3 % $Id: cmtt.dtx,v 1.1 2002/02/03 20:49:02 mdw Exp $
5 % Nicer handling of the Computer Modern Typewriter font
7 % (c) 1996 Mark Wooding
9 %----- Revision history -----------------------------------------------------
12 % Revision 1.1 2002/02/03 20:49:02 mdw
13 % Checkin for new build system.
15 % Revision 1.1 1996/11/19 20:47:55 mdw
21 % \begin{meta-comment} <general public licence>
23 %% mdwlist package -- various list-related things
24 %% Copyright (c) 1996 Mark Wooding
26 %% This program is free software; you can redistribute it and/or modify
27 %% it under the terms of the GNU General Public License as published by
28 %% the Free Software Foundation; either version 2 of the License, or
29 %% (at your option) any later version.
31 %% This program is distributed in the hope that it will be useful,
32 %% but WITHOUT ANY WARRANTY; without even the implied warranty of
33 %% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
34 %% GNU General Public License for more details.
36 %% You should have received a copy of the GNU General Public License
37 %% along with this program; if not, write to the Free Software
38 %% Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
43 % \begin{meta-comment} <Package preambles>
44 %<+sty>\NeedsTeXFormat{LaTeX2e}
45 %<+sty>\ProvidesPackage{cmtt}
46 %<+fd>\ProvidesFile{mTTcmtt.fd}
47 %<+def>\ProvidesFile{mTTcmtt.def}
48 %<+sty|fd|def> [1996/05/25 1.1 Handing of the cmtt font]
53 %% {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
54 %% 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
55 %% Digits \0\1\2\3\4\5\6\7\8\9
56 %% Exclamation \! Double quote \" Hash (number) \#
57 %% Dollar \$ Percent \% Ampersand \&
58 %% Acute accent \' Left paren \( Right paren \)
59 %% Asterisk \* Plus \+ Comma \,
60 %% Minus \- Point \. Solidus \/
61 %% Colon \: Semicolon \; Less than \<
62 %% Equals \= Greater than \> Question mark \?
63 %% Commercial at \@ Left bracket \[ Backslash \\
64 %% Right bracket \] Circumflex \^ Underscore \_
65 %% Grave accent \` Left brace \{ Vertical bar \|
66 %% Right brace \} Tilde \~}
69 % \begin{meta-comment}
73 \describespackage{cmtt}
79 %^^A-------------------------------------------------------------------------
80 % \section{Introductory note}
82 % \LaTeX\ has a rather cunning encoding handling system, which makes funny
83 % commands like accents work properly independent of the current font's
84 % actual layout. While this works rather well most of the time, the standard
85 % \mtt{tt} font has been rather left out of things. \LaTeX\ assumes that
86 % the Computer Modern Typewriter fonts have exactly the same layout as the
87 % more normal Computer Modern Roman family (i.e., that both conform to the
88 % \mtt{OT1} encoding). This plainly isn't true, since the Typewriter font
89 % contains a bunch of standard ASCII characters which are omitted from the
90 % standard Computer Modern fonts, such as curly braces \mtt{\{} and \mtt{\}},
91 % and the backslash \mtt{\\}; these are usually dug up from the maths fonts,
92 % which looks fine in normal text, but looks really odd in monospace text.
93 % Compare `\texttt{\textbackslash begin\{document\}}' to
94 % `\mtt{\\begin\{document\}}', for example.
96 % There are two possibilities for dealing with this problem. One is to use
97 % the \mtt{\\verb} command, which works since all the extra characters in
98 % the Typewriter font are in the correct places, or use the DC~fonts, which
99 % have a proper encoding set up which contains all of these special
102 % Neither of these solutions is perfect. Using \mtt{\\verb} causes all
103 % manner of little niggly problems: you can't use it in footnotes or
104 % section headings, for example. (There are of course workarounds for this
105 % sort of thing: the author's \package{footnote} package provides a
106 % \env{footnote} environment which will allow verbatim text, and verbatim
107 % text in section headings can be achieved if one is sufficiently
108 % \TeX nical.) Using the DC~fonts is fine, although you actually lose a
109 % glyph or two. As far as the author is aware, the character \mtt{\'} (an
110 % `unsexed' single quote) is not present in the \mtt{T1}-encoded version of
111 % Computer Modern Typewriter, although it is hidden away in the original
112 % version. The author has found a need for this character in computer
113 % listings, and was horrified to discover that it was replaced by a German
114 % single quote character (\mtt{\\quotesinglbase}).
116 % This package defines a special encoding for the Computer Modern Typewriter
117 % font, so that documents can take advantage of its ASCII characters without
118 % resorting to verbatim text. (The main advantage of the DC~fonts, that
119 % words containing accents can be hyohenated, doesn't really apply to the
120 % Typewriter font, since it doesn't allow hyphenation by default anyway.)
122 % There are several files you'll need to create:
123 % \begin{description} \def\makelabel#1{\hskip\labelsep\mttfamily#1\hfil}
125 % \item [cmtt.sty] tells \LaTeX\ that there's a new encoding. It also
126 % provides some options for customising some aspects of the
127 % encoding, and defines some useful commands.
129 % \item [mTTenc.def] describes the encoding to \LaTeX: it sets up all the
130 % appropriate text commands so that they produce beautiful results.
132 % \item [mTTcmtt.fd] describes the re-encoded version of the font. This
133 % is more or less a copy of the file \mtt{OT1cmtt.fd}.
137 % The package accepts some options which may be useful:
138 % \begin{description} \def\makelabel#1{\hskip\labelsep\sffamily#1\hfil}
140 % \item [override] overrides the meaning of the \mtt{\\ttfamily} command
141 % (and therefore also the \mtt{\\texttt} command too), making it the
142 % same as the new \mtt{\\mttfamily} command. This isn't the default
143 % just in case the change breaks something in an unexpected way.
145 % \item [t1] informs the package that you're using the \mtt{T1} encoding,
146 % and therefore can borrow some accented characters from the DC~version
147 % of Computer Modern Typewriter. This will probably be unnecessary,
148 % since the package attempts to work out what to do all by itself.
150 % \item [ot1] forces the package \emph{not} to use the DC~version of the
151 % Computer Modern Typewriter font for funny accents. Only use this
152 % option if the package thinks it should use the DC~Typewriter font
157 % \DescribeMacro{\mttfamily}
158 % The command \mtt{\\mttfamily} selects the properly-encoded Typewriter
159 % font. It's a declaration which works just like the \mtt{\\ttfamily}
160 % command, except that comamnds like \mtt{\\\}} and \mtt{\\\_} use the
161 % characters from the font rather than choosing odd-looking versions from
162 % the maths fonts. All of the accent commands still work properly. In fact,
163 % some accent commands which didn't work before have been fixed. For
164 % example, saying `\mtt{\\texttt\{P\\'al Erd\\H os\}}' would produce
165 % something truly appalling like `\texttt{P\'al Erd\H os}', which is
166 % obviously ghastly. The new encoding handles this properly, and produces
167 % `\textmtt{P\'al Erd\H os}'.\footnote{
168 % This isn't quite perfect. The accent, which isn't actually present in
169 % the Typewriter font, is taken from the Computer Modern bold font, but
170 % it doesn't look too bad. However, if you pass the option \textsf{t1}
171 % to the \package{cmtt} package when you load it, the accent will be taken
172 % from the DC~Typewriter font, and it will look totally wonderful.}
174 % \DescribeMacro{\textmtt}
175 % Font changing commands are much more convenient than th declarations,
176 % so a command \mtt{\\textmtt} is provided: it just typesets its argument
177 % in the re-encoded Typewriter font.
179 % \DescribeMacro{\mtt}
180 % Rather more excitingly, the \mtt{\\mtt} command allows you to generate
181 % almost-verbatim text very easily, without any of the restrictions of
182 % the \mtt{\\verb} command. This command was inspired by something which
183 % David Carlisle said to me in an email correspondence regarding the
184 % overuse of verbatim commands.
186 % \mtt{\\mtt} redefines several `short' commands to typeset the obvious
187 % characters. The complete list is shown below: there are some oddities,
190 % ^^A This is an evil table. See if I care. (This is based on lots of
191 % ^^A hacking I did in glyphs.tex, but a good deal less horrible.)
194 % \hbox to \hsize\bgroup
198 % \mtt{\\\char`#2}\quad\hfil%
200 % \def\h{\noalign{\hrule}}
201 % \def\v{height2pt&\omit&&\omit&&\omit&&\omit&&\omit&\cr}
204 % \ialign\bgroup&\vrule#&\ex#\cr \h\v
205 % &~\\&&~\{&&~\}&&~\_&&~\^&\cr \v\h\v
206 % &~\$&&~\%&&~\&&&~\#&&~\~&\cr \v\h\v
207 % &~\"&&~\'&&~\ &&~\|&&\omit\hfil&\cr \v\h
212 % As well as redefining these commands, \mtt{\\mtt} will endeavour to make
213 % single special characters display themselves in a verbatim-like way. This
214 % only works on `active' characters (like \mtt{~}), and \mtt{\\mtt} makes
215 % no attempt to change the category codes of any characters.
217 % Among other things, you'll probably noticed that several accent-making
218 % commands have been redefined. You can still use these accents through
219 % the \mtt{\\a} command, by saying \mtt{\\a'}, \mtt{\\a\^} and so on,
220 % as in the \env{tabbing} environment.
222 % There are also some oddities in the table: \mtt{\|} and \mtt{\"} can be
223 % accessed easily without playing with silly commands. Well, that's almost
224 % the case: these two characters are both often used as `short' verbatim
225 % commands, so they are forced back to their normal meanings so you can
228 % Finally, a word on spacing. The \mtt{\\\ } command has been hijacked
229 % to produce a funny `visible space' character. You can still produce
230 % multiple spaces by saying something like `\mtt{\ \{\}\ \{\}}\dots\mtt{\ }',
231 % which is a bit contrived, but that's tough. Also, \mtt{~} has been stolen
232 % so that you can type \mtt{~} characters (e.g., in URLs), so the only
233 % way you can tpye a nonbreaking space is by using the \mtt{\\nobreakspace}
234 % command, which is a bit of a mouthful. There's an abbreviation, though:
235 % \mtt{\\nbsp} now means exactly the same thing.
237 % Was that not all supremely useful? Oh, just a note: this document doesn't
238 % use a single verbatim command or environment (except in the listings,
239 % where it's unavoidable) -- it's all done with \mtt{\\mtt}.
243 % \section{Implementation}
245 % \subsection{The package}
251 % I'll start with some options handling.
254 \newif\ifcmtt@override
255 \newif\ifcmtt@dcfonts
256 \def\@tempa{T1}\ifx\encodingdefault\@tempa
259 \DeclareOption{override}{\cmtt@overridetrue}
260 \DeclareOption{t1}{\cmtt@dcfontstrue}
261 \DeclareOption{ot1}{\cmtt@dcfontsfalse}
265 % This bit is really trivial. I'll just declare the font encoding. Oh, that
269 \DeclareFontEncoding{mTT}{}{}
272 % Wait: there's a problem. \LaTeX\ will now complain bitterly that it can't
273 % find the font \mtt{mTT/cmr/m/n}, which is readonable, since I haven't
274 % declared any such font. The following line should sort this out,
277 \DeclareFontSubstitution{mTT}{cmtt}{m}{n}
280 % Now I'd better load all the text commands I'll need when in this funny
287 % \begin{macro}{\mttfamily}
288 % \begin{macro}{\textmtt}
290 % Finally, I'll need to define a command which switches to this funny font,
291 % and a \mtt{\\text}\dots\ command for it.
294 \DeclareRobustCommand{\mttfamily}{%
295 \fontencoding{mTT}\fontfamily{\ttdefault}\selectfont%
297 \DeclareTextFontCommand{\textmtt}{\mttfamily}
303 % If an override was requested, make \mtt{\\ttfamily} the same as
308 \let\ttfamily\mttfamily
312 % Well, that's all that's needed for the font definition. Here's a command
313 % which will typeset its argument in the typewriter font, allowing easy
314 % access to all the funny characters, and printing them properly in the
315 % correct font (which \mtt{\\\{} doesn't do, for example).
317 % \begin{macro}{\mtt@setchar}
319 % This macro assigns the given meaning to the given control sequence. Also,
320 % if the character named in the control sequence is currently set active,
321 % it will set the active meaning of the character to the same value.
324 \def\mtt@setchar#1#2{%
325 \ifx#1#2\chardef#1`#1\else\let#1#2\fi%
326 \ifnum\catcode`#1=13%
329 \lowercase{\endgroup\let~#1}%
336 % \begin{macro}{\mtt@chars}
338 % This macro lists the various control sequences which should be set up,
339 % so that they can be easily added to.
348 \do\'\textquotesingl%
352 \do\_\textunderscore%
354 \do\}\textbraceright%
356 \do\ \textvisiblespace%
362 % \begin{macro}{\mtt@do}
364 % This just sets up all the special characters listed above. It's a simple
365 % abbreviation, really.
368 \def\mtt@do{\let\do\mtt@setchar\mtt@chars}
373 % \begin{macro}{\mtt}
375 % And finally, the macro itself. Ta-da!
378 \DeclareRobustCommand\mtt[1]{\textmtt{\mtt@do#1}}
383 % \begin{macro}{\@tabacckludge}
385 % The otherwise almost totally perfect \mtt{\\@tabacckludge} gets very
386 % upset when its argument is an active character. (If you're wondering,
387 % this is the command which is responsible for the behaviour of the \mtt{\\a}
388 % command.) Adding a \mtt{\\string} makes everything work perfectly.
391 \def\@tabacckludge#1{%
392 \expandafter\@changed@cmd\csname\string#1\endcsname\relax%
399 % \begin{macro}{\nbsp}
401 % Make an abbreviation for \mtt{\\nobreakspace}.
404 \let\nbsp\nobreakspace
409 % I think that's all that I have to do for the package. If there's any
410 % more to do, I'll add it later.
417 % \subsection{The font definition file}
419 % This is obviously copied almost verbatim from the file \mtt{OT1cmtt.fd}.
423 \DeclareFontFamily{mTT}{cmtt}{\hyphenchar\font\m@ne}
424 \DeclareFontShape{mTT}{cmtt}{m}{n}{
425 <5> <6> <7> <8> cmtt8
428 <12> <14.4> <17.28> <20.74> <24.88> cmtt12
430 \DeclareFontShape{mTT}{cmtt}{m}{it}{
431 <5> <6> <7> <8> <9> <10> <10.95> <12> <14.4> <17.28> <20.74> <24.88>
434 \DeclareFontShape{mTT}{cmtt}{m}{sl}{
435 <5> <6> <7> <8> <9> <10> <10.95> <12> <14.4> <17.28> <20.74> <24.88>
438 \DeclareFontShape{mTT}{cmtt}{m}{sc}{
439 <5> <6> <7> <8> <9> <10> <10.95> <12> <14.4> <17.28> <20.74> <24.88>
442 \DeclareFontShape{mTT}{cmtt}{m}{ui} {<->sub * cmtt/m/it} {}
443 \DeclareFontShape{mTT}{cmtt}{bx}{n} {<->sub * cmtt/m/n} {}
444 \DeclareFontShape{mTT}{cmtt}{bx}{it} {<->sub * cmtt/m/it} {}
445 \DeclareFontShape{mTT}{cmtt}{bx}{ui} {<->sub * cmtt/m/it} {}
450 % \subsection{The encoding definitions file}
452 % I've saved the trickiest bit until last. This file defines the mappings
453 % from text commands to glyphs in the font.
459 % First for some fun with accents. The |cmtt| font doesn't contain all of
460 % the accents which the other Computer Modern fonts do, because those slots
461 % contain the standard ASCII characters which usually have to be `borrowed'
462 % from the maths fonts.
464 % Anyway, there's a load which don't need any special treatment. These are
465 % chosen from the \mtt{OT1} encoding by default anyway, so I needn't
466 % bother unless I'm really bothered about speed. I'm not, so I'll save
469 % Following the example of the \TeX book, I'll use the bold roman font
470 % for accents, so that they don't look really spindly. This is actually
471 % remarkably difficult to do, because the \textsf{NFSS} keeps getting in
472 % the way. I'll look after the old font name in a macro (it's handy that
473 % \textsf{NFSS} maintains this for me) and change to a known font, do the
474 % accent, change font back again, do the argument to the accent, and then
475 % close the group I did all of this in, so that no-one else notices what a
476 % naughty chap I am, really. This is startlingly evil.
479 \def\cmtt@accent#1#2{{%
480 \let\@old@font\font@name%
482 \fontencoding{T1}\selectfont%
484 \usefont{OT1}{cmr}{bx}{n}%
490 % And now for the actual offending accents.
493 \DeclareTextCommand{\H}{mTT}{\cmtt@accent\H}
494 \DeclareTextCommand{\.}{mTT}{\cmtt@accent\.}
497 % The `under' accents are all OK, so I shan't bother to define them either.
498 % Similarly, lots of the text symbol commands are fine as they are by
499 % default and I don't need to try and define them again.
501 % This, then, is the remaining commands which really need sorting out.
502 % (By the way, the only reason I've redefined \mtt{\\textellipsis} is
503 % because otherwise it will mess up the nice monospacing.)
506 \DeclareTextSymbol{\textbackslash}{mTT}{92}
507 \DeclareTextSymbol{\textbar}{mTT}{124}
508 \DeclareTextSymbol{\textbraceleft}{mTT}{123}
509 \DeclareTextSymbol{\textbraceright}{mTT}{125}
510 \DeclareTextSymbol{\textless}{mTT}{60}
511 \DeclareTextSymbol{\textgreater}{mTT}{62}
512 \DeclareTextSymbol{\textunderscore}{mTT}{95}
513 \DeclareTextSymbol{\textvisiblespace}{mTT}{32}
514 \DeclareTextCommand{\textellipsis}{mTT}{...}
515 \DeclareTextSymbol{\textquotedbl}{mTT}{34}
516 \DeclareTextSymbol{\textquotesingl}{mTT}{13}
519 % That's all there is. Please return to your homes.