| 1 | % \begin{meta-comment} |
| 2 | % |
| 3 | % $Id: sverb.dtx,v 1.2 2003/09/05 16:09:30 mdw Exp $ |
| 4 | % |
| 5 | % Verbatim typesetting done properly (ahem) |
| 6 | % |
| 7 | % (c) 1996 Mark Wooding |
| 8 | % |
| 9 | % \end{meta-comment} |
| 10 | % |
| 11 | % \begin{meta-comment} <general public licence> |
| 12 | %% |
| 13 | %% sverb package -- handling of verbatim text |
| 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{sverb} |
| 35 | %<+package> [2003/09/04 1.4 Verbatim typesetting] |
| 36 | %<+colour>\NeedsTeXFormat{LaTeX2e} |
| 37 | %<+colour>\ProvidesPackage{svcolour} |
| 38 | %<+colour> [2003/09/04 1.4 Colour support for sverb] |
| 39 | %<+color>\NeedsTeXFormat{LaTeX2e} |
| 40 | %<+color>\ProvidesPackage{svcolor} |
| 41 | %<+color> [2003/09/04 1.4 Fix for people who can't spell] |
| 42 | %<+split>\NeedsTeXFormat{LaTeX2e} |
| 43 | %<+split>\ProvidesPackage{svsplit} |
| 44 | %<+split> [2003/09/04 1.4 Verbatim, but with line breaking] |
| 45 | % \end{meta-comment} |
| 46 | % |
| 47 | % \CheckSum{1011} |
| 48 | %% \CharacterTable |
| 49 | %% {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 |
| 50 | %% 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 |
| 51 | %% Digits \0\1\2\3\4\5\6\7\8\9 |
| 52 | %% Exclamation \! Double quote \" Hash (number) \# |
| 53 | %% Dollar \$ Percent \% Ampersand \& |
| 54 | %% Acute accent \' Left paren \( Right paren \) |
| 55 | %% Asterisk \* Plus \+ Comma \, |
| 56 | %% Minus \- Point \. Solidus \/ |
| 57 | %% Colon \: Semicolon \; Less than \< |
| 58 | %% Equals \= Greater than \> Question mark \? |
| 59 | %% Commercial at \@ Left bracket \[ Backslash \\ |
| 60 | %% Right bracket \] Circumflex \^ Underscore \_ |
| 61 | %% Grave accent \` Left brace \{ Vertical bar \| |
| 62 | %% Right brace \} Tilde \~} |
| 63 | %% |
| 64 | % |
| 65 | % \begin{meta-comment} |
| 66 | % |
| 67 | %<*driver> |
| 68 | \input{mdwtools} |
| 69 | \describespackage{sverb} |
| 70 | \describespackage{svcolour} |
| 71 | \describespackage{svsplit} |
| 72 | \mdwdoc |
| 73 | %</driver> |
| 74 | % |
| 75 | % \end{meta-comment} |
| 76 | % |
| 77 | % \section{User guide} |
| 78 | % |
| 79 | % The \package{sverb} package provides some useful commands and environments |
| 80 | % for doing things with verbatim text. I prefer this code to the standard |
| 81 | % \package{verbatim} package (by Rainer Sch\"opf et al.)\ although I'm |
| 82 | % biased. |
| 83 | % |
| 84 | % The package was written to fulfil a particular purpose: I wanted to be able |
| 85 | % to typeset ARM assembler code, 77~columns wide, on A5~paper, with the |
| 86 | % fields separated by \textit{tab} characters. It's grown up fairly |
| 87 | % organically from that, and I've tidied it when I've seen the code get too |
| 88 | % ugly. |
| 89 | % |
| 90 | % The current features are: |
| 91 | % |
| 92 | % \begin{itemize} |
| 93 | % |
| 94 | % \item A `listing' environment which typesets verbatim text nicely. |
| 95 | % |
| 96 | % \item A command to read verbatim text from an external file. |
| 97 | % |
| 98 | % \item Support for arbitrary-sized chunks of text without overflowing \TeX's |
| 99 | % memory. |
| 100 | % |
| 101 | % \item Support for \textit{tab} characters in the verbatim text. |
| 102 | % |
| 103 | % \item An environment for typesetting demonstrations of \LaTeX\ markup. |
| 104 | % |
| 105 | % \item It all works correctly with the \package{doc} system for documenting |
| 106 | % \LaTeX\ packages. |
| 107 | % |
| 108 | % \item A fairly hairy but quite powerful programmer interface to the yukky |
| 109 | % bits of the package. |
| 110 | % |
| 111 | % \end{itemize} |
| 112 | % |
| 113 | % The interface is described in its own section, so that more timid readers |
| 114 | % can avoid it. That said, some of the stuff in this section gets rather |
| 115 | % technical. |
| 116 | % |
| 117 | % Note that this package doesn't even try to do anything with short bits of |
| 118 | % verbatim text (as handled by the |\verb:...:| command). I have a separate |
| 119 | % package (\package{syntax}) which does all sorts of horrible things along |
| 120 | % those lines. |
| 121 | % |
| 122 | % \subsection{The \env{listing} environment} |
| 123 | % |
| 124 | % \DescribeEnv{listing} |
| 125 | % The main method for typesetting verbatim text is the \env{listing} |
| 126 | % environment. This works pretty much the same as the standard |
| 127 | % \env{verbatim} environment, with some exceptions, which are described |
| 128 | % below. |
| 129 | % |
| 130 | % So that you know exactly what you're getting, here are the rules by which |
| 131 | % \package{sverb} decides what the verbatim text actually is: |
| 132 | % |
| 133 | % \begin{itemize} |
| 134 | % |
| 135 | % \item If there's any text, other than spaces, on the same line as the |
| 136 | % `|\begin{listing}|', then the contents of the environment begins |
| 137 | % immediately after the closing brace (with all leading spaces |
| 138 | % preserved). Otherwise, the text begins on the following line. |
| 139 | % |
| 140 | % \item If there is any text, other than spaces, before the |
| 141 | % `|\end{listing}|', but on the same line, this is considered to be the |
| 142 | % last line of the text; otherwise the text is presumed to have ended |
| 143 | % at the end of the previous line. |
| 144 | % |
| 145 | % \item Any text following the |\end{listing}| on the same line is thrown |
| 146 | % away. There are good reasons for this, but they're technical. |
| 147 | % Essentially there's nothing I can do about it. |
| 148 | % |
| 149 | % \end{itemize} |
| 150 | % |
| 151 | % \begin{figure} |
| 152 | % \begin{demo}[w]{The \env{listing} environment} |
| 153 | %\dots in the following code: |
| 154 | % |
| 155 | %\begin{listing} |
| 156 | %init MOV R0,#200 ;Version 2.00 please |
| 157 | % LDR R1,=&4B534154 ;Magic number (`TASK') |
| 158 | % ADR R2,appName ;Find application name |
| 159 | % SWI Wimp_Initialise ;Register as a WIMP task |
| 160 | %\end{listing} |
| 161 | % |
| 162 | %The next step is to \dots |
| 163 | % \end{demo} |
| 164 | % \end{figure} |
| 165 | % |
| 166 | % Tab characters are supported within the environment: tab stops are set |
| 167 | % every eighth column, although this can be modified. |
| 168 | % |
| 169 | % \subsubsection{Configuring the \env{listing} environment} |
| 170 | % |
| 171 | % \DescribeMacro\listingsize |
| 172 | % The text size used in the \env{listing} environment is set by the |
| 173 | % |\listingsize| command. By default, this is set to |\footnotesize|, |
| 174 | % although you can redefine it in the document preamble, or it can be set in |
| 175 | % the document class. You can put other declarations (e.g., colours) here if |
| 176 | % you like. |
| 177 | % |
| 178 | % \DescribeMacro\listingindent |
| 179 | % The amount by which the listing text is indented is controlled by the |
| 180 | % |\listingindent| length parameter. This is a fixed length, whose default |
| 181 | % value is 1\,em. |
| 182 | % |
| 183 | % \DescribeMacro\listinghook |
| 184 | % \DescribeMacro\svafter |
| 185 | % \DescribeMacro\svline |
| 186 | % \DescribeMacro\svdoline |
| 187 | % \DescribeEnv{listinglist} |
| 188 | % The |\listinghook| command is called by the \env{listing} environment (and |
| 189 | % |\verbinput| and \env{demo}) to set up the formatting of the listing. It |
| 190 | % can do any setting up it likes, and may configure |\svline| and |\svafter| |
| 191 | % as necessary. The macro |\svline| is run once for each line of verbatim |
| 192 | % text, with the line gathered into a box register, the number of which is |
| 193 | % given as an argument. The macro |\svafter| is called when processing has |
| 194 | % finished. |
| 195 | % |
| 196 | % The default setting for |\listinghook| is (similar to) |
| 197 | %\begin{listing} |
| 198 | %\newcommand{\listinghook}{% |
| 199 | % \par% |
| 200 | % \begin{listinglist}% |
| 201 | % \listingsize% |
| 202 | % \renewcommand{\svline}{\listingline}% |
| 203 | % \renewcommand{\svafter}{\end{listinglist}}% |
| 204 | %} |
| 205 | %\end{listing} |
| 206 | % (see the source for the true definition). The default |\listingline| macro |
| 207 | % just writes out the line using |\svdoline|, which is a simple no-nonsense |
| 208 | % macro which just writes the text. As an example, you could say |
| 209 | %\begin{listing} |
| 210 | %\renewcommand{\listingline}{\leavevmode\llap{\strut\vrule\space}\svdoline} |
| 211 | %\end{listing} |
| 212 | % to put a rule down the left-hand side of your listings. |
| 213 | % |
| 214 | % The \env{listinglist} environment is a relatively straightforward |
| 215 | % \env{list}-based environment which sets pu the indentation of a listing. |
| 216 | % Feel free to redefine it. |
| 217 | % |
| 218 | % \subsubsection{Choosing a different end-text} |
| 219 | % |
| 220 | % \DescribeEnv{listing*} |
| 221 | % The \env{listing} environment is terminated by the exact character sequence |
| 222 | % `|\end{listing}|'. This isn't too much of a problem, unless you want to |
| 223 | % include this string in the text. This is achieved by the \env{listing$*$} |
| 224 | % environment, which allows you to specify the end-text to find as an |
| 225 | % argument. |
| 226 | % |
| 227 | % For example: |
| 228 | % |
| 229 | % \begin{demo}{The \env{listing$*$} environment} |
| 230 | %Type a listing as follows: |
| 231 | % |
| 232 | %\begin{listing*}{<end-listing*>} |
| 233 | %\begin{listing} |
| 234 | %This is a listing. Yes. |
| 235 | %\end{listing} |
| 236 | %<end-listing*> |
| 237 | %\end{demo} |
| 238 | % |
| 239 | % Don't include `special' characters in your chosen end-text unless you know |
| 240 | % what you're doing. |
| 241 | % |
| 242 | % \subsection{Writing text to a file} |
| 243 | % |
| 244 | % \DescribeEnv{verbwrite} |
| 245 | % You can write verbatim text to a file using the \env{verbwrite} |
| 246 | % environment. The syntax is fairly straightforward: |
| 247 | % |
| 248 | % \begin{quote} |
| 249 | % \syntax{"\\begin{verbwrite}{"<file-name>"}" \dots "\\end{verbwrite}"} |
| 250 | % \end{quote} |
| 251 | % |
| 252 | % The text of the environment is written to the named file. The rules about |
| 253 | % where the text actually starts and ends are the same as for the |
| 254 | % \env{listing} environment. |
| 255 | % |
| 256 | % There is also a $*$-variant, like \env{listing$*$}, which allows you to |
| 257 | % choose the end-text. The end-text is the first argument, the filename |
| 258 | % comes second. |
| 259 | % |
| 260 | % There is a restriction on the characters you can write to the file: they |
| 261 | % must all be considered `printable' by \TeX; otherwise they will be read |
| 262 | % back in as `\syntax{"^^"<chars>}' which isn't too good. Unfortunately, |
| 263 | % this includes tab characters, so you can't write them.\footnote{^^A |
| 264 | % Well, not without doing serious surgery on \TeX\ itself, anyway. } |
| 265 | % |
| 266 | % \iffalse [Example time... Ho hum. There is evilness here.] \fi |
| 267 | %\begin{verbwrite*}{<end-write>}{wrdemo1.tmp} |
| 268 | %\begin{verbwrite}{wrdemo.tmp} |
| 269 | %This is some text written to |
| 270 | %a file near the beginning of |
| 271 | %the file. |
| 272 | %\end{verbwrite} |
| 273 | %<end-write> |
| 274 | % |
| 275 | % For example: \verbinput{wrdemo1.tmp} |
| 276 | % |
| 277 | % \input{wrdemo1.tmp} \iffalse [Now build the file ;-) ] \fi |
| 278 | % |
| 279 | % \subsection{The \cmd\verbinput\ command} |
| 280 | % |
| 281 | % \DescribeMacro{\verbinput} |
| 282 | % You can input a pre-prepared text file exactly as it is in the input using |
| 283 | % the |\verbinput| command. The filename is given as an argument. For |
| 284 | % example: |
| 285 | % |
| 286 | % \begin{demo}{The \cmd\verbinput\ command} |
| 287 | %\verbinput{wrdemo.tmp} |
| 288 | % \end{demo} |
| 289 | % |
| 290 | % \subsection{The \env{demo} environment} |
| 291 | % |
| 292 | % Package authors need to document their packages, and it's common to want |
| 293 | % to display examples showing the original text and the output side-by-side |
| 294 | % (or, when space doesn't permit this, one above the other). Both the |
| 295 | % \LaTeX\ book and \textit{The \LaTeX\ Companion} contain such examples. |
| 296 | % |
| 297 | % The \env{demo} environment allows such displays to be created easily. The |
| 298 | % syntax of the environment is as follows: |
| 299 | % |
| 300 | % \begin{quote} |
| 301 | % \syntax{"\\begin{demo}["<shape>"]{"<title>"}" \dots "\\end{demo}"} |
| 302 | % \end{quote} |
| 303 | % |
| 304 | % The optional \synt{shape} argument can be either `|w|' (wide), or `|n|' |
| 305 | % (narrow). A `wide' shape places the input and output one above the other, |
| 306 | % while the `narrow' shape puts them side-by-side. The default shape is |
| 307 | % `narrow'. An attractive border is drawn around the display to finish it |
| 308 | % off nicely. |
| 309 | % |
| 310 | % An example: |
| 311 | % |
| 312 | %\begin{demo*}{<end-demo>}[w]{The \env{demo} environment} |
| 313 | %\begin{demo}{From the \textit{\TeX book}} |
| 314 | %\[ \sum_{p\;\rm prime} |
| 315 | % f(p) = \int_{t>1} |
| 316 | % f(t)\,{\rm d}\pi(t) \] |
| 317 | %\end{demo} |
| 318 | %<end-demo> |
| 319 | % |
| 320 | % \DescribeEnv{demo*} |
| 321 | % As with the other environments created by this package, there's a |
| 322 | % $*$-variant which takes the end-text as an argument. |
| 323 | % |
| 324 | % \DescribeMacro\demohook |
| 325 | % The |\demohook| does the same job for \env{demo} environments as |
| 326 | % |\listinghook| does for \env{listing}s. The default version just says |
| 327 | %\begin{listing} |
| 328 | %\newcommand{\demohook}{\setlength{\listingindent}{0pt}\listinghook} |
| 329 | %\end{listing} |
| 330 | % (near enough), which turns off the indentation for the listing (which would |
| 331 | % otherwise look rather odd). |
| 332 | % |
| 333 | % |
| 334 | % \section{Programmer interface} |
| 335 | % |
| 336 | % This section describes the publicly available routines provided by the |
| 337 | % \package{sverb} package. Routines not described here are libable to be |
| 338 | % changed or even removed without warning, so don't use them. |
| 339 | % |
| 340 | % \subsection{Environment hooks} |
| 341 | % |
| 342 | % Each of the environments created here works in the same way. For each |
| 343 | % environment \env{foo}, there's a main command responsible for doing the |
| 344 | % work, called |\sv@foo|. This is given all the arguments of the normal |
| 345 | % environment, and two more: |
| 346 | % |
| 347 | % \begin{itemize} |
| 348 | % |
| 349 | % \item The `end-text' to search for, which marks the end of the environment. |
| 350 | % |
| 351 | % \item Some actions to perform after the text has been read and processed. |
| 352 | % This allows the calling macro to do some extra actions, like closing |
| 353 | % boxes, etc. |
| 354 | % |
| 355 | % \end{itemize} |
| 356 | % |
| 357 | % All the environments do is call the main command with appropriate |
| 358 | % arguments. |
| 359 | % |
| 360 | % \subsection{Reading the verbatim text} |
| 361 | % |
| 362 | % \DescribeMacro{\sv@read} |
| 363 | % The main scanning routine is |\sv@read|. It is called with three |
| 364 | % arguments: |
| 365 | % |
| 366 | % \begin{itemize} |
| 367 | % |
| 368 | % \item The end-text marking the end of the environment. |
| 369 | % |
| 370 | % \item The name of a macro (which must be a single token) which is called |
| 371 | % with a line of text as its single argument. This is given each |
| 372 | % line of text which is read from the environment in turn. |
| 373 | % |
| 374 | % \item A macro, or other sort of action, which is to be done when the text |
| 375 | % has been read and processed. |
| 376 | % |
| 377 | % \end{itemize} |
| 378 | % |
| 379 | % The macro |\sv@read| assumes that the caller has already made some |
| 380 | % provision for removing the category codes of the following text, by either |
| 381 | % calling |\@verbatim| or using the construction |
| 382 | % \begin{listing} |
| 383 | %\let\do=\@makeother |
| 384 | %\dospecials |
| 385 | % \end{listing} |
| 386 | % |
| 387 | % \DescribeMacro{\sv@safespc} |
| 388 | % Note that any space characters you read using |\sv@read| will be catcoded |
| 389 | % as |\active|. Normally this is OK because |\obeyspaces| (or |
| 390 | % |\@vobeyspaces|) will be in effect. If you're doing something more exotic, |
| 391 | % like writing text to a file or building a command string, you can call |
| 392 | % |\sv@safespc| which defines the active-space character to be a normal |
| 393 | % whitespace-space when expanded. |
| 394 | % |
| 395 | % \section{Colour support} |
| 396 | % |
| 397 | % There's now a little colour support in \package{sverb}. To use it, give |
| 398 | % the \textsf{colour} (or \textsf{color}) package option, or load the |
| 399 | % \package{svcolour} package. |
| 400 | % |
| 401 | % \DescribeMacro\svcolourline |
| 402 | % Say \syntax{"\\svcolourline["<model>"]{"<colour>"}{"<box>"}"} to typeset |
| 403 | % \<box> against a background of the given colour. This is a good thing to |
| 404 | % put in your |\listingline| command. |
| 405 | %\begin{demo}{Coloured listings} |
| 406 | %\renewcommand{\listingline} |
| 407 | % {\svcolourline[rgb]{1, 0.8, 0.9}} |
| 408 | %Consider, for example, this more |
| 409 | %complicated program. |
| 410 | %\begin{listing} |
| 411 | %#include <stdio.h> |
| 412 | % |
| 413 | %int main(void) |
| 414 | %{ |
| 415 | % puts("Hello, world!"); |
| 416 | % return (0); |
| 417 | %} |
| 418 | %\end{listing} |
| 419 | %\end{demo} |
| 420 | % For coloured text rather than background, put a |\color| command in |
| 421 | % |\listinghook| itself. |
| 422 | % |
| 423 | % \section{The \package{svsplit} package} |
| 424 | % |
| 425 | % A new toy! |
| 426 | % |
| 427 | % \DescribeEnv{splitverb} |
| 428 | % \DescribeEnv{splitverb*} |
| 429 | % \DescribeMacro\svsplitchars |
| 430 | % The \env{splitverb} environment typesets verbatim material very slowly. On |
| 431 | % the plus side, however, it does know how to do simple line-breaking. It |
| 432 | % will break lines at spaces or tabs, or after any character listed in |
| 433 | % |\svsplitchars|. Continuation lines have the same initial intentation as |
| 434 | % the original. If a line has no `good' breaking point, it's broken as late |
| 435 | % as possible, and a little hyphen is inserted. |
| 436 | %\begin{demo}[w]{The \env{splitverb} environment} |
| 437 | %\begin{multicols}{2} |
| 438 | %\begin{splitverb} |
| 439 | %The \package{url} package is rather fine at splitting up long URLs such as |
| 440 | % \url{http://www.excessus.demon.co.uk/tex} |
| 441 | %though it can't do its thing in the midst of verbatim text. It |
| 442 | %also doesn't cope when |
| 443 | % allthespacesinalongphrasehavemysteriouslydisappeared! |
| 444 | %\end{splitverb} |
| 445 | %\end{multicols} |
| 446 | %\end{demo} |
| 447 | % |
| 448 | % \implementation |
| 449 | % |
| 450 | % \section{Implementation} |
| 451 | % |
| 452 | % This section defines several macros and environments which allow verbatim |
| 453 | % typing, with a high degree of configurability. OK, so this sort of |
| 454 | % thing's been done so often before that it isn't true, but I don't really |
| 455 | % care. |
| 456 | % |
| 457 | % \begin{macrocode} |
| 458 | %<*package> |
| 459 | % \end{macrocode} |
| 460 | % |
| 461 | % \subsection{Options processing} |
| 462 | % |
| 463 | % Notice options, load package. |
| 464 | % |
| 465 | % \begin{macrocode} |
| 466 | \newif\ifsv@colour\sv@colourfalse |
| 467 | \DeclareOption{colour}{\sv@colourtrue} |
| 468 | \DeclareOption{color}{\sv@colourtrue} |
| 469 | \ProcessOptions |
| 470 | % \end{macrocode} |
| 471 | % |
| 472 | % \subsection{Simple things} |
| 473 | % |
| 474 | % To help us build funny macros which involve strange and different category |
| 475 | % codes, I'll write some simple macros which I can use while building my |
| 476 | % complicated and clever ones. |
| 477 | % |
| 478 | % \begin{macro}{\@cspecials} |
| 479 | % |
| 480 | % This macro is used to assist the definition of some of the environments. |
| 481 | % It makes `|\|', `|{|' and `|}|' into `other' characters, and replaces them |
| 482 | % with `\verb"|"', `|<|' and `|>|' respectively. Note that `|[|' and `|]|' |
| 483 | % aren't used, because they make defining commands which take optional |
| 484 | % arguments awkward. Note that we open a group here. This should be closed |
| 485 | % using \verb"|endgroup" at the end of the special section. |
| 486 | % |
| 487 | % \begin{macrocode} |
| 488 | \def\@cspecials{% |
| 489 | \begingroup% |
| 490 | \catcode`|0% |
| 491 | \catcode`<1% |
| 492 | \catcode`>2% |
| 493 | \catcode`\{12% |
| 494 | \catcode`\}12% |
| 495 | \catcode`\\12% |
| 496 | } |
| 497 | % \end{macrocode} |
| 498 | % \end{macro} |
| 499 | % |
| 500 | % \begin{macro}{\sv@addtobox} |
| 501 | % |
| 502 | % Add stuff to a horizontal box. |
| 503 | % |
| 504 | % \begin{macrocode} |
| 505 | \def\sv@addtobox#1#2{\setbox#1\hbox{\unhbox#1\box#2}} |
| 506 | % \end{macrocode} |
| 507 | % |
| 508 | % \end{macro} |
| 509 | % |
| 510 | % \begin{macro}{\sv@emptybox} |
| 511 | % |
| 512 | % Clear out a horizontal box. |
| 513 | % |
| 514 | % \begin{macrocode} |
| 515 | \def\sv@emptybox#1{\setbox#1\hbox{}} |
| 516 | % \end{macrocode} |
| 517 | % |
| 518 | % \end{macro} |
| 519 | % |
| 520 | % \begin{macro}{\sv@startlisting} |
| 521 | % |
| 522 | % This macro sets everything up nicely for a \env{listing}-type verbatim |
| 523 | % environment. |
| 524 | % |
| 525 | % \begin{macrocode} |
| 526 | \def\sv@startlisting{% |
| 527 | \def\par{\@@par\penalty\interlinepenalty}% |
| 528 | \@@par% |
| 529 | \leftskip\@totalleftmargin% |
| 530 | \obeylines% |
| 531 | \@noligs% |
| 532 | \let\do\@makeother\dospecials% |
| 533 | \verbatim@font% |
| 534 | \frenchspacing% |
| 535 | \@vobeyspaces% |
| 536 | \settabwidth% |
| 537 | \catcode9\active% |
| 538 | \lccode`\~9\lowercase{\let~\sv@vtab}% |
| 539 | \lccode`\~13\lowercase{\let~\vinput@cr}% |
| 540 | \interlinepenalty500% |
| 541 | } |
| 542 | % \end{macrocode} |
| 543 | % |
| 544 | % \end{macro} |
| 545 | % |
| 546 | % \subsection{Tab character handling} |
| 547 | % |
| 548 | % One of the things we want to do here is handle tab characters properly. |
| 549 | % (Here, `properly' means `moving to the next column which is a multiple of |
| 550 | % eight', the way these things were always meant to.) |
| 551 | % |
| 552 | % \begin{macro}{\settabwidth} |
| 553 | % |
| 554 | % The tabs used by our tabbed verbatim environments are set up by this |
| 555 | % routine. It sets the tab width parameter |\svtab| to 8 times the width |
| 556 | % of a |\tt| space. If you really want, you can redefine this macro. |
| 557 | % |
| 558 | % \begin{macrocode} |
| 559 | \newdimen\svtab |
| 560 | \def\settabwidth{\setbox\z@\hbox{\texttt{\space}}\svtab8\wd\z@} |
| 561 | % \end{macrocode} |
| 562 | % |
| 563 | % \end{macro} |
| 564 | % |
| 565 | % \begin{macro}{\sv@vtab} |
| 566 | % |
| 567 | % Here we handle tabs inside verbatim environments. We expect to be inside |
| 568 | % |\box|~0. This is padded to the correct width and contributed to |\box|~2; |
| 569 | % |\box|~0 is then cleared and re-entered. |
| 570 | % |
| 571 | % The idea is that you make tab active, and set it to this macro. We stop |
| 572 | % the current box, stretch it to the right width, and start another one |
| 573 | % straight after, so nobody knows the difference. The code here is straight |
| 574 | % from Appendix~D of \textit{The \TeX book}. |
| 575 | % |
| 576 | % \begin{macrocode} |
| 577 | \def\sv@vtab{% |
| 578 | \hfill\egroup% |
| 579 | \@tempdima\wd\z@% |
| 580 | \divide\@tempdima\svtab% |
| 581 | \multiply\@tempdima\svtab% |
| 582 | \advance\@tempdima\svtab% |
| 583 | \wd\z@\@tempdima% |
| 584 | \sv@addtobox\tw@\z@% |
| 585 | \setbox\z@\hbox\bgroup% |
| 586 | } |
| 587 | % \end{macrocode} |
| 588 | % |
| 589 | % \end{macro} |
| 590 | % |
| 591 | % \begin{macro}{\verbinput} |
| 592 | % |
| 593 | % We allow input from a file, by the |\verbinput| command. We display the |
| 594 | % text pretty much the same as the \env{listing} environment below. |
| 595 | % |
| 596 | % We set tab and return active, and get them to do appropriate things. This |
| 597 | % isn't actually all that hard. |
| 598 | % |
| 599 | % \begin{macrocode} |
| 600 | \def\verbinput{\listinghook\@ifstar{\verbinput@\@input}{\verbinput@\input}} |
| 601 | \def\verbinput@#1#2{% |
| 602 | \sv@startlisting% |
| 603 | \setbox\z@\hbox\bgroup% |
| 604 | #1{#2}% |
| 605 | \sv@stripspc% |
| 606 | \egroup% |
| 607 | \sv@addtobox\tw@\z@% |
| 608 | \ifdim\wd\tw@=\z@\listingline\tw@\fi% |
| 609 | \svafter% |
| 610 | } |
| 611 | % \end{macrocode} |
| 612 | % |
| 613 | % \end{macro} |
| 614 | % |
| 615 | % \begin{macro}{\vinput@cr} |
| 616 | % |
| 617 | % This macro handles return characters while inputting text in |\verbinput|. |
| 618 | % We just output our current box, and start another. |
| 619 | % |
| 620 | % \begin{macrocode} |
| 621 | \def\vinput@cr{% |
| 622 | \egroup% |
| 623 | \sv@addtobox\tw@\z@% |
| 624 | \listingline\tw@% |
| 625 | \sv@emptybox\tw@% |
| 626 | \setbox\z@\hbox\bgroup% |
| 627 | } |
| 628 | % \end{macrocode} |
| 629 | % |
| 630 | % \end{macro} |
| 631 | % |
| 632 | % \subsection{Reading verbatim text} |
| 633 | % |
| 634 | % The traditional way of reading verbatim text is to use a delimited |
| 635 | % argument, as described in the \textit{\TeX book}. This works well-ish if |
| 636 | % the text isn't very long. A better solution would be to pick out the text |
| 637 | % line-by-line and process it like that. So this is what we do. |
| 638 | % |
| 639 | % \begin{macro}{\matcher} |
| 640 | % |
| 641 | % For long verbatim environments, we need to be able to find the end text. |
| 642 | % This is rather tricky. The solution here is rather horrible. The |
| 643 | % environment picks out each line of the text at a time, as an argument, and |
| 644 | % tests to see if it contains the text we're after. We do the test in a |
| 645 | % particularly yukky way: we add the actual target text to the end of the |
| 646 | % line, and inspect the text following the match to see if the match is at |
| 647 | % the end. |
| 648 | % |
| 649 | % The |\matcher| macro creates a `matcher' which will test strings to see if |
| 650 | % they contain something interesting. |
| 651 | % |
| 652 | % To create a matcher, say |
| 653 | % \syntax{"\\matcher{"<cmd-name>"}{"<target>"}{"<process-cmd>"}"}. The |
| 654 | % command \synt{cmd-name} accepts a line of text as an argument and calls |
| 655 | % the \synt{process-cmd} with the text of the line before the match, or the |
| 656 | % whole lot. It also sets |\@ifmatched| appropriately. |
| 657 | % |
| 658 | % (Having spent ages coming up with this cruft myself, I found some very |
| 659 | % similar, but slightly better, code in Appendix~D. So I've changed mine to |
| 660 | % match Donald's. Anyway, credit where it's due: cheers Don.) |
| 661 | % |
| 662 | % \begin{macrocode} |
| 663 | \newif\if@matched |
| 664 | \def\matcher#1#2#3{% |
| 665 | \expandafter\def\csname\string#1$match\endcsname##1#2##2##3\end{% |
| 666 | \ifx##2\relax% |
| 667 | \@matchedfalse% |
| 668 | \else% |
| 669 | \@matchedtrue% |
| 670 | \fi% |
| 671 | #3{##1}% |
| 672 | }% |
| 673 | \expandafter\def\expandafter#1\expandafter##\expandafter1\expandafter{% |
| 674 | \csname\string#1$match\endcsname##1#2\relax\end% |
| 675 | }% |
| 676 | } |
| 677 | % \end{macrocode} |
| 678 | % |
| 679 | % \end{macro} |
| 680 | % |
| 681 | % \begin{macro}{\sv@stripspc} |
| 682 | % |
| 683 | % This macro strips any trailing glue in the current horizontal list. This |
| 684 | % is fairly simple, actually: we just loop while glue is the last item. It's |
| 685 | % slightly complicated by penalties which \TeX\ puts into the list between |
| 686 | % the glue items, but we just remove them too. |
| 687 | % |
| 688 | % \begin{macrocode} |
| 689 | \def\sv@stripspc{% |
| 690 | \unpenalty% |
| 691 | \ifdim\lastskip=\z@\else% |
| 692 | \unskip\expandafter\sv@stripspc% |
| 693 | \fi% |
| 694 | } |
| 695 | % \end{macrocode} |
| 696 | % |
| 697 | % \end{macro} |
| 698 | % |
| 699 | % \begin{macro}{\sv@percent} |
| 700 | % |
| 701 | % This macro strips a single leading percent character if there is one, and |
| 702 | % if the \env{doc} package is loaded. We store the possibly stripped text in |
| 703 | % |\@tempa|. |
| 704 | % |
| 705 | % \begin{macrocode} |
| 706 | \begingroup |
| 707 | \catcode`\%=12 |
| 708 | \gdef\sv@percent#1#2\relax |
| 709 | {\ifx\check@percent\@@undefined |
| 710 | \ifx#1\relax\def\@tempa{}\else |
| 711 | \def\@tempa{#1#2}\fi\else |
| 712 | \ifx#1\relax\def\@tempa{}\else |
| 713 | \ifx#1%\def\@tempa{#2}\else |
| 714 | \def\@tempa{#1#2}\fi\fi\fi} |
| 715 | \endgroup |
| 716 | % \end{macrocode} |
| 717 | % |
| 718 | % \end{macro} |
| 719 | % |
| 720 | % \begin{macro}{\@isspaces} |
| 721 | % |
| 722 | % We want to avoid writing the first and last lines of the environment to the |
| 723 | % file if there's nothing in them. To do this, we need to know whether a |
| 724 | % piece of text contains only space characters. This macro does this, in a |
| 725 | % rather nasty way. See the other macros below for details of how this |
| 726 | % works. |
| 727 | % |
| 728 | % We define |\sv@safespc| at the same time: this makes space active and |
| 729 | % expand to a space character which is not active. Neat, huh? |
| 730 | % |
| 731 | % \begin{macrocode} |
| 732 | \begingroup |
| 733 | \lccode`\~32 |
| 734 | \lccode`\!32 |
| 735 | \lowercase{% |
| 736 | \endgroup |
| 737 | \def\@isspaces#1{% |
| 738 | \ifx#1\relax% |
| 739 | \def\@tempb{\@tempswafalse}% |
| 740 | \else\ifx#1~% |
| 741 | \let\@tempb\@isspaces% |
| 742 | \else% |
| 743 | \def\@tempb##1\relax{}% |
| 744 | \fi\fi% |
| 745 | \@tempb% |
| 746 | } |
| 747 | \def\sv@safespc{% |
| 748 | \catcode32\active% |
| 749 | \def~{ }% |
| 750 | } |
| 751 | } |
| 752 | % \end{macrocode} |
| 753 | % |
| 754 | % \end{macro} |
| 755 | % |
| 756 | % \begin{macro}{\sv@read} |
| 757 | % |
| 758 | % This macro does the main job of reading a chunk of verbatim text. You call |
| 759 | % it like this: |
| 760 | % |
| 761 | % \begin{quote} |
| 762 | % \syntax{"\\sv@read{"<end-text>"}{"<process-line-proc>"}{"<end-proc>"}"} |
| 763 | % \end{quote} |
| 764 | % |
| 765 | % The \synt{end-text} is the text to find at the end of the `environment': we |
| 766 | % stop when we find it. |
| 767 | % |
| 768 | % The \synt{process-line-proc} is a macro which is passed as an argument each |
| 769 | % line which we read from the text. |
| 770 | % |
| 771 | % The \synt{end-proc} is a macro to call once we've finished reading all of |
| 772 | % the text. This can tidy up an environment or close a file or whatever. |
| 773 | % |
| 774 | % We read the text by picking out newlines using a delimited macro. We have |
| 775 | % to be a little clever, because newlines are active in verbatim text. |
| 776 | % |
| 777 | % We will also strip `|%|' signs off the beginning if the \package{doc} |
| 778 | % package is here (\package{doc} tries to play with \LaTeX's verbatim stuff, |
| 779 | % and doesn't understand the way we do things). |
| 780 | % |
| 781 | % \begin{macrocode} |
| 782 | \def\sv@read#1#2#3{% |
| 783 | % \end{macrocode} |
| 784 | % |
| 785 | % This code does all sorts of evil things, so I'll start by opening a group. |
| 786 | % |
| 787 | % \begin{macrocode} |
| 788 | \begingroup% |
| 789 | % \end{macrocode} |
| 790 | % |
| 791 | % So that I can spot the end-text, I'll create a matcher macro. |
| 792 | % |
| 793 | % \begin{macrocode} |
| 794 | \matcher\@match{#1}\sv@read@ii% |
| 795 | % \end{macrocode} |
| 796 | % |
| 797 | % So that I can identify line ends, I'll make them active. I'll also make |
| 798 | % spaces active so that they can expand to whatever they ought to expand |
| 799 | % to (spaces in files, or funny \verb*" " characters or whatever. |
| 800 | % |
| 801 | % \begin{macrocode} |
| 802 | \catcode13\active% |
| 803 | \catcode32\active% |
| 804 | % \end{macrocode} |
| 805 | % |
| 806 | % I'll use the |\if@tempswa| flag to tell me whether I ought to output the |
| 807 | % current line. This is a little messy, so I'll describe it later. I'll |
| 808 | % initialise it to false because this is the correct thing to do. |
| 809 | % |
| 810 | % \begin{macrocode} |
| 811 | \@tempswafalse% |
| 812 | % \end{macrocode} |
| 813 | % |
| 814 | % Most of the job is done by two submacros. I'll define them in terms of |
| 815 | % my current arguments (to save lots of token munging). The first just |
| 816 | % extracts the next line (which ends at the next newline character) and |
| 817 | % tries to match it. |
| 818 | % |
| 819 | % \begin{macrocode} |
| 820 | \lccode`\~13\lowercase{% |
| 821 | \def\sv@read@i##1~{\@match{##1}}% |
| 822 | }% |
| 823 | % \end{macrocode} |
| 824 | % |
| 825 | % The results of the match get passed here, along with the text of the |
| 826 | % line up to the matched text. |
| 827 | % |
| 828 | % \begin{macrocode} |
| 829 | \def\sv@read@ii##1{% |
| 830 | % \end{macrocode} |
| 831 | % |
| 832 | % The first job to do is to maybe strip off percent signs from the beginning, |
| 833 | % to keep \package{doc} happy. |
| 834 | % |
| 835 | % \begin{macrocode} |
| 836 | \sv@percent##1\relax\relax% |
| 837 | % \end{macrocode} |
| 838 | % |
| 839 | % Now I need to decide whether I ought to output this line. The method goes |
| 840 | % like this: if this is the first line (|\if@tempswa| is false) or the last |
| 841 | % (|\if@matched| is true), \emph{and} the text consists only of spaces, then |
| 842 | % I'll ignore it. |
| 843 | % |
| 844 | % The first thing to do is to notice the last line -- if |\if@matched| is |
| 845 | % true, then I'll make |\if@tempswa| false to make the first-line and |
| 846 | % last-line cases work the same way. |
| 847 | % |
| 848 | % \begin{macrocode} |
| 849 | \if@matched\@tempswafalse\fi% |
| 850 | % \end{macrocode} |
| 851 | % |
| 852 | % Now if this is the first or last line, I'll examine it for spaces. This |
| 853 | % is done in a separate macro. It will set |\if@tempswa| false if the |
| 854 | % text contains only spaces. |
| 855 | % |
| 856 | % \begin{macrocode} |
| 857 | \if@tempswa\else\@tempswatrue\expandafter\@isspaces\@tempa\relax\fi% |
| 858 | % \end{macrocode} |
| 859 | % |
| 860 | % Now, if |\if@tempswa| is still true, perform the \<process-line-proc> on |
| 861 | % the line of text. I'll provide a group, so that it doesn't upset me |
| 862 | % too much. |
| 863 | % |
| 864 | % \begin{macrocode} |
| 865 | \if@tempswa% |
| 866 | \begingroup% |
| 867 | \expandafter#2\expandafter{\@tempa}% |
| 868 | \endgroup% |
| 869 | \fi% |
| 870 | % \end{macrocode} |
| 871 | % |
| 872 | % The next line won't be the first one, so I'll set the flag true in |
| 873 | % readiness. |
| 874 | % |
| 875 | % \begin{macrocode} |
| 876 | \@tempswatrue% |
| 877 | % \end{macrocode} |
| 878 | % |
| 879 | % Now, if that wasn't the last line, go round again; otherwise end the group |
| 880 | % I started ages ago, and do the user's \<end-proc>. |
| 881 | % |
| 882 | % \begin{macrocode} |
| 883 | \if@matched\def\@tempa{\endgroup#3}\else\let\@tempa\sv@read@i\fi% |
| 884 | \@tempa% |
| 885 | }% |
| 886 | % \end{macrocode} |
| 887 | % |
| 888 | % Now to start the thing up. I'll read the first line. |
| 889 | % |
| 890 | % \begin{macrocode} |
| 891 | \sv@read@i% |
| 892 | } |
| 893 | % \end{macrocode} |
| 894 | % |
| 895 | % \end{macro} |
| 896 | % |
| 897 | % \begin{macro}{\sv@readenv} |
| 898 | % |
| 899 | % This macro works out an appropriate end-text for the current environment. |
| 900 | % If you say \syntax{"\\sv@readenv{"<macro-name>"}"}, it will expand do |
| 901 | % \begin{listinglist} \listingsize \synshorts |
| 902 | % <macro-name>"{\\"$_{12}$"end{"$_{12}$<current-env-name>"}"$_{12}$"}"^^A |
| 903 | % "{\\end{"<current-env-name>"}}" |
| 904 | % \end{listinglist} |
| 905 | % Easy, no? |
| 906 | % |
| 907 | % This is all done with mirrors. No, err\dots\ it's done with |
| 908 | % |\expandafter|. |
| 909 | % |
| 910 | % \begin{macrocode} |
| 911 | \begingroup |
| 912 | \lccode`\<=`\{ |
| 913 | \lccode`\>=`\} |
| 914 | \lccode`\|=`\\ |
| 915 | \lowercase{\endgroup |
| 916 | \def\sv@readenv#1{\expandafter\sv@readenv@i\expandafter{\@currenvir}{#1}} |
| 917 | \def\sv@readenv@i#1#2{#2{|end<#1>}{\end{#1}}} |
| 918 | } |
| 919 | % \end{macrocode} |
| 920 | % |
| 921 | % \end{macro} |
| 922 | % |
| 923 | % \begin{macro}{\sv@verbline} |
| 924 | % |
| 925 | % This macro typesets a line in a verbatim way, so you can construct a real |
| 926 | % verbatim environment from it. It's a bit tricky in the way that it catches |
| 927 | % the last line. Don't worry about this: it's easy really. Note the |
| 928 | % |\relax| after the |\par| -- this is because \package{doc} tries to do |
| 929 | % clever things with |\par| to strip `|%|' signs out. |
| 930 | % |
| 931 | % \begin{macrocode} |
| 932 | \def\sv@verbline#1{% |
| 933 | \sv@emptybox\tw@% |
| 934 | \setbox\z@\hbox{#1\sv@stripspc}% |
| 935 | \sv@addtobox\tw@\z@% |
| 936 | \if1\ifdim\wd\tw@=\z@\if@matched0\else1\fi\else1\fi% |
| 937 | \svline\tw@\relax% |
| 938 | \fi% |
| 939 | } |
| 940 | % \end{macrocode} |
| 941 | % |
| 942 | % \end{macro} |
| 943 | % |
| 944 | % \subsection{Listing environments} |
| 945 | % |
| 946 | % The \env{listing} environment is our equivalent of the standard |
| 947 | % \env{verbatim} environment. We do some slightly cleverer things, though, |
| 948 | % to make sure (for example) that even text which contains |\end{listing}| |
| 949 | % can be typeset. |
| 950 | % |
| 951 | % \begin{macro}{\listinghook} |
| 952 | % |
| 953 | % Set everything up as required. This is here for customization. The |
| 954 | % underlying machinery doesn't mess with this directly, but assumes that |
| 955 | % |\svline| and |\svafter| are set up appropriately. |
| 956 | % |
| 957 | % \begin{macrocode} |
| 958 | \def\listinghook{% |
| 959 | \par% |
| 960 | \begingroup |
| 961 | \listinglist% |
| 962 | \listingsize% |
| 963 | \let\svline\listingline% |
| 964 | \def\svafter{\endlistinglist\endgroup}% |
| 965 | } |
| 966 | % \end{macrocode} |
| 967 | % |
| 968 | % \end{macro} |
| 969 | % |
| 970 | % \begin{macro}{\listinglist} |
| 971 | % \begin{environment}{listinglist} |
| 972 | % |
| 973 | % This defines the layout for the \env{listing} environment. It starts a |
| 974 | % list with the appropriate shape. It's also made into an environment, so |
| 975 | % that the end-paragraph-environment bits work correctly. |
| 976 | % |
| 977 | % The |\listingindent| length parameter sets up the indentation of the |
| 978 | % listings. If there's a |\parindent| setting, I'll line listings up with |
| 979 | % that; otherwise I'll just choose something which looks right. |
| 980 | % |
| 981 | % \begin{macrocode} |
| 982 | \newdimen\listingindent |
| 983 | \AtBeginDocument{% |
| 984 | \ifdim\parindent=\z@\listingindent1em\else\listingindent\parindent\fi% |
| 985 | } |
| 986 | % \end{macrocode} |
| 987 | % |
| 988 | % Now to define a size hook for the environment. This is fairly simple |
| 989 | % stuff. |
| 990 | % |
| 991 | % \begin{macrocode} |
| 992 | \ifx\listingsize\@@undefined |
| 993 | \let\listingsize\footnotesize |
| 994 | \fi |
| 995 | % \end{macrocode} |
| 996 | % |
| 997 | % Now to define the environment itself. Suppress the indentation if we're |
| 998 | % first thing on a new list item, so that the listing lines up with |
| 999 | % everything else. |
| 1000 | % |
| 1001 | % \begin{macrocode} |
| 1002 | \def\listinglist{% |
| 1003 | \list{}{% |
| 1004 | \if@inlabel% |
| 1005 | \leftmargin\z@% |
| 1006 | \else% |
| 1007 | \leftmargin\listingindent% |
| 1008 | \fi% |
| 1009 | \rightmargin\z@% |
| 1010 | \labelwidth\z@% |
| 1011 | \labelsep\z@% |
| 1012 | \itemindent\z@% |
| 1013 | \listparindent\z@% |
| 1014 | \let\makelabel\relax% |
| 1015 | \parsep\z@skip% |
| 1016 | }% |
| 1017 | \parfillskip\@flushglue% |
| 1018 | \item\relax% |
| 1019 | } |
| 1020 | \let\endlistinglist\endlist |
| 1021 | % \end{macrocode} |
| 1022 | % |
| 1023 | % \end{environment} |
| 1024 | % \end{macro} |
| 1025 | % |
| 1026 | % \begin{macro}{\svline} |
| 1027 | % \begin{macro}{\svdoline} |
| 1028 | % \begin{macro}{\listingline} |
| 1029 | % |
| 1030 | % The simple spit-out-a-line macro. |
| 1031 | % |
| 1032 | % \begin{macrocode} |
| 1033 | \def\svdoline#1{\leavevmode\box#1\par} |
| 1034 | \let\svline\svdoline |
| 1035 | \let\listingline\svline |
| 1036 | % \end{macrocode} |
| 1037 | % |
| 1038 | % \end{macro} |
| 1039 | % \end{macro} |
| 1040 | % \end{macro} |
| 1041 | % |
| 1042 | % \begin{macro}{\svafter} |
| 1043 | % |
| 1044 | % This is called when the machinery finishes. A default is set for safety's |
| 1045 | % sake. |
| 1046 | % |
| 1047 | % \begin{macrocode} |
| 1048 | \let\svafter\relax |
| 1049 | % \end{macrocode} |
| 1050 | % |
| 1051 | % \end{macro} |
| 1052 | % |
| 1053 | % \begin{environment}{listing} |
| 1054 | % |
| 1055 | % The \env{listing} environment is the only real verbatim-like environment we |
| 1056 | % create will all this kit, although it does the job very nicely. |
| 1057 | % |
| 1058 | % The environment indents its contents slightly, unlike \env{verbatim}, and |
| 1059 | % uses a smaller typeface in an attempt to fit 77-column text on an A5~page. |
| 1060 | % There is also a $*$-variant, which allows you to specify the terminating |
| 1061 | % text. This enables you to include absolutely any text in the environment, |
| 1062 | % including |\end{listing}|. |
| 1063 | % |
| 1064 | % First, we must define the |\listing| command. |
| 1065 | % |
| 1066 | % \begin{macrocode} |
| 1067 | \def\listing{\listinghook\sv@readenv\sv@listing} |
| 1068 | % \end{macrocode} |
| 1069 | % |
| 1070 | % Now we define the |\@listing| command, which does most of the work. We |
| 1071 | % base the \env{listing} environment on a \env{list}. |
| 1072 | % |
| 1073 | % \begin{macrocode} |
| 1074 | \def\sv@listing#1#2{\sv@startlisting\sv@read{#1}\sv@verbline{\svafter#2}} |
| 1075 | % \end{macrocode} |
| 1076 | % |
| 1077 | % Now we define the starred version. The command name needs to include the |
| 1078 | % `|*|' character, so we must use |\csname|. There's some hacking here to |
| 1079 | % allow us to read the name using the appropriate catcodes for otherwise |
| 1080 | % normal characters: \LaTeX\ activates some characters and makes them typeset |
| 1081 | % themselves to suppress some ligaturing. |
| 1082 | % |
| 1083 | % \begin{macrocode} |
| 1084 | \expandafter\def\csname listing*\endcsname{% |
| 1085 | \listinghook\begingroup\@noligs\listing@star% |
| 1086 | } |
| 1087 | \def\listing@star#1{\endgroup\sv@listing{#1}{\end{listing*}}} |
| 1088 | % \end{macrocode} |
| 1089 | % |
| 1090 | % \end{environment} |
| 1091 | % |
| 1092 | % \begin{environment}{ignore} |
| 1093 | % |
| 1094 | % The \env{ignore} environment entirely ignores its contents. Anything at |
| 1095 | % all may be put into the environment: it is discarded utterly. |
| 1096 | % |
| 1097 | % We define some macros for defining ignoring environments, because this can |
| 1098 | % be useful for version control, possibly. |
| 1099 | % |
| 1100 | % \begin{macrocode} |
| 1101 | \def\sv@ignore#1#2{% |
| 1102 | \@bsphack% |
| 1103 | \let\do\@makeother\dospecials% |
| 1104 | \sv@read{#1}\@gobble{\@esphack#2}% |
| 1105 | } |
| 1106 | \def\ignore{\sv@readenv\sv@ignore} |
| 1107 | \def\ignoreenv#1{% |
| 1108 | \expandafter\let\csname #1\endcsname\ignore% |
| 1109 | } |
| 1110 | \def\unignoreenv#1{% |
| 1111 | \expandafter\def\csname #1\endcsname{\endgroup}% |
| 1112 | \expandafter\def\csname end#1\endcsname% |
| 1113 | {\begingroup\def\@currenvir{#1}}% |
| 1114 | } |
| 1115 | % \end{macrocode} |
| 1116 | % |
| 1117 | % \end{environment} |
| 1118 | % |
| 1119 | % \subsection{The \env{verbwrite} environment} |
| 1120 | % |
| 1121 | % The \env{verbwrite} environment allows text to be written to a file in a |
| 1122 | % verbatim way. Note that tab characters don't work, because \TeX\ refuses |
| 1123 | % to be nice. |
| 1124 | % |
| 1125 | % \begin{macro}{\sv@write} |
| 1126 | % |
| 1127 | % As seems to be traditional now, we first define a general hookable macro |
| 1128 | % which allows a caller to specify the end-text and what to do afterwards. |
| 1129 | % |
| 1130 | % \begin{macrocode} |
| 1131 | \newwrite\sv@writefile |
| 1132 | \def\sv@write#1#2{% |
| 1133 | \begingroup% |
| 1134 | \@bsphack% |
| 1135 | \let\do\@makeother\dospecials% |
| 1136 | \sv@safespc% |
| 1137 | \sv@read{#1}\sv@writeline{\sv@endwrite#2}% |
| 1138 | } |
| 1139 | \def\sv@writeline#1{% |
| 1140 | \immediate\write\sv@writefile{#1}% |
| 1141 | } |
| 1142 | \def\sv@endwrite{% |
| 1143 | \@esphack% |
| 1144 | \endgroup% |
| 1145 | } |
| 1146 | % \end{macrocode} |
| 1147 | % |
| 1148 | % \end{macro} |
| 1149 | % |
| 1150 | % \begin{environment}{verbwrite} |
| 1151 | % |
| 1152 | % Now we can define the actual environment. We define a $*$-variant which |
| 1153 | % allows the user to specify the end-text, just to make sure. |
| 1154 | % |
| 1155 | % \begin{macrocode} |
| 1156 | \def\verbwrite#1{% |
| 1157 | \immediate\openout\sv@writefile#1\relax% |
| 1158 | \sv@readenv\sv@write% |
| 1159 | } |
| 1160 | \def\endverbwrite{\immediate\closeout\sv@writefile} |
| 1161 | \expandafter\def\csname verbwrite*\endcsname#1#2{% |
| 1162 | \immediate\openout\sv@writefile#2\relax% |
| 1163 | \sv@write{#1}{\immediate\closeout\sv@writefile\end{verbwrite*}}% |
| 1164 | } |
| 1165 | % \end{macrocode} |
| 1166 | % |
| 1167 | % \end{environment} |
| 1168 | % |
| 1169 | % \subsection{The \env{demo} environment} |
| 1170 | % |
| 1171 | % By way of tying all of this together, I present an environment for |
| 1172 | % displaying demonstrations of \LaTeX\ markup. We read the contents of the |
| 1173 | % environment, write it to a temporary file, and read it back twice, |
| 1174 | % typesetting it the first time and displaying it verbatim the second time. |
| 1175 | % |
| 1176 | % \begin{macro}{\sv@demoname} |
| 1177 | % |
| 1178 | % This macro expands to the filename to use for the temporary data. To |
| 1179 | % allow the package documentation to demonstrate the \env{demo} environment |
| 1180 | % itself, we need to keep a nesting count. This avoids too much hackery, |
| 1181 | % which unfortunately appears to plague all of my \TeX\ code. |
| 1182 | % |
| 1183 | % \begin{macrocode} |
| 1184 | \newcount\sv@nestcount |
| 1185 | \def\sv@demoname{demo\number\sv@nestcount.tmp} |
| 1186 | % \end{macrocode} |
| 1187 | % |
| 1188 | % \end{macro} |
| 1189 | % |
| 1190 | % \begin{macro}{\sv@demo} |
| 1191 | % |
| 1192 | % As for listing, we do all the business through a private macro. This is |
| 1193 | % good because it means we can leave the main macro readable. The argument |
| 1194 | % is the end-text to spot. |
| 1195 | % |
| 1196 | % \begin{macrocode} |
| 1197 | \def\sv@demo#1#2{% |
| 1198 | \@ifnextchar[{\sv@demo@i{#1}{#2}}{\sv@demo@i{#1}{#2}[n]}% |
| 1199 | } |
| 1200 | \def\sv@demo@i#1#2[#3]#4{% |
| 1201 | \advance\sv@nestcount by\@ne% |
| 1202 | \immediate\openout\sv@writefile\sv@demoname\relax% |
| 1203 | \sv@write{#1}{% |
| 1204 | \immediate\closeout\sv@writefile% |
| 1205 | \sv@dodemo{#2}{#3}{#4}% |
| 1206 | }% |
| 1207 | } |
| 1208 | % \end{macrocode} |
| 1209 | % |
| 1210 | % \end{macro} |
| 1211 | % |
| 1212 | % \begin{environment}{demo} |
| 1213 | % |
| 1214 | % This is the real environment. We provide \env{demo$*$} too, to allow the |
| 1215 | % user to choose the end-text. |
| 1216 | % |
| 1217 | % \begin{macrocode} |
| 1218 | \def\demo{\let\@demohook\demohook\sv@readenv\sv@demo} |
| 1219 | \expandafter\def\csname demo*\endcsname#1% |
| 1220 | {\let\@demohook\demohook\sv@demo{#1}{\end{demo*}}} |
| 1221 | % \end{macrocode} |
| 1222 | % |
| 1223 | % \end{environment} |
| 1224 | % |
| 1225 | % \begin{macro}{\demohook} |
| 1226 | % |
| 1227 | % Like |\listinghook|. So much so that we just call it, but first ensure |
| 1228 | % that the indent is zero (otherwise it looks really odd!). |
| 1229 | % |
| 1230 | % \begin{macrocode} |
| 1231 | \def\demohook{\listingindent\z@\listinghook} |
| 1232 | % \end{macrocode} |
| 1233 | % |
| 1234 | % \end{macro} |
| 1235 | % |
| 1236 | % \begin{macro}{\sv@dodemo} |
| 1237 | % |
| 1238 | % First, let's define some common bits of code in the stuff below. The |
| 1239 | % minipages used to typeset the material has some clever stuff to avoid |
| 1240 | % strange spacing in the output. |
| 1241 | % |
| 1242 | % \begin{macrocode} |
| 1243 | \def\sv@demosmp{% |
| 1244 | \begin{minipage}[t]{\@tempdima}% |
| 1245 | \vskip8\p@% |
| 1246 | \hrule\@height\z@% |
| 1247 | \raggedright% |
| 1248 | \vbox\bgroup% |
| 1249 | } |
| 1250 | \def\sv@demoemp{% |
| 1251 | \par\unpenalty\unskip% |
| 1252 | \egroup% |
| 1253 | \vskip8\p@% |
| 1254 | \hrule\@height\z@% |
| 1255 | \end{minipage}% |
| 1256 | } |
| 1257 | % \end{macrocode} |
| 1258 | % |
| 1259 | % This is the macro which actually typesets the demonstration. |
| 1260 | % |
| 1261 | % \begin{macrocode} |
| 1262 | \def\sv@dodemo#1#2#3{% |
| 1263 | % \end{macrocode} |
| 1264 | % |
| 1265 | % Now work out some values. We set |\hsize| to the line width leaving 2\,em |
| 1266 | % of space on either side. The size of the minipages is calculated depending |
| 1267 | % on the shape of the demonstration. This is all fairly simple. |
| 1268 | % |
| 1269 | % \begin{macrocode} |
| 1270 | \begingroup% |
| 1271 | \@tempdima\linewidth% |
| 1272 | \advance\@tempdima-2em% |
| 1273 | \hsize\@tempdima% |
| 1274 | \if#2w% |
| 1275 | \advance\@tempdima-2em% |
| 1276 | \else% |
| 1277 | \advance\@tempdima-3em% |
| 1278 | \divide\@tempdima2% |
| 1279 | \fi% |
| 1280 | % \end{macrocode} |
| 1281 | % |
| 1282 | % Now we open a big vertical box, and put in a header to mark off the |
| 1283 | % demonstration. |
| 1284 | % |
| 1285 | % \begin{macrocode} |
| 1286 | \par% |
| 1287 | \setbox\z@\hbox{\strut\enspace#3\enspace\strut}% |
| 1288 | \@tempdimb.5\dp\z@% |
| 1289 | \advance\@tempdimb-.5\ht\z@% |
| 1290 | \ht\z@\@tempdimb\dp\z@\@tempdimb% |
| 1291 | \noindent\hskip1em\vtop{% |
| 1292 | \hb@xt@\hsize{% |
| 1293 | \hrulefill% |
| 1294 | \raise\@tempdimb\box\z@% |
| 1295 | \hrulefill% |
| 1296 | }% |
| 1297 | \nointerlineskip% |
| 1298 | \hb@xt@\hsize{\vrule\@height5\p@\hfil\vrule\@height5\p@}% |
| 1299 | \nointerlineskip% |
| 1300 | % \end{macrocode} |
| 1301 | % |
| 1302 | % Now we insert the output text in the first minipage. I'll force `|%|' |
| 1303 | % to be a comment character, in case something like \package{doc} has had its |
| 1304 | % wicked way. |
| 1305 | % |
| 1306 | % \begin{macrocode} |
| 1307 | \vskip-\parskip% |
| 1308 | \noindent\hbox{}\hskip1em% |
| 1309 | \sv@demosmp% |
| 1310 | \catcode`\%14\relax% |
| 1311 | \@input{\sv@demoname}% |
| 1312 | \sv@demoemp% |
| 1313 | % \end{macrocode} |
| 1314 | % |
| 1315 | % Insert some kind of separation between the two. In `wide' format, we start |
| 1316 | % a new line, and put a ruleoff between the two. In `narrow' format, we just |
| 1317 | % leave some space. |
| 1318 | % |
| 1319 | % \begin{macrocode} |
| 1320 | \if#2w% |
| 1321 | \vskip8\p@\hrule\vskip8\p@% |
| 1322 | \noindent\hbox{}% |
| 1323 | \fi% |
| 1324 | \hskip1em% |
| 1325 | % \end{macrocode} |
| 1326 | % |
| 1327 | % Now we put the verbatim copy of the text in the other minipage. |
| 1328 | % |
| 1329 | % \begin{macrocode} |
| 1330 | \sv@demosmp% |
| 1331 | \@demohook% |
| 1332 | \verbinput@\@input\sv@demoname% |
| 1333 | \sv@demoemp% |
| 1334 | \par% |
| 1335 | \nointerlineskip% |
| 1336 | \hb@xt@\hsize{\vrule\@height5\p@\hfil\vrule\@height5\p@}% |
| 1337 | \hrule% |
| 1338 | }% |
| 1339 | \endgroup% |
| 1340 | \par% |
| 1341 | \vskip\baselineskip% |
| 1342 | #1% |
| 1343 | } |
| 1344 | % \end{macrocode} |
| 1345 | % |
| 1346 | % \end{macro} |
| 1347 | % |
| 1348 | % \subsection{Loading the colour package} |
| 1349 | % |
| 1350 | % If requested, we load the \package{svcolour} package here. This ensures |
| 1351 | % that it can patch this code if it needs to. |
| 1352 | % |
| 1353 | % \begin{macrocode} |
| 1354 | \ifsv@colour |
| 1355 | \RequirePackage{svcolour} |
| 1356 | \fi |
| 1357 | % \end{macrocode} |
| 1358 | % |
| 1359 | % That's all there is. Have fun. |
| 1360 | % |
| 1361 | % \begin{macrocode} |
| 1362 | %</package> |
| 1363 | % \end{macrocode} |
| 1364 | % |
| 1365 | % \subsection{The \package{svcolour} package} |
| 1366 | % |
| 1367 | % This is in a separate package to avoid dragging in the \package{color} |
| 1368 | % package if it's unwanted. |
| 1369 | % |
| 1370 | % I prefer English spellings. Here's a trivial redirection for Americans. |
| 1371 | % |
| 1372 | % \begin{macrocode} |
| 1373 | %<*color> |
| 1374 | \DeclareOption*{\PassOptionsToPackage{\CurrentOption}{svcolour}} |
| 1375 | \ProcessOptions |
| 1376 | \RequirePackage{svcolour} |
| 1377 | %</color> |
| 1378 | % \end{macrocode} |
| 1379 | % |
| 1380 | % And now we can start the thing properly. |
| 1381 | % |
| 1382 | % \begin{macrocode} |
| 1383 | %<*colour> |
| 1384 | \RequirePackage{color} |
| 1385 | % \end{macrocode} |
| 1386 | % |
| 1387 | % \begin{macro}{\@snarfcolour} |
| 1388 | % |
| 1389 | % Reading a colour specification is something we'll need to do a few times, |
| 1390 | % so an abstraction is useful. Its single argument is a continuation to |
| 1391 | % which we pass a colour-spec acceptable to the |\color| command. (This is |
| 1392 | % the same code as found in the \package{mdwtab} package. Remember to keep |
| 1393 | % them in step.) |
| 1394 | % |
| 1395 | % \begin{macrocode} |
| 1396 | \def\@snarfcolour#1{% |
| 1397 | \@ifnextchar[{\@snarfcolour@i{#1}}{\@snarfcolour@ii{#1}{}}% |
| 1398 | } |
| 1399 | \def\@snarfcolour@i#1[#2]{\@snarfcolour@ii{#1}{[#2]}} |
| 1400 | \def\@snarfcolour@ii#1#2#3{#1{#2{#3}}} |
| 1401 | % \end{macrocode} |
| 1402 | % |
| 1403 | % \end{macro} |
| 1404 | % |
| 1405 | % \begin{macro}{\svcolourline} |
| 1406 | % \begin{macro}{\svcolorline} |
| 1407 | % |
| 1408 | % Snarf the option, and plot the coloured bar. Note the penalties which are |
| 1409 | % meant to stick the glue and leaders onto the colour specials. |
| 1410 | % |
| 1411 | % \begin{macrocode} |
| 1412 | \def\svcolourline{\@snarfcolour\svcl@i} |
| 1413 | \def\svcl@i#1#2{% |
| 1414 | \skip@\wd#2% |
| 1415 | \advance\skip@\parfillskip% |
| 1416 | \advance\skip@.2em% |
| 1417 | \strut% |
| 1418 | \kern.2em% |
| 1419 | \begingroup\color#1\nobreak\leaders\vrule\hskip\skip@\endgroup% |
| 1420 | \nobreak\hskip-\skip@% |
| 1421 | \kern.2em% |
| 1422 | \box#2% |
| 1423 | \nobreak\hskip-\rightskip\vadjust{}% |
| 1424 | \par% |
| 1425 | } |
| 1426 | \let\svcolorline\svcolourline |
| 1427 | % \end{macrocode} |
| 1428 | % |
| 1429 | % \end{macro} |
| 1430 | % \end{macro} |
| 1431 | % |
| 1432 | % Done! |
| 1433 | % |
| 1434 | % \begin{macrocode} |
| 1435 | %</colour> |
| 1436 | % \end{macrocode} |
| 1437 | % |
| 1438 | % \subsection{The \package{svsplit} package} |
| 1439 | % |
| 1440 | % \begin{macrocode} |
| 1441 | %<*split> |
| 1442 | \RequirePackage{sverb} |
| 1443 | % \end{macrocode} |
| 1444 | % |
| 1445 | % \begin{environment}{splitverb} |
| 1446 | % \begin{environment}{splitverb*} |
| 1447 | % |
| 1448 | % The basic environments are simple enough. |
| 1449 | % |
| 1450 | % \begin{macrocode} |
| 1451 | \def\splitverb{\listinghook\sv@readenv\splitverb@} |
| 1452 | \expandafter\def\csname splitverb*\endcsname% |
| 1453 | {\listinghook\begingroup\@noligs\svsplit@star} |
| 1454 | \def\svsplit@star#1{\endgroup\splitverb@{#1}{\end{splitverb*}}} |
| 1455 | % \end{macrocode} |
| 1456 | % |
| 1457 | % \end{environment} |
| 1458 | % \end{environment} |
| 1459 | % |
| 1460 | % \begin{macro}{\splitverb@} |
| 1461 | % |
| 1462 | % Even this isn't so bad, really. |
| 1463 | % |
| 1464 | % \begin{macrocode} |
| 1465 | \def\splitverb@#1#2{\sv@startlisting\sv@read{#1}\svsplit@line{\svafter#2}} |
| 1466 | % \end{macrocode} |
| 1467 | % |
| 1468 | % \end{macro} |
| 1469 | % |
| 1470 | % \begin{macro}{\svsplit@line} |
| 1471 | % |
| 1472 | % For the sake of readability (and maybe saving a few tokens), we define some |
| 1473 | % synonyms for \TeX's scratch registers. |\svsplit@remain| will be a |
| 1474 | % |\global| register containing the remaining horizontal space on the line; |
| 1475 | % |\svsplit@indent| is a local register containing the amount of initial |
| 1476 | % whitespace on the line. |
| 1477 | % |
| 1478 | % \begin{macrocode} |
| 1479 | \dimendef\svsplit@remain=1 |
| 1480 | \dimendef\svsplit@indent=2 |
| 1481 | % \end{macrocode} |
| 1482 | % |
| 1483 | % The switch |\svsplit@| is set if we've found a good place to split the |
| 1484 | % current line. |
| 1485 | % |
| 1486 | % \begin{macrocode} |
| 1487 | \newif\ifsvsplit@ |
| 1488 | % \end{macrocode} |
| 1489 | % |
| 1490 | % And finally a delimiter. This is the same one I use everywhere else. |
| 1491 | % |
| 1492 | % \begin{macrocode} |
| 1493 | \def\q@delim{\q@delim} |
| 1494 | % \end{macrocode} |
| 1495 | % |
| 1496 | % \begin{macrocode} |
| 1497 | \begingroup |
| 1498 | \catcode`\~=\active \lccode`\~=32 |
| 1499 | \catcode`\!=\active \lccode`\!=9 |
| 1500 | \lowercase{\endgroup |
| 1501 | % \end{macrocode} |
| 1502 | % |
| 1503 | % So far, so good. The |\svsplit@line| macro is given a line of text. We |
| 1504 | % initialize |\svtab| to be a \emph{single} space, |\svsplit@remain| to be |
| 1505 | % the text width, and |\svsplit@indent| to zero. Then we embark on the first |
| 1506 | % loop, which attempts to find the width of the leading whitespace. |
| 1507 | % |
| 1508 | % \begin{macrocode} |
| 1509 | \def\svsplit@line#1{% |
| 1510 | \divide\svtab8% |
| 1511 | \global\svsplit@remain\linewidth% |
| 1512 | \svsplit@indent\z@% |
| 1513 | \sv@emptybox\tw@% |
| 1514 | \let\next@\svsplit@findindent% |
| 1515 | \next@#1\q@delim% |
| 1516 | } |
| 1517 | % \end{macrocode} |
| 1518 | % |
| 1519 | % A straightforward tail-recursive loop finds out how much whitespace there |
| 1520 | % is at the start of the current line. Note that |\next@| is already set up |
| 1521 | % for the optimized case of continuing the loop. Also, if we reach the end |
| 1522 | % then this is a blank line, so only emit something if we didn't see the |
| 1523 | % end-marker. This is the only place we need to check for this. |
| 1524 | % |
| 1525 | % \begin{macrocode} |
| 1526 | \def\svsplit@findindent#1{% |
| 1527 | \ifx~#1% |
| 1528 | \advance\svsplit@indent\svtab% |
| 1529 | \else\ifx!#1% |
| 1530 | \dimen@8\svtab% |
| 1531 | \divide\svsplit@indent\dimen@% |
| 1532 | \multiply\svsplit@indent\dimen@% |
| 1533 | \advance\svsplit@indent\dimen@% |
| 1534 | \else\ifx\q@delim#1% |
| 1535 | \if@matched\else\svline\tw@\fi% |
| 1536 | \let\next@\relax% |
| 1537 | \else% |
| 1538 | \def\next@{\svsplit@scanline{#1}}% |
| 1539 | \fi\fi\fi% |
| 1540 | \next@% |
| 1541 | } |
| 1542 | % \end{macrocode} |
| 1543 | % |
| 1544 | % Now we have to actually scan the line to find breakpoints. We build the |
| 1545 | % current unbreakable chunk in |\box|~0. When we find a breakpoint, we close |
| 1546 | % the box, maybe stretch it to take into account trailing space, and attach |
| 1547 | % it to |\box|~2, which is gathering the current line. If |\svsplit@remain| |
| 1548 | % hits zero then we flush |\box|~2 to the output and continue on the next |
| 1549 | % line with a (more-or-less) clean slate. |
| 1550 | % |
| 1551 | % If there's no breakpoint then we're hosed. In that case, we just insert a |
| 1552 | % (|\normalfont|) hyphen and eject what we've got. |
| 1553 | % |
| 1554 | % Note that this assumes that the indentation will fit. If not, then we're |
| 1555 | % deeply stuffed. |
| 1556 | % |
| 1557 | % \begin{macrocode} |
| 1558 | \def\svsplit@scanline{% |
| 1559 | \svsplit@false% |
| 1560 | \let\next@\svsplit@char% |
| 1561 | \setbox\z@\hbox\bgroup% |
| 1562 | \kern\svsplit@indent% |
| 1563 | \global\advance\svsplit@remain-\svsplit@indent% |
| 1564 | \next@% |
| 1565 | } |
| 1566 | % \end{macrocode} |
| 1567 | % |
| 1568 | % Scanning a character isn't so bad, if we take it a step at a time. |
| 1569 | % |
| 1570 | % \begin{macrocode} |
| 1571 | \def\svsplit@char#1{% |
| 1572 | % \end{macrocode} |
| 1573 | % |
| 1574 | % If the character is a space or a tab, then we call |\svsplit@space| which |
| 1575 | % knows about adding breakable whitespace. For tabs, this involves computing |
| 1576 | % the correct tab size. |
| 1577 | % |
| 1578 | % \begin{macrocode} |
| 1579 | \ifx~#1% |
| 1580 | \svsplit@space\svtab% |
| 1581 | \else\ifx!#1% |
| 1582 | \@tempdima\linewidth% |
| 1583 | \advance\@tempdima-\svsplit@remain% |
| 1584 | \@tempdimb\@tempdima% |
| 1585 | \dimen@8\svtab% |
| 1586 | \divide\@tempdimb\dimen@% |
| 1587 | \multiply\@tempdimb\dimen@% |
| 1588 | \advance\@tempdimb\dimen@% |
| 1589 | \advance\@tempdimb-\@tempdima% |
| 1590 | \svsplit@space\@tempdimb% |
| 1591 | % \end{macrocode} |
| 1592 | % |
| 1593 | % We might have reached the end of the line. If so, then we finish off. |
| 1594 | % |
| 1595 | % \begin{macrocode} |
| 1596 | \else\ifx\q@delim#1% |
| 1597 | \let\next@\svsplit@done% |
| 1598 | % \end{macrocode} |
| 1599 | % |
| 1600 | % Otherwise it's a normal character. If there's not enough space then force |
| 1601 | % a break. |
| 1602 | % |
| 1603 | % \begin{macrocode} |
| 1604 | \else% |
| 1605 | \ifdim\svsplit@remain<2\svtab% |
| 1606 | \ifsvsplit@\else\normalfont-\svsplit@break\fi% |
| 1607 | \svsplit@eject% |
| 1608 | \fi% |
| 1609 | % \end{macrocode} |
| 1610 | % |
| 1611 | % Insert the character and decrement the distance-left register. |
| 1612 | % |
| 1613 | % \begin{macrocode} |
| 1614 | #1% |
| 1615 | \global\advance\svsplit@remain-\svtab% |
| 1616 | % \end{macrocode} |
| 1617 | % |
| 1618 | % Now we see if it's a breakable-after character and if so mark it as being |
| 1619 | % breakable. |
| 1620 | % |
| 1621 | % \begin{macrocode} |
| 1622 | \def\temp@##1#1##2\q@delim% |
| 1623 | {\ifx\q@delim##2\q@delim\else\svsplit@break\fi}% |
| 1624 | \expandafter\temp@\svsplitchars#1\q@delim% |
| 1625 | % \end{macrocode} |
| 1626 | % |
| 1627 | % And with that, we're done. |
| 1628 | % |
| 1629 | % \begin{macrocode} |
| 1630 | \fi\fi\fi% |
| 1631 | \next@% |
| 1632 | } |
| 1633 | % \end{macrocode} |
| 1634 | % |
| 1635 | % Our next macro is the break-insertion subroutine, which is quite easy. |
| 1636 | % |
| 1637 | % \begin{macrocode} |
| 1638 | \def\svsplit@break{% |
| 1639 | \egroup% |
| 1640 | \sv@addtobox\tw@\z@% |
| 1641 | \svsplit@true% |
| 1642 | \setbox\z@\hbox\bgroup% |
| 1643 | } |
| 1644 | % \end{macrocode} |
| 1645 | % |
| 1646 | % Now we add space to the current box. The argument is a dimen register. |
| 1647 | % |
| 1648 | % \begin{macrocode} |
| 1649 | \def\svsplit@space#1{% |
| 1650 | \ifdim\svsplit@remain>#1\kern#1\global\advance\svsplit@remain-#1\fi% |
| 1651 | \svsplit@break% |
| 1652 | \ifdim\svsplit@remain>#1\else\svsplit@eject\fi% |
| 1653 | } |
| 1654 | % \end{macrocode} |
| 1655 | % |
| 1656 | % We now come to a slightly involved piece of code, which is how to flush out |
| 1657 | % a line, and then fix up the registers for the next line correctly. |
| 1658 | % |
| 1659 | % \begin{macrocode} |
| 1660 | \def\svsplit@eject{% |
| 1661 | \egroup% |
| 1662 | \svline\tw@% |
| 1663 | \sv@emptybox\tw@% |
| 1664 | \svsplit@false% |
| 1665 | \setbox\z@\hbox\bgroup% |
| 1666 | \kern\svsplit@indent% |
| 1667 | \global\svsplit@remain\linewidth% |
| 1668 | \global\advance\svsplit@remain-\svsplit@indent% |
| 1669 | \global\advance\svsplit@remain-\wd\z@% |
| 1670 | \unhbox\z@% |
| 1671 | } |
| 1672 | % \end{macrocode} |
| 1673 | % |
| 1674 | % Finally, how to finish the line and go home. |
| 1675 | % |
| 1676 | % \begin{macrocode} |
| 1677 | \def\svsplit@done{% |
| 1678 | \egroup% |
| 1679 | \sv@addtobox\tw@\z@% |
| 1680 | \svline\tw@% |
| 1681 | } |
| 1682 | % \end{macrocode} |
| 1683 | % |
| 1684 | % End the |\lowercase| hack. |
| 1685 | % |
| 1686 | % \begin{macrocode} |
| 1687 | } |
| 1688 | % \end{macrocode} |
| 1689 | % |
| 1690 | % \end{macro} |
| 1691 | % |
| 1692 | % Finally, set the breakable characters to something plausible. |
| 1693 | % |
| 1694 | % \begin{macrocode} |
| 1695 | \def\svsplitchars{:/.} |
| 1696 | % \end{macrocode} |
| 1697 | % |
| 1698 | % And with that, we're done! |
| 1699 | % |
| 1700 | % \begin{macrocode} |
| 1701 | %</split> |
| 1702 | % \end{macrocode} |
| 1703 | % |
| 1704 | % \hfill Mark Wooding, \today |
| 1705 | % |
| 1706 | % \Finale |
| 1707 | % |
| 1708 | \endinput |