \def\resume@ii#1#2[#3]{% |
734 | \begin{#2}#3% |
735 | \@ifundefined{resume.#1}{\ml@err@resume}{\@nameuse{resume.#1}}% |
736 | } |
737 | % \end{macrocode} |
738 | % |
739 | % \end{macro} |
740 | % |
741 | % That's all there is. |
742 | % |
743 | % \begin{macrocode} |
744 | %</package> |
745 | % \end{macrocode} |
746 | % |
747 | % \hfill Mark Wooding, \today |
748 | % |
749 | % \Finale |
750 | % |
751 | \endinput |