86f6a31e |
1 | % \begin{meta-comment} <general public licence> |
2 | %% |
3 | %% mdwlist package -- various list-related things |
4 | %% Copyright (c) 1996 Mark Wooding |
5 | %% |
6 | %% This program is free software; you can redistribute it and/or modify |
7 | %% it under the terms of the GNU General Public License as published by |
8 | %% the Free Software Foundation; either version 2 of the License, or |
9 | %% (at your option) any later version. |
10 | %% |
11 | %% This program is distributed in the hope that it will be useful, |
12 | %% but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | %% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
14 | %% GNU General Public License for more details. |
15 | %% |
16 | %% You should have received a copy of the GNU General Public License |
17 | %% along with this program; if not, write to the Free Software |
18 | %% Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
19 | %% |
20 | % \end{meta-comment} |
21 | % |
22 | % \begin{meta-comment} <Package preambles> |
23 | %<+package>\NeedsTeXFormat{LaTeX2e} |
24 | %<+package>\ProvidesPackage{mdwlist} |
25 | %<+package> [1996/05/02 1.1 Various list-related things] |
26 | % \end{meta-comment} |
27 | % |
93e82ea5 |
28 | % \CheckSum{183} |
86f6a31e |
29 | %% \CharacterTable |
30 | %% {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 |
31 | %% 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 |
32 | %% Digits \0\1\2\3\4\5\6\7\8\9 |
33 | %% Exclamation \! Double quote \" Hash (number) \# |
34 | %% Dollar \$ Percent \% Ampersand \& |
35 | %% Acute accent \' Left paren \( Right paren \) |
36 | %% Asterisk \* Plus \+ Comma \, |
37 | %% Minus \- Point \. Solidus \/ |
38 | %% Colon \: Semicolon \; Less than \< |
39 | %% Equals \= Greater than \> Question mark \? |
40 | %% Commercial at \@ Left bracket \[ Backslash \\ |
41 | %% Right bracket \] Circumflex \^ Underscore \_ |
42 | %% Grave accent \` Left brace \{ Vertical bar \| |
43 | %% Right brace \} Tilde \~} |
44 | %% |
45 | % |
46 | % \begin{meta-comment} |
47 | % |
48 | %<*driver> |
49 | \input{mdwtools} |
50 | \describespackage{mdwlist} |
51 | \def\defaultdesc{% |
52 | \desclabelwidth{80pt}% |
53 | \desclabelstyle\nextlinelabel% |
54 | \def\makelabel{\bfseries}% |
55 | } |
56 | \newenvironment{cmdlist} |
57 | {\basedescript{\let\makelabel\cmd}} |
58 | {\endbasedescript} |
59 | \mdwdoc |
60 | %</driver> |
61 | % |
62 | % \end{meta-comment} |
63 | % |
64 | % \section{User guide} |
65 | % |
66 | % This package provides some vaguely useful list-related commands and |
67 | % environments: |
68 | % \begin{itemize*} |
69 | % \item A way of building \env{description}-like environments. |
70 | % \item Commands for making `compacted' versions of list environments |
71 | % \item A method for suspending and resuming enumerated lists. |
72 | % \end{itemize*} |
73 | % |
74 | % \subsection{Description list handling} |
75 | % |
76 | % Different sorts of description-type lists require different sorts of |
77 | % formatting: I think that's fairly obvious. There are essentially three |
78 | % different attributes which should be changable: |
79 | % \begin{itemize*} |
80 | % \item the indentation of the items being described, |
81 | % \item the handling of labels which don't fit properly, and |
82 | % \item the style used to typeset the label text. |
83 | % \end{itemize*} |
84 | % The first two items should usually be decided for all description-like |
85 | % lists in the document, to ensure consistency of appearance. The last |
86 | % depends much more on the content of the labels. |
87 | % |
88 | % \DescribeEnv{basedescript} |
89 | % The \env{basedescript} environment acts as a `skeleton' for description |
90 | % environments. It takes one argument, which contains declarations to |
91 | % be performed while constructing the list. I'd consider it unusual for |
92 | % the \env{basedescript} environment to be used in the main text: it's |
93 | % intended to be used to build other environments. |
94 | % |
95 | % The declarations which can be used to define description-type environments |
96 | % include all of those which are allowed when setting up a list (see the |
97 | % \LaTeX\ book for information here). Some others, which apply specifically |
98 | % to description lists, are also provided: |
99 | % |
100 | % \begin{itemize} |
101 | % |
102 | % \item \DescribeMacro{\desclabelwidth} |
103 | % The \syntax{"\\desclabelwidth{"<length>"}"} declaration sets labels |
104 | % to be left-aligned, with a standard width of \<length>; the item |
105 | % text is indented by \<length> plus the value of |\labelsep|. |
106 | % |
107 | % \item \DescribeMacro{\desclabelstyle} |
108 | % The label style determines how overlong labels are typeset. A style |
109 | % may be set using the \syntax{"\\desclabelstyle{"<style>"}"} |
110 | % declaration. The following \<style>s are provided: |
111 | % \begin{cmdlist} |
112 | % \item [\nextlinelabel] If the label is too wide to fit next to the |
113 | % first line of text, then it is placed on a line by itself; |
114 | % the main text is started on the next line with the usual |
115 | % indentation. |
116 | % \item [\multilinelabel] The label is typeset in a parbox with the |
117 | % appropriate width; if it won't fit on one line, then the |
118 | % text will be split onto subsequent lines. |
119 | % \item [\pushlabel] If the label is too wide to fit in the space |
120 | % allocated to it, the start of the item's text will be `pushed' |
121 | % over to the right to provide space for the label. This is |
122 | % the standard \LaTeX\ \env{description} behaviour. |
123 | % \end{cmdlist} |
124 | % |
125 | % \item \DescribeMacro{\makelabel} |
126 | % The |\makelabel| command is responsible for typesetting a label. |
127 | % It is given one argument, which is the text given as an argument |
128 | % to the |\item| command; it should typeset it appropriately. The |
129 | % text will then be arranged appropriately according to the chosen |
130 | % label style. This command should be redefined using |\renewcommand|. |
131 | % |
132 | % \end{itemize} |
133 | % |
134 | % \begin{figure} |
135 | % \begin{demo}[w]{Various labelling styles} |
136 | %\begin{basedescript}{\desclabelstyle{\nextlinelabel}} |
137 | %\item [Short label] This is a short item, although it has quite a |
138 | % lot of text attached to it. |
139 | %\item [Slightly longer label text] This is a rather longer piece |
140 | % of text, with a correspondingly slightly longer label. |
141 | %\end{basedescript} |
142 | %\medskip |
143 | %\begin{basedescript}{\desclabelstyle{\multilinelabel}} |
144 | %\item [Short label] This is a short item, although it has quite a |
145 | % lot of text attached to it. |
146 | %\item [Slightly longer label text] This is a rather longer piece |
147 | % of text, with a correspondingly slightly longer label. |
148 | %\end{basedescript} |
149 | %\medskip |
150 | %\begin{basedescript}{\desclabelstyle{\pushlabel}} |
151 | %\item [Short label] This is a short item, although it has quite a |
152 | % lot of text attached to it. |
153 | %\item [Slightly longer label text] This is a rather longer piece |
154 | % of text, with a correspondingly slightly longer label. |
155 | %\end{basedescript} |
156 | % \end{demo} |
157 | % \end{figure} |
158 | % |
159 | % \DescribeMacro{\defaultdesc} |
160 | % To allow document designers to control the global appearance of description |
161 | % lists, the |\defaultdesc| command may be redefined; it is called while |
162 | % setting up a new \env{basedescript} list, before performing the user's |
163 | % declarations. By default, it attempts to emulate the standard \LaTeX\ |
164 | % \env{description} environment:\footnote{^^A |
165 | % This is a slightly sanitised version of the real definition, which is |
166 | % given in the implementation section of this document.} |
167 | % \begin{listing} |
168 | %\providecommand{\defaultdesc}{% |
169 | % \desclabelstyle{\pushlabel}% |
170 | % \renewcommand{\makelabel}[1]{\bfseries##1}% |
171 | % \setlength{\labelwidth}{0pt}% |
172 | %} |
173 | % \end{listing} |
174 | % Unfortunately, \LaTeX\ doesn't provide a means for overriding a command |
175 | % which may or may not have been defined yet; in this case, I'd probably |
176 | % recommend using the \TeX\ primitive |\def| to redefine |\defaultdesc|. |
177 | % |
178 | % If you want to redefine the \env{description} environment in terms of |
179 | % the commands in this package, the following method is recommended: |
180 | % \begin{listing} |
181 | %\renewenvironment{description}{% |
182 | % \begin{basedescript}{% |
183 | % \renewcommand{\makelabel}[1]{\bfseries##1}% |
184 | % }% |
185 | %}{% |
186 | % \end{basedescript}% |
187 | %} |
188 | % \end{listing} |
189 | % This ensures that labels are typeset in bold, as is usual, but other |
190 | % properties of the list are determined by the overall document style. |
191 | % |
192 | % \subsection{Compacted lists} |
193 | % |
194 | % \LaTeX\ tends to leave a certain amount of vertical space between list |
195 | % items. While this is normally correct for lists in which the items are |
196 | % several lines long, it tends to look odd if all or almost all the items |
197 | % are only one line long. |
198 | % |
199 | % \DescribeMacro{\makecompactlist} |
200 | % The command |
201 | % \syntax{"\\makecompactlist{"<new-env-name>"}{"<old-env-name>"}"} |
202 | % defines a new environment \<new-env-name> to be a `compacted' version of |
203 | % the existing environment \<old-env-name>; i.e., the two environments are |
204 | % the same except that the compacted version leaves no space between items |
205 | % or paragraphs within the list. |
206 | % |
207 | % \DescribeEnv{itemize*} |
208 | % \DescribeEnv{enumerate*} |
209 | % \DescribeEnv{description*} |
210 | % So that the most common cases are already handled, the package creates |
211 | % compacted $*$-variants of the \env{itemize}, \env{enumerate} and |
212 | % \env{description} environments. These were created using the commands |
213 | % \begin{listing} |
214 | %\makecompactlist{itemize*}{itemize} |
215 | %\makecompactlist{enumerate*}{enumerate} |
216 | %\makecompactlist{description*}{description} |
217 | % \end{listing} |
218 | % |
219 | % Some list environments accept arguments. You can pass an argument to a |
220 | % list environment using an optional argument to its compact variant. For |
221 | % example, |
222 | % \begin{listing} |
223 | %\begin{foolist*}[{someargument}] |
224 | % \end{listing} |
225 | % |
226 | % \subsection{Suspending and resuming list environments} |
227 | % |
228 | % \DescribeMacro{\suspend} |
229 | % \DescribeMacro{\resume} |
230 | % The |\suspend| and |\resume| commands allow you to temporarily end a list |
231 | % environment and then pick it up where you left off. The syntax is fairly |
232 | % simple: |
233 | % |
234 | % \begin{grammar} |
235 | % |
236 | % <suspend-cmd> ::= \[[ |
237 | % "\\suspend" |
238 | % \begin{stack} \\ "[" <name> "]" \end{stack} "{" <env-name> "}" |
239 | % \]]% |
240 | % |
241 | % <resume-cmd> ::= \[[ |
242 | % "\\resume" |
243 | % \begin{stack} \\ "[" <name> "]" \end{stack} "{" <env-name> "}" |
244 | % \begin{stack} \\ "[" <text> "]" \end{stack} |
245 | % \]]% |
246 | % |
247 | % \end{grammar} |
248 | % |
249 | % The \<env-name> is the name of the environment; this will more often than |
250 | % not be the \env{enumerate} environment. The \<name> is a magic name you |
251 | % can use to identify the suspended environment; if you don't specify this, |
252 | % the environment name is used instead. |
253 | % |
254 | % \begin{demo}{Suspended environments} |
255 | %Here's some initial text. It's |
256 | %not very interesting. |
257 | %\begin{enumerate*} |
258 | %\item This is an item. |
259 | %\item This is another. |
260 | %\suspend{enumerate*} |
261 | %Some more commentry text. |
262 | %\resume{enumerate*} |
263 | %\item Another item. |
264 | %\end{enumerate*} |
265 | % \end{demo} |
266 | % |
267 | % You can pass arguments to a resumed list environment through the second |
268 | % optional argument of the |\resume| command. If, for example, you're using |
269 | % David Carlisle's \package{enumerate} package, you could say something like |
270 | % \begin{listing} |
271 | %\begin{enumerate}[\bfseries{Item} i] |
272 | %\item An item |
273 | %\item Another item |
274 | %\suspend{enumerate} |
275 | %Some intervening text. |
276 | %\resume{enumerate}[{[\bfseries{Item} i]}] |
277 | %\item Yet another item |
278 | %\end{enumerate} |
279 | % \end{listing} |
280 | % |
281 | % \implementation |
282 | % |
283 | % \section{Implementation} |
284 | % |
285 | % \begin{macrocode} |
286 | %<*package> |
287 | % \end{macrocode} |
288 | % |
289 | % \subsection{Description lists} |
290 | % |
291 | % \subsubsection{Label styles} |
292 | % |
293 | % \begin{macro}{\nextlinelabel} |
294 | % |
295 | % The idea here is that if the label is too long to fit in its box, we put |
296 | % it on its own line and start the text of the item on the next. I've |
297 | % used |\sbox| here to capture colour changes properly, even though I have |
298 | % deep moral objections to the use of \LaTeX\ boxing commands. Anyway, |
299 | % I capture the text in box~0 and compare its width to the amount of space |
300 | % I have in the label box. If there's enough, I can just unbox the box; |
301 | % otherwise I build a vbox containing the label text and an empty hbox -- |
302 | % |\baselineskip| glue inserted between the two boxes makes sure we get |
303 | % the correct spacing between the two lines, and the vboxness of the vbox |
304 | % ensures that the baseline of my strange thing is the baseline of the |
305 | % \emph{bottom} box. I then bash the vbox on the nose, so as to make its |
306 | % width zero, and leave that as the result. Either way, I then add glue |
307 | % to left align whatever it is I've created. |
308 | % |
309 | % \begin{macrocode} |
310 | \def\nextlinelabel#1{% |
311 | \sbox\z@{#1}% |
312 | \ifdim\wd\z@>\labelwidth% |
313 | \setbox\z@\vbox{\box\z@\hbox{}}% |
314 | \wd\z@\z@% |
315 | \box\z@% |
316 | \else% |
317 | \unhbox\z@% |
318 | \fi% |
319 | \hfil% |
320 | } |
321 | % \end{macrocode} |
322 | % |
323 | % \end{macro} |
324 | % |
325 | % \begin{macro}{\multilinelabel} |
326 | % |
327 | % A different idea -- make the label text wrap around onto the next line if |
328 | % it's too long. This is really easy, actually. I use a parbox to contain |
329 | % the label text, set to be ragged right, because there won't be enough |
330 | % space to do proper justification. There's also a funny hskip there -- |
331 | % this is because \TeX\ only hyphenates things it finds sitting \emph{after} |
332 | % glue items. The parbox is top-aligned, so the label text and the item |
333 | % run downwards together. I put the result in box~0, and remove the depth, |
334 | % so as not to make the top line of the item text look really strange. |
335 | % |
336 | % All this leaves a little problem, though: if the item text isn't very long, |
337 | % the label might go further down the page than the main item, and possibly |
338 | % collide with the label below. I must confess that I'm not actually sure |
339 | % how to deal with this possibility, so I just hope it doesn't happen. |
340 | % |
341 | % By the way, I don't have moral objections to |\parbox|. |
342 | % |
343 | % \begin{macrocode} |
344 | \def\multilinelabel#1{% |
345 | \setbox\z@\hbox{% |
346 | \parbox[t]\labelwidth{\raggedright\hskip\z@skip#1}% |
347 | }% |
348 | \dp\z@\z@% |
349 | \box\z@% |
350 | \hfil% |
351 | } |
352 | % \end{macrocode} |
353 | % |
354 | % \end{macro} |
355 | % |
356 | % \begin{macro}{\pushlabel} |
357 | % |
358 | % Now we implement the old style behaviour -- if the label is too wide, we |
359 | % just push the first line of the item further over to the right. This |
360 | % is really very easy indeed -- we just stick some |\hfil| space on the |
361 | % right hand side (to left align if the label comes up too short). The |
362 | % `push' behaviour is handled automatically by \LaTeX's item handling. |
363 | % |
364 | % \begin{macrocode} |
365 | \def\pushlabel#1{{#1}\hfil} |
366 | % \end{macrocode} |
367 | % |
368 | % \end{macro} |
369 | % |
370 | % \subsubsection{The main environment} |
371 | % |
372 | % \begin{macro}{\desclabelstyle} |
373 | % |
374 | % This is a declaration intended to be used only in the argument to the |
375 | % \env{basedescript} environment. It sets the label style for the list. |
376 | % All we do is take the argument and assign it to a magic control sequence |
377 | % which \env{basedescript} will understand later. |
378 | % |
379 | % \begin{macrocode} |
380 | \def\desclabelstyle#1{\def\desc@labelstyle{#1}} |
381 | % \end{macrocode} |
382 | % |
383 | % \end{macro} |
384 | % |
385 | % \begin{macro}{\desclabelwidth} |
386 | % |
387 | % We set the label width and various other bits of information which will |
388 | % make all the bits of the description line up beautifully. We set |
389 | % |\labelwidth| to the value we're given (using |\setlength|, so that |
390 | % people can use the \package{calc} package if they so wish), and make |
391 | % the |\leftmargin| equal $|\labelwidth|+|\labelsep|$. |
392 | % |
393 | % \begin{macrocode} |
394 | \def\desclabelwidth#1{% |
395 | \setlength\labelwidth{#1}% |
396 | \leftmargin\labelwidth% |
397 | \advance\leftmargin\labelsep% |
398 | } |
399 | % \end{macrocode} |
400 | % |
401 | % \end{macro} |
402 | % |
403 | % \begin{environment}{basedescript} |
404 | % |
405 | % This is the new description environment. It does almost everything you |
406 | % could want from a description environment, I think. The argument is a |
407 | % collection of declarations to be performed while setting up the list. |
408 | % |
409 | % This environment isn't really intended to be used by users -- it's here |
410 | % so that you can define other description environments in terms of it, |
411 | % |
412 | % The environment is defined in two bits -- the `start' bit here simply |
413 | % starts the list and inserts the user declarations in an appropriate |
414 | % point, although sensible details will be inerted if the argument was |
415 | % empty. |
416 | % |
417 | % \begin{macrocode} |
418 | \def\basedescript#1{% |
419 | % \end{macrocode} |
420 | % |
421 | % We must start the list. If the |\item| command's optional argument is |
422 | % missing, we should just leave a blank space, I think. |
423 | % |
424 | % \begin{macrocode} |
425 | \list{}{% |
426 | % \end{macrocode} |
427 | % |
428 | % So far, so good. Now put in some default declarations. I'll use a |
429 | % separate macro for this, so that the global appearance of lists can be |
430 | % configured. |
431 | % |
432 | % \begin{macrocode} |
433 | \defaultdesc% |
434 | % \end{macrocode} |
435 | % |
436 | % Now we do the user's declarations. |
437 | % |
438 | % \begin{macrocode} |
439 | #1% |
440 | % \end{macrocode} |
441 | % |
442 | % Now set up the other parts of the list. We set |\itemindent| so that the |
443 | % label is up against the current left margin. (The standard version |
444 | % actually leaves the label hanging to the left of the margin by a |
445 | % distance of |\labelsep| for a reason I can't quite comprehend -- there's |
446 | % an |\hspace{\labelsep}| in the standard |\makelabel| to compensate for |
447 | % this. Strange\dots) |
448 | % |
449 | % To make the label start in the right place, the text of the item must |
450 | % start a distance of $|\labelwidth|+|\labelsep|$ from the (pre-list) left |
451 | % hand margin; this means that we must set |\itemindent| to be |
452 | % $|\labelwidth|+|\labelsep|-|\leftmargin|$. Time for some \TeX\ arithmetic. |
453 | % |
454 | % \begin{macrocode} |
455 | \itemindent\labelwidth% |
456 | \advance\itemindent\labelsep% |
457 | \advance\itemindent-\leftmargin% |
458 | % \end{macrocode} |
459 | % |
460 | % Now we must set up the label typesetting. We'll take the |\makelabel| |
461 | % provided by the user, remember it, and then redefine |\makelabel| in |
462 | % terms of the |\desclabelstyle| and the saved |\makelabel|. |
463 | % |
464 | % \begin{macrocode} |
465 | \let\desc@makelabel\makelabel% |
466 | \def\makelabel##1{\desc@labelstyle{\desc@makelabel{##1}}}% |
467 | % \end{macrocode} |
468 | % |
469 | % I can't think of anything else which needs doing, so I'll call it a day |
470 | % there. |
471 | % |
472 | % \begin{macrocode} |
473 | }% |
474 | } |
475 | % \end{macrocode} |
476 | % |
477 | % Now we define the `end-bit' of the environment. Since all we need to do |
478 | % is to close the list, we can be ever-so slightly clever and use |\let|. |
479 | % |
480 | % \begin{macrocode} |
481 | \let\endbasedescript\endlist |
482 | % \end{macrocode} |
483 | % |
484 | % Note that with these definitions, the standard \env{description} |
485 | % environment can be emulated by saying simply: |
486 | % \begin{listing} |
487 | %\renewenvironment{description}{% |
488 | % \begin{basedescript}{}% |
489 | %}{% |
490 | % \end{basedescript} |
491 | %} |
492 | % \end{listing} |
493 | % |
494 | % \end{environment} |
495 | % |
496 | % \begin{macro}{\defaultdesc} |
497 | % |
498 | % Now to set up the standard description appearance. In the absence |
499 | % of any other declarations, the label will `push' the text out the way if |
500 | % the text is too long. The standard |\labelsep| and |\leftmargin| are not |
501 | % our problem. We typeset the label text in bold by default. Also, |
502 | % |\labelwidth| is cleared to 0\,pt, because this is what \LaTeX's usual |
503 | % \env{description} does. |
504 | % |
505 | % \begin{macrocode} |
506 | \providecommand\defaultdesc{% |
507 | \desclabelstyle\pushlabel% |
508 | \def\makelabel##1{\bfseries##1}% |
509 | \labelwidth\z@% |
510 | } |
511 | % \end{macrocode} |
512 | % |
513 | % \end{macro} |
514 | % |
515 | % \subsubsection{An example} |
516 | % |
517 | % \begin{environment}{note} |
518 | % |
519 | % The \env{note} environment is a simple application of the general |
520 | % description list shown above. It typesets the label (by default, the |
521 | % text `\textbf{note}') at the left margin, and the note text indented by |
522 | % the width of the label. |
523 | % |
524 | % The code is simple -- we take the environment's argument (which may have |
525 | % been omitted), store it in a box (using |\sbox| again, to handle colour |
526 | % changes correctly), set the label width from the width of the box, and |
527 | % then create a single item containing the label text. The text of the |
528 | % environment then appears in exactly the desired place. |
529 | % |
530 | % I've not used |\newcommand| here, for the following reasons: |
531 | % \begin{itemize} |
532 | % |
533 | % \item I don't like it much, to be honest. |
534 | % |
535 | % \item Until very recently, |\newcommand| only allowed you to define |
536 | % `long' commands, where new paragraphs were allowed to be started |
537 | % in command arguments; this removes a useful check which traps |
538 | % common errors like missing out `|}|' characters. I'd prefer to |
539 | % be compatible with older \LaTeX s than to use the new |\newcommand| |
540 | % which provides a $*$-form to work around this restriction. |
541 | % |
542 | % \end{itemize} |
543 | % |
544 | % \begin{macrocode} |
93e82ea5 |
545 | \ifx\note\@@undefined |
546 | \def\note{\@ifnextchar[\note@i{\note@i[Note]}} |
547 | \def\note@i[#1]{% |
548 | \basedescript{% |
549 | \sbox\z@{\makelabel{#1}}% |
550 | \desclabelwidth{\wd\z@}% |
551 | }% |
552 | \item[\box\z@]% |
553 | } |
554 | \let\endnote\endbasedescript |
555 | \fi |
86f6a31e |
556 | % \end{macrocode} |
557 | % |
558 | % \end{environment} |
559 | % |
560 | % |
561 | % \subsection{Compacted environments} |
562 | % |
563 | % Normal lists tend to have rather too much space between items if all or |
564 | % most of the item texts are one line or less each. We therefore define |
565 | % a macro |\makecompactlist| whuch creates `compacted' versions of existing |
566 | % environments. |
567 | % |
568 | % \begin{macro}{\makecompactlist} |
569 | % |
570 | % We're given two arguments: the name of the new environment to create, and |
571 | % the name of the existing list environment to create. |
572 | % |
573 | % The first thing to do is to ensure that the environment we're creating is |
574 | % actually valid (i.e., it doesn't exist already, and it has a sensible |
575 | % name). We can do this with the internal \LaTeX\ macro |\@ifdefinable|. |
576 | % |
577 | % \begin{macrocode} |
578 | \def\makecompactlist#1#2{% |
579 | \expandafter\@ifdefinable\csname#1\endcsname% |
580 | {\makecompactlist@i{#1}{#2}}% |
581 | } |
582 | % \end{macrocode} |
583 | % |
584 | % We also ought to ensure that the other environment already exists. This |
585 | % isn't too tricky. We'll steal \LaTeX's error and message for this. |
586 | % |
587 | % \begin{macrocode} |
588 | \def\makecompactlist@i#1#2{% |
589 | \@ifundefined{#2}{\me@err{Environment `#2' not defined}\@ehc}{}% |
590 | % \end{macrocode} |
591 | % |
592 | % The main work for starting a compact list is done elsewhere. |
593 | % |
594 | % \begin{macrocode} |
595 | \@namedef{#1}{\@compact@list{#2}}% |
596 | % \end{macrocode} |
597 | % |
598 | % Now to define the end of the environment; this isn't terribly difficult. |
599 | % |
600 | % \begin{macrocode} |
601 | \expandafter\let\csname end#1\expandafter\endcsname% |
602 | \csname end#2\endcsname% |
603 | % \end{macrocode} |
604 | % |
605 | % That's a compacted environment created. Easy, no? |
606 | % |
607 | % \begin{macrocode} |
608 | } |
609 | % \end{macrocode} |
610 | % |
611 | % The general case macro has to try slurping some arguments, calling the |
612 | % underlying environment, and removing vertical space. |
613 | % |
614 | % \begin{macrocode} |
615 | \def\@compact@list#1{\@testopt{\@compact@list@i{#1}}{}} |
616 | \def\@compact@list@i#1[#2]{% |
617 | \@nameuse{#1}#2% |
618 | \parskip\z@% |
619 | \itemsep\z@% |
620 | }% |
621 | % \end{macrocode} |
622 | % |
623 | % \end{macro} |
624 | % |
625 | % \begin{environment}{itemize*} |
626 | % \begin{environment}{enumerate*} |
627 | % \begin{environment}{description*} |
628 | % |
629 | % Let's build some compacted environments now. These are easy now that |
630 | % we've done all the work above. |
631 | % |
632 | % \begin{macrocode} |
633 | \makecompactlist{itemize*}{itemize} |
634 | \makecompactlist{enumerate*}{enumerate} |
635 | \makecompactlist{description*}{description} |
636 | % \end{macrocode} |
637 | % |
638 | % \end{environment} |
639 | % \end{environment} |
640 | % \end{environment} |
641 | % |
642 | % |
643 | % \subsection{Suspending and resuming lists} |
644 | % |
645 | % This is nowhere near perfect; it relies a lot on the goodwill of the user, |
646 | % although it seems to work fairly well. |
647 | % |
648 | % \begin{macro}{\suspend} |
649 | % |
650 | % The only thing that needs saving here is the list counter, whose name |
651 | % is stored in |\@listctr|. When I get a request to save the counter, I'll |
652 | % build a macro which will restore it when the environment is restored later. |
653 | % |
654 | % The first thing to do is to handle the optional argument. |\@dblarg| will |
655 | % sort this out, giving me a copy of the mandatory argument if there's no |
656 | % optional one provided. |
657 | % |
658 | % \begin{macrocode} |
659 | \def\suspend{\@dblarg\suspend@i} |
660 | % \end{macrocode} |
661 | % |
662 | % That's all we need to do here. |
663 | % |
664 | % \begin{macrocode} |
665 | \def\suspend@i[#1]#2{% |
666 | % \end{macrocode} |
667 | % |
668 | % Now I have a little problem; when I |\end| the environment, it will close |
669 | % off the grouping level, and the counter value will be forgotten. This is |
670 | % bad. I'll store all my definitions into a macro, and build the |\end| |
671 | % command into it; that way, everything will be expanded correctly. This |
672 | % requires the use of |\edef|, which means I must be a little careful. |
673 | % |
674 | % \begin{macrocode} |
675 | \edef\@tempa{% |
676 | % \end{macrocode} |
677 | % |
678 | % The first thing to do is to end the environment. I don't want |\end| |
679 | % expanded yet, so I'll use |\noexpand|. |
680 | % |
681 | % \begin{macrocode} |
682 | \noexpand\end{#2}% |
683 | % \end{macrocode} |
684 | % |
685 | % Now I must define the `resume' macro. I'll use |\csname| to build the |
686 | % named identifier into the name, so it won't go wrong (maybe). There's |
687 | % a little fun here to make the control sequence name but not expand it |
688 | % here. |
689 | % |
690 | % \begin{macrocode} |
691 | \def\expandafter\noexpand\csname resume.#1\endcsname{% |
692 | % \end{macrocode} |
693 | % |
694 | % The counter name is hidden inside |\@listctr|, so the actual counter is |
695 | % called `|\csname c@\@listctr\endcsname|'. I'll use |\the| to read its |
696 | % current value, and assign it to the counter when the macro is used later. |
697 | % |
698 | % \begin{macrocode} |
699 | \csname c@\@listctr\endcsname\the\csname c@\@listctr\endcsname% |
700 | % \end{macrocode} |
701 | % |
702 | % That's all we need to do there. Now close the macros and run them. |
703 | % |
704 | % \begin{macrocode} |
705 | }% |
706 | }% |
707 | \@tempa% |
708 | } |
709 | % \end{macrocode} |
710 | % |
711 | % \end{macro} |
712 | % |
713 | % \begin{macro}{\resume} |
714 | % |
715 | % Resuming environments is much easier. Since I use |\csname| to build the |
716 | % name, nothing happens if you try to resume environments which weren't |
717 | % suspended. I'll trap this and raise an error. Provide an optional |
718 | % argument for collecting arguments to the target list. |
719 | % |
720 | % \begin{macrocode} |
721 | \def\resume{\@dblarg\resume@i} |
722 | \def\resume@i[#1]#2{\@testopt{\resume@ii{#1}{#2}}{}} |
723 | \def\resume@ii#1#2[#3]{% |
724 | \begin{#2}#3% |
725 | \@ifundefined{resume.#1}{\ml@err@resume}{\@nameuse{resume.#1}}% |
726 | } |
727 | % \end{macrocode} |
728 | % |
729 | % \end{macro} |
730 | % |
731 | % That's all there is. |
732 | % |
733 | % \begin{macrocode} |
734 | %</package> |
735 | % \end{macrocode} |
736 | % |
737 | % \hfill Mark Wooding, \today |
738 | % |
739 | % \Finale |
740 | % |
741 | \endinput |