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1 | \C{input} Halibut input format |
2 | |
3 | This chapter describes the format in which you should write |
4 | documents to be processed by Halibut. |
5 | |
6 | \H{input-basics} The basics |
7 | |
8 | Halibut's input files mostly look like ordinary ASCII text files; |
9 | you can edit them with any text editor you like. |
10 | |
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11 | Writing \i{paragraphs of ordinary text} is very simple: you just |
12 | write ordinary text in the ordinary way. You can wrap a paragraph |
13 | across more than one line using \i{line breaks} in the text file, |
14 | and Halibut will ignore this when it \I{wrapping paragraphs}rewraps |
15 | the paragraph for each output format. To separate paragraphs, use a |
16 | \i{blank line} (i.e. two consecutive line breaks). For example, a |
17 | fragment of Halibut input looking like this: |
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18 | |
19 | \c This is a line of text. |
20 | \c This is another line of text. |
21 | \c |
22 | \c This line is separated from the previous one by a blank line. |
23 | |
24 | will produce two paragraphs looking like this: |
25 | |
26 | \quote{ |
27 | This is a line of text. |
28 | This is another line of text. |
29 | |
30 | This line is separated from the previous one by a blank line. |
31 | } |
32 | |
33 | The first two lines of the input have been merged together into a |
34 | single paragraph, and the line break in the input file was treated |
35 | identically to the spaces between the individual words. |
36 | |
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37 | Halibut is designed to have very few \I{escaping, special |
38 | characters}\i{special characters}. The only printable characters in |
39 | Halibut input which will not be treated exactly literally in the |
40 | output are the \i{backslash} (\c{\\}) and the \i{braces} (\c{\{} and |
41 | \c{\}}). If you do not use these characters, \e{everything} else you |
42 | might type in normal ASCII text is perfectly safe. If you do need to |
43 | use any of those three characters in your document, you will have to |
44 | precede each one with a backslash. Hence, for example, you could |
45 | write |
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46 | |
47 | \c This \\ is a backslash, and these are \{braces\}. |
48 | |
49 | and Halibut would generate the text |
50 | |
51 | \quote{ |
52 | This \\ is a backslash, and these are \{braces\}. |
53 | } |
54 | |
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55 | If you want to write your input file in a character set other than |
56 | ASCII, you can do so by using the \c{\\cfg\{input-charset\}} |
57 | command. See \k{input-config} for details of this. |
58 | |
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59 | \H{input-inline} Simple \i{inline formatting commands} |
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60 | |
61 | Halibut formatting commands all begin with a backslash, followed by |
62 | a word or character identifying the command. Some of them then use |
63 | braces to surround one or more pieces of text acted on by the |
64 | command. (In fact, the \c{\\\\}, \c{\\\{} and \c{\\\}} sequences you |
65 | met in \k{input-basics} are themselves formatting commands.) |
66 | |
67 | This section describes some simple formatting commands you can use |
68 | in Halibut documents. The commands in this section are \e{inline} |
69 | commands, which means you can use them in the middle of a paragraph. |
70 | \K{input-para} describes some \e{paragraph} commands, which affect a |
71 | whole paragraph at a time. |
72 | |
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73 | Many of these commands are followed by a pair of braces surrounding |
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74 | some text. In all cases, it is perfectly safe to have a \i{line break} |
c63ce2c7 |
75 | (in the input file) within those braces; Halibut will treat that |
76 | exactly the same as a space. For example, these two paragraphs will |
77 | be treated identically: |
78 | |
79 | \c Here is some \e{emphasised |
80 | \c text}. |
81 | \c |
82 | \c Here is some \e{emphasised text}. |
83 | |
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84 | \S{input-emph} \c{\\e}: Emphasising text |
85 | |
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86 | Possibly the most obvious piece of formatting you might want |
87 | to use in a document is \i\e{emphasis}. |
88 | To emphasise text, you use the \i\c{\\e} command, and follow it up |
89 | with the text to be emphasised in braces. For example, the first |
90 | sentence in this paragraph was generated using the Halibut input |
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91 | |
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92 | \c Possibly the most obvious piece of formatting you might want |
93 | \c to use in a document is \e{emphasis}. |
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94 | |
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95 | \S{input-code} \c{\\c} and \c{\\cw}: Displaying \i{computer code} inline |
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96 | |
97 | Halibut was primarily designed to produce software manuals. It can |
98 | be used for other types of document as well, but software manuals |
99 | are its speciality. |
100 | |
101 | In software manuals, you often want to format text in a way that |
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102 | indicates that it is something you might see displayed \i{verbatim} |
103 | on a computer screen. In printed manuals, this is typically done by |
104 | setting that text in a font which is obviously \I{fixed-width |
105 | font}fixed-width. This provides a visual cue that the text being |
106 | displayed is code, and it also ensures that punctuation marks are |
107 | clearly separated and shown individually (so that a user can copy |
108 | the text accurately and conveniently). |
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109 | |
110 | Halibut provides \e{two} commands for this, which are subtly |
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111 | different. The names of those commands are \i\c{\\c} (\q{code}) and |
112 | \i\c{\\cw} (\q{\i{weak code}}). You use them just like \c{\\e}, by |
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113 | following them with some text in braces. For example, this... |
114 | |
115 | \c This sentence contains some \c{code} and some \cw{weak code}. |
116 | |
117 | ... produces this: |
118 | |
119 | \quote{ |
120 | This sentence contains some \c{code} and some \cw{weak code}. |
121 | } |
122 | |
123 | The distinction between code and weak code is mainly important when |
124 | producing plain text output. Plain text output is typically viewed |
125 | in a fixed-width font, so there is no need (and no way) to change |
126 | font in order to make the order of punctuation marks clear. However, |
127 | marking text as code is also \e{sometimes} done to provide a visual |
128 | distinction between it and the text around it, so that the reader |
129 | knows where the literal computer text starts and stops; and in plain |
130 | text, this cannot be done by changing font, so there needs to be an |
131 | alternative way. |
132 | |
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133 | So in the plain text output format, things marked as code (\c{\\c}) |
134 | will be surrounded by quote marks, so that it's obvious where they |
135 | start and finish. Things marked as weak code (\c{\\cw}) will not |
136 | look any different from normal text. |
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137 | |
138 | I recommend using weak code for any application where it is |
139 | \e{obvious} that the text is literal computer input or output. For |
140 | example, if the text is capitalised, that's usually good enough. If |
141 | I talk about the Pentium's \cw{EAX} and \cw{EDX} registers, for |
142 | example, you don't need quotes to notice that those are special; so |
143 | I would write that in Halibut as \q{\c{the Pentium's \\cw\{EAX\} and |
144 | \\cw\{EDX\} registers}}. But if I'm talking about the Unix command |
145 | \c{man}, which is an ordinary English word in its own right, a reader |
146 | might be slightly confused if it appeared in the middle of a |
147 | sentence undecorated; so I would write that as \q{\c{the Unix command |
148 | \\c\{man\}}}. |
149 | |
150 | In summary: |
151 | |
152 | \b \c{\\c} means \q{this text \e{must} be visually distinct from the |
153 | text around it}. Halibut's various output formats will do this by |
154 | changing the font if possible, or by using quotes if not. |
155 | |
156 | \b \c{\\cw} means \q{it would be nice to display this text in a |
157 | fixed-width font if possible, but it's not essential}. |
158 | |
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159 | In really extreme cases, you might want Halibut to use \i{quotation |
160 | marks} even in output formats which can change font. In |
161 | \k{input-date}, for example, I mention the special formatting |
162 | command \q{\cw{\\.}}. If that appeared at the end of a sentence |
163 | \e{without} the quotes, then the two adjacent full stops would look |
164 | pretty strange even if they were obviously in different fonts. So I |
165 | used the \c{\\q} command to provide my own set of quotes, and then |
166 | used \c{\\cw} rather than \c{\\c} to ensure that none of Halibut's |
167 | output formats would add another set of quotes: |
168 | |
169 | \c the special formatting command \q{\cw{\\.}}. |
170 | |
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171 | There is a separate mechanism for displaying computer code in an |
172 | entire paragraph; see \k{input-codepara} for that one. |
173 | |
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174 | \S{input-quotes} \c{\\q}: \ii{Quotation marks} |
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175 | |
176 | Halibut's various output formats don't all use the same conventions |
177 | for displaying text in ordinary quotation marks (\q{like these}). |
178 | Some output formats have access to proper matched quote characters, |
179 | whereas others are restricted to using plain ASCII. Therefore, it is |
180 | not ideal to use the ordinary ASCII double quote character in your |
181 | document (although you can if you like). |
182 | |
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183 | Halibut provides the formatting command \i\c{\\q} to indicate quoted |
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184 | text. If you write |
185 | |
186 | \c Here is some \q{text in quotes}. |
187 | |
188 | then Halibut will print |
189 | |
190 | \quote{ |
191 | Here is some \q{text in quotes}. |
192 | } |
193 | |
194 | and in every output format Halibut generates, it will choose the |
195 | best quote characters available to it in that format. |
196 | |
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197 | You can still use the ordinary quote characters of your choice if |
198 | you prefer; or you could even use the \c{\\u} command (see |
199 | \k{input-unicode}) to generate \i{Unicode matched quotes} (single or |
200 | double) in a way which will automatically fall back to the normal |
201 | ASCII one if they aren't available. But I recommend using the |
202 | built-in \c{\\q} command in most cases, because it's simple and does |
203 | the best it can everywhere. |
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204 | |
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205 | If you're using the \c{\\c} or \c{\\cw} commands to display literal |
206 | computer code, you will probably want to use literal \i{ASCII quote |
207 | characters}, because it is likely to matter precisely which quote |
208 | character you use. In fact, Halibut actually \e{disallows} the use |
209 | of \c{\\q} within either of \c{\\c} and \c{\\cw}, since this |
210 | simplifies some of the output formats. |
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211 | |
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212 | \S{input-nonbreaking} \c{\\-} and \c{\\_}: \ii{Non-breaking hyphens} |
213 | and \I{non-breaking spaces}spaces |
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214 | |
215 | If you use an ordinary hyphen in the middle of a word (such as |
216 | \q{built-in}), Halibut's output formats will feel free to break a |
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217 | line after that hyphen when \i{wrapping paragraphs}. This is fine |
218 | for a word like \q{built-in}, but if you were displaying some |
219 | literal computer code such as the Emacs command |
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220 | \c{M\-x\_psychoanalyze\-pinhead}, you might prefer to see the whole |
221 | hyphenated word treated as an unbreakable block. In some cases, you |
222 | might even want to prevent the \e{space} in that command from |
223 | becoming a line break. |
224 | |
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225 | For these purposes, Halibut provides the commands \i\c{\\-} and |
226 | \i\c{\\_}, which generate a non-breaking hyphen and a non-breaking |
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227 | space respectively. So the above Emacs command might be written as |
228 | |
229 | \c the Emacs command \c{M\-x\_psychoanalyze\-pinhead} |
230 | |
231 | Unfortunately, some of Halibut's output formats do not support |
232 | non-breaking hyphens, and others don't support \e{breaking} hyphens! |
233 | So Halibut cannot promise to honour these commands in all situations. |
234 | All it can do is make a best effort. |
235 | |
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236 | \S{input-date} \c{\\date}: Automatic \i{date} generation |
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237 | |
238 | Sometimes you might want your document to give an up-to-date |
239 | indication of the date on which it was run through Halibut. |
240 | |
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241 | Halibut supplies the \i\c{\\date} command to do this. In its |
242 | simplest form, you simply say |
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243 | |
244 | \c This document was generated on \date. |
245 | |
246 | and Halibut generates something like |
247 | |
248 | \quote{ |
249 | This document was generated on \date. |
250 | } |
251 | |
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252 | You can follow the \c{\\date} command directly with punctuation (as |
253 | in this example, where it is immediately followed by a full stop), |
254 | but if you try to follow it with an alphabetic or numeric character |
255 | (such as writing \c{\\dateZ}) then Halibut will assume you are |
256 | trying to invoke the name of a macro command you have defined |
257 | yourself, and will complain if no such command exists. To get round |
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258 | this you can use the special \q{\cw{\\.}} do-nothing command. See |
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259 | \k{input-macro} for more about general Halibut command syntax and |
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260 | \q{\cw{\\.}}. |
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261 | |
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262 | If you would prefer the date to be generated in a specific format, |
263 | you can follow the \c{\\date} command with a format specification in |
264 | braces. The format specification will be run through the standard C |
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265 | function \i\c{strftime}, so any format acceptable to that function |
266 | is acceptable here as well. I won't document the format here, |
267 | because the details vary from computer to computer (although there |
268 | is a standard core which should be supported everywhere). You should |
269 | look at your local system's manual for \c{strftime} for details. |
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270 | |
271 | Here's an example which generates the date in the international |
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272 | standard \i{ISO 8601} format: |
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273 | |
274 | \c This document was generated on \date{%Y-%m-%d %H:%M:%S}. |
275 | |
276 | And here's some sample output from that command: |
277 | |
278 | \quote{ |
279 | This document was generated on \date{%Y-%m-%d %H:%M:%S}. |
280 | } |
281 | |
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282 | \S{input-weblink} \c{\\W}: \i{WWW hyperlinks} |
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283 | |
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284 | Since one of Halibut's output formats is \i{HTML}, it's obviously |
285 | useful to be able to provide \I{linking to web sites}links to |
286 | arbitrary \i{web sites} in a Halibut document. |
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287 | |
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288 | This is done using the \i\c{\\W} command. \c{\\W} expects to be |
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289 | followed by \e{two} sets of braces. In the first set of braces you |
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290 | put a \i{URL}; in the second set you put the text which should be a |
291 | \i{hyperlink}. For example, you might write |
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292 | |
293 | \c Try searching on \W{http://www.google.com/}{Google}. |
294 | |
295 | and Halibut would generate |
296 | |
297 | \quote{ |
298 | Try searching on \W{http://www.google.com/}{Google}. |
299 | } |
300 | |
301 | Note that hyperlinks, like the non-breaking commands discussed in |
302 | \k{input-nonbreaking}, are \e{discretionary}: if an output format |
303 | does not support them then they will just be left out completely. So |
304 | unless you're \e{only} intending to use the HTML output format, you |
305 | should avoid storing vital content in the URL part of a \c{\\W} |
306 | command. The Google example above is reasonable (because most users |
307 | are likely to be able to find Google for themselves even without a |
308 | convenient hyperlink leading straight there), but if you really need |
309 | to direct users to a specific web site, you will need to give the |
310 | URL in actual displayed text (probably displayed as code as well). |
311 | However, there's nothing to stop you making it a hyperlink \e{as |
312 | well} for the convenience of HTML readers. |
313 | |
314 | The \c{\\W} command supports a piece of extra syntax to make this |
315 | convenient for you. You can specify \c{\\c} or \c{\\cw} \e{between} |
316 | the first and second pairs of braces. For example, you might write |
317 | |
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318 | \c Google is at \W{http://www.google.com/}\cw{www.google.com}. |
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319 | |
320 | and Halibut would produce |
321 | |
322 | \quote{ |
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323 | Google is at \W{http://www.google.com/}\cw{www.google.com}. |
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324 | } |
325 | |
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326 | If you want the link text to be an index term as well, you can also |
327 | specify \c{\\i} or \c{\\ii}; this has to come before \c{\\c} or |
328 | \c{\\cw} if both are present. (See \k{input-index} for more about |
329 | indexing.) |
330 | |
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331 | \S{input-unicode} \c{\\u}: Specifying arbitrary \i{Unicode} |
332 | characters |
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333 | |
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334 | Halibut has extensive support for Unicode and character set |
335 | conversion. You can specify any (reasonably well known) \i{character |
336 | set} for your input document, and Halibut will convert it all to |
337 | Unicode as it reads it in. See \k{input-config} for more details of |
338 | this. |
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339 | |
340 | If you need to specify a Unicode character in your input document |
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341 | which is not supported by the input character set you have chosen, |
342 | you can use the \i\c{\\u} command to do this. \c{\\u} expects to be |
343 | followed by a sequence of hex digits; so that \c{\\u0041}, for |
344 | example, denotes the Unicode character \cw{0x0041}, which is the |
345 | capital letter A. |
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346 | |
347 | If a Unicode character specified in this way is not supported in a |
348 | particular \e{output} format, you probably don't just want it to be |
349 | omitted. So you can put a pair of braces after the \c{\\u} command |
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350 | containing \i{fallback text}. For example, to specify an amount of |
351 | money in euros, you might write this: |
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352 | |
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353 | \c This is likely to cost \u20AC{EUR\_}2500 at least. |
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354 | |
355 | Halibut will render that as a Euro sign \e{if available}, and |
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356 | the text \q{EUR\_} if not. In the output format you're currently |
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357 | reading in, the above input generates this: |
358 | |
359 | \quote{ |
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360 | This is likely to cost \u20AC{EUR\_}2500 at least. |
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361 | } |
362 | |
363 | If you read it in other formats, you may see different results. |
364 | |
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365 | \S{input-xref} \i\c{\\k} and \I{\\K-upper}\c{\\K}: |
366 | \ii{Cross-references} to other sections |
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367 | |
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368 | \K{intro-features} mentions that Halibut \I{section numbers}numbers |
369 | the sections of your document automatically, and can generate |
370 | cross-references to them on request. \c{\\k} and \c{\\K} are the |
371 | commands used to generate those cross-references. |
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372 | |
373 | To use one of these commands, you simply follow it with a pair of |
374 | braces containing the keyword for the section in question. For |
375 | example, you might write something like |
376 | |
377 | \c \K{input-xref} expands on \k{intro-features}. |
378 | |
379 | and Halibut would generate something like |
380 | |
381 | \quote{ |
382 | \K{input-xref} expands on \k{intro-features}. |
383 | } |
384 | |
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385 | The \i{keywords} \c{input-xref} and \c{intro-features} are |
386 | \i{section keywords} used in this manual itself. In your own |
387 | document, you would have supplied a keyword for each one of your own |
388 | sections, and you would provide your own keywords for the \c{\\k} |
389 | command to work on. |
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390 | |
391 | The difference between \c{\\k} and \c{\\K} is simply that \c{\\K} |
392 | starts the cross-reference text with a capital letter; so you would |
393 | use \c{\\K} at the beginning of a sentence, and \c{\\k} everywhere |
394 | else. |
395 | |
396 | In output formats which permit it, cross-references act as |
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397 | \i{hyperlinks}, so that clicking the mouse on a cross-reference |
398 | takes you straight to the referenced section. |
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399 | |
400 | The \c{\\k} commands are also used for referring to entries in a |
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401 | \i{bibliography} (see \k{input-biblio} for more about |
402 | bibliographies), and can also be used for referring to an element of |
403 | a \i{numbered list} by its number (see \k{input-list-number} for |
404 | more about numbered lists). |
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405 | |
406 | See \k{input-sections} for more about chapters and sections. |
407 | |
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408 | \S{input-inline-comment} \i\c{\\#}: Inline comments |
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409 | |
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410 | If you want to include \i{comments} in your Halibut input, to be seen |
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411 | when reading it directly but not copied into the output text, then |
412 | you can use \c{\\#} to do this. If you follow \c{\\#} with text in |
413 | braces, that text will be ignored by Halibut. |
414 | |
415 | For example, you might write |
416 | |
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417 | \c The typical behaviour of an antelope \#{do I mean |
418 | \c gazelle?} is... |
11f2edfa |
419 | |
420 | and Halibut will simply leave out the aside about gazelles, and will |
421 | generate nothing but |
422 | |
423 | \quote{ |
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424 | The typical behaviour of an antelope \#{do I mean |
425 | gazelle?} is... |
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426 | } |
427 | |
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428 | This command will respect nested braces, so you can use it to |
429 | comment out sections of Halibut markup: |
430 | |
431 | \c This function is \#{very, \e{very}} important. |
432 | |
433 | In this example, the comment lasts until the final closing brace (so |
434 | that the whole \q{very, \e{very}} section is commented out). |
435 | |
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436 | The \c{\\#} command can also be used to produce a whole-paragraph |
437 | comment; see \k{input-commentpara} for details of that. |
438 | |
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439 | \H{input-para} \ii{Paragraph-level commands} |
11f2edfa |
440 | |
441 | This section describes Halibut commands which affect an entire |
442 | paragraph, or sometimes even \e{more} than one paragraph, at a time. |
443 | |
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444 | \S{input-codepara} \i\c{\\c}: Displaying whole \I{code |
445 | paragraphs}paragraphs of \i{computer code} |
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446 | |
447 | \K{input-code} describes a mechanism for displaying computer code in |
448 | the middle of a paragraph, a few words at a time. |
449 | |
450 | However, this is often not enough. Often, in a computer manual, you |
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451 | really want to show several lines of code in a \i{display |
452 | paragraph}. |
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453 | |
454 | This is also done using the \c{\\c} command, in a slightly different |
455 | way. Instead of using it in the middle of a paragraph followed by |
456 | braces, you can use it at the start of each line of a paragraph. For |
457 | example, you could write |
458 | |
459 | \c \c #include <stdio.h> |
460 | \c \c |
461 | \c \c int main(int argc, char **argv) { |
462 | \c \c printf("hello, world\n"); |
463 | \c \c return 0; |
464 | \c \c } |
465 | |
466 | and Halibut would generate |
467 | |
468 | \quote{ |
469 | |
470 | \c #include <stdio.h> |
471 | \c |
472 | \c int main(int argc, char **argv) { |
473 | \c printf("hello, world\n"); |
474 | \c return 0; |
475 | \c } |
476 | |
477 | } |
478 | |
479 | Note that the above paragraph makes use of a backslash and a pair of |
480 | braces, and does \e{not} need to escape them in the way described in |
481 | \k{input-basics}. This is because code paragraphs formatted in this |
482 | way are a special case; the intention is that you can just copy and |
fc8e7adb |
483 | paste a lump of code out of your program, put \q{\cw{\\c }} at the |
11f2edfa |
484 | start of every line, and simply \e{not have to worry} about the |
485 | details - you don't have to go through the whole block looking for |
486 | characters to escape. |
487 | |
488 | Since a backslash inside a code paragraph generates a literal |
489 | backslash, this means you cannot use any other Halibut formatting |
490 | commands inside a code paragraph. In particular, if you want to |
491 | emphasise a particular word in the paragraph, you can't do that |
492 | using \c{\\e} (\k{input-emph}) in the normal way. |
493 | |
339cbe09 |
494 | Therefore, Halibut provides an alternative means of \i{emphasis in |
495 | code paragraphs}. Each line beginning with \c{\\c} can optionally be |
11f2edfa |
496 | followed by a single line beginning with \c{\\e}, indicating the |
497 | emphasis in that line. The emphasis line contains the letters \c{b} |
498 | and \c{i} (for \q{bold} and \q{italic}, although some output formats |
339cbe09 |
499 | might render \c{i} as underlining instead of italics), positioned to |
500 | line up under the parts of the text that you want emphasised. |
11f2edfa |
501 | |
339cbe09 |
502 | For example, if you wanted to do \i{syntax highlighting} on the |
503 | above C code by highlighting the preprocessor command in italic and |
504 | the keywords in bold, you might do it like this: |
11f2edfa |
505 | |
506 | \c \c #include <stdio.h> |
507 | \c \e iiiiiiiiiiiiiiiiii |
508 | \c \c |
509 | \c \c int main(int argc, char **argv) { |
510 | \c \e bbb bbb bbbb |
511 | \c \c printf("hello, world\n"); |
512 | \c \c return 0; |
513 | \c \e bbbbbb |
514 | \c \c } |
515 | |
516 | and Halibut would generate: |
517 | |
518 | \quote{ |
519 | |
520 | \c #include <stdio.h> |
521 | \e iiiiiiiiiiiiiiiiii |
522 | \c |
523 | \c int main(int argc, char **argv) { |
524 | \e bbb bbb bbbb |
525 | \c printf("hello, world\n"); |
526 | \c return 0; |
527 | \e bbbbbb |
528 | \c } |
529 | |
530 | } |
531 | |
532 | Note that not every \c{\\c} line has to be followed by a \c{\\e} |
533 | line; they're optional. |
534 | |
535 | Also, note that highlighting within a code paragraph is |
536 | \e{discretionary}. Not all of Halibut's output formats can support |
537 | it (plain text, in particular, has no sensible way to do it). Unless |
538 | you know you are using a restricted range of output formats, you |
539 | should use highlighting in code paragraphs \e{only} as a visual aid, |
540 | and not rely on it to convey any vital semantic content. |
541 | |
339cbe09 |
542 | \S{input-lists} \c{\\b}, \c{\\n}, \c{\\dt}, \c{\\dd}, \c{\\lcont}: |
543 | \ii{Lists} |
11f2edfa |
544 | |
545 | Halibut supports bulletted lists, numbered lists and description |
546 | lists. |
547 | |
339cbe09 |
548 | \S2{input-list-bullet} \i\c{\\b}: \ii{Bulletted lists} |
11f2edfa |
549 | |
550 | To create a bulletted list, you simply prefix each paragraph |
551 | describing a bullet point with the command \c{\\b}. For example, this |
552 | Halibut input: |
553 | |
554 | \c Here's a list: |
555 | \c |
556 | \c \b One. |
557 | \c |
558 | \c \b Two. |
559 | \c |
560 | \c \b Three. |
561 | |
562 | would produce this Halibut output: |
563 | |
564 | \quote{ |
565 | Here's a list: |
566 | |
567 | \b One. |
568 | |
569 | \b Two. |
570 | |
571 | \b Three. |
572 | } |
573 | |
339cbe09 |
574 | \S2{input-list-number} \i\c{\\n}: \ii{Numbered lists} |
11f2edfa |
575 | |
576 | Numbered lists are just as simple: instead of \c{\\b}, you use |
577 | \c{\\n}, and Halibut takes care of getting the numbering right for |
578 | you. For example: |
579 | |
580 | \c Here's a list: |
581 | \c |
582 | \c \n One. |
583 | \c |
584 | \c \n Two. |
585 | \c |
586 | \c \n Three. |
587 | |
588 | This produces the Halibut output: |
589 | |
590 | \quote{ |
591 | Here's a list: |
592 | |
593 | \n One. |
594 | |
595 | \n Two. |
596 | |
597 | \n Three. |
598 | } |
599 | |
600 | The disadvantage of having Halibut sort out the list numbering for |
601 | you is that if you need to refer to a list item by its number, you |
fc8e7adb |
602 | can't reliably know the number in advance (because if you later add |
603 | another item at the start of the list, the numbers will all change). |
604 | To get round this, Halibut allows an optional keyword in braces |
605 | after the \c{\\n} command. This keyword can then be referenced using |
606 | the \c{\\k} or \c{\\K} command (see \k{input-xref}) to provide the |
607 | number of the list item. For example: |
11f2edfa |
608 | |
609 | \c Here's a list: |
610 | \c |
611 | \c \n One. |
612 | \c |
613 | \c \n{this-one} Two. |
614 | \c |
615 | \c \n Three. |
616 | \c |
617 | \c \n Now go back to step \k{this-one}. |
618 | |
619 | This produces the following output: |
620 | |
621 | \quote{ |
622 | Here's a list: |
623 | |
624 | \n One. |
625 | |
626 | \n{this-one} Two. |
627 | |
628 | \n Three. |
629 | |
630 | \n Now go back to step \k{this-one}. |
631 | } |
632 | |
acbb8b72 |
633 | The keyword you supply after \c{\\n} is allowed to contain escaped |
634 | special characters (\c{\\\\}, \c{\\\{} and \c{\\\}}), but should not |
635 | contain any other Halibut markup. It is intended to be a word or two |
636 | of ordinary text. (This also applies to keywords used in other |
637 | commands, such as \c{\\B} and \c{\\C}). |
638 | |
339cbe09 |
639 | \S2{input-list-description} \i\c{\\dt} and \i\c{\\dd}: |
640 | \ii{Description lists} |
11f2edfa |
641 | |
339cbe09 |
642 | To write a description list, you prefix alternate paragraphs with |
643 | the \c{\\dt} (\q{described thing}) and \c{\\dd} (description) |
644 | commands. For example: |
11f2edfa |
645 | |
646 | \c \dt Pelican |
647 | \c |
648 | \c \dd This is a large bird with a big beak. |
649 | \c |
650 | \c \dt Panda |
651 | \c |
652 | \c \dd This isn't. |
653 | |
654 | This produces the following output: |
655 | |
656 | \quote{ |
657 | |
658 | \dt Pelican |
659 | |
660 | \dd This is a large bird with a big beak. |
661 | |
662 | \dt Panda |
663 | |
664 | \dd This isn't. |
665 | |
666 | } |
667 | |
339cbe09 |
668 | \S2{input-list-continuation} \ii{Continuing list items} into further |
11f2edfa |
669 | paragraphs |
670 | |
671 | All three of the above list types assume that each list item is a |
672 | single paragraph. For a short, snappy list in which each item is |
673 | likely to be only one or two words, this is perfectly sufficient; |
674 | but occasionally you will find you want to include several |
339cbe09 |
675 | paragraphs in a single list item, or even to \I{nested lists}nest |
676 | other types of paragraph (such as code paragraphs, or other lists) |
677 | inside a list item. |
11f2edfa |
678 | |
339cbe09 |
679 | To do this, you use the \i\c{\\lcont} command. This is a command |
680 | which can span \e{multiple} paragraphs. |
11f2edfa |
681 | |
682 | After the first paragraph of a list item, include the text |
683 | \c{\\lcont\{}. This indicates that the subsequent paragraph(s) are a |
684 | \e{continuation} of the list item that has just been seen. So you |
685 | can include further paragraphs, and eventually include a closing |
686 | brace \c{\}} to finish the list continuation. After that, you can |
687 | either continue adding other items to the original list, or stop |
688 | immediately and return to writing normal paragraphs of text. |
689 | |
690 | Here's a (long) example. |
691 | |
692 | \c Here's a list: |
693 | \c |
694 | \c \n One. This item is followed by a code paragraph: |
695 | \c |
696 | \c \lcont{ |
697 | \c |
698 | \c \c code |
699 | \c \c paragraph |
700 | \c |
701 | \c } |
702 | \c |
703 | \c \n Two. Now when I say \q{two}, I mean: |
704 | \c |
705 | \c \lcont{ |
706 | \c |
707 | \c \n Two, part one. |
708 | \c |
709 | \c \n Two, part two. |
710 | \c |
711 | \c \n Two, part three. |
712 | \c |
713 | \c } |
714 | \c |
715 | \c \n Three. |
716 | |
717 | The output produced by this fragment is: |
718 | |
719 | \quote{ |
720 | |
721 | Here's a list: |
722 | |
723 | \n One. This item is followed by a code paragraph: |
724 | |
725 | \lcont{ |
726 | |
727 | \c code |
728 | \c paragraph |
729 | |
730 | } |
731 | |
732 | \n Two. Now when I say \q{two}, I mean: |
733 | |
734 | \lcont{ |
735 | |
736 | \n Two, part one. |
737 | |
738 | \n Two, part two. |
739 | |
740 | \n Two, part three. |
741 | |
742 | } |
743 | |
744 | \n Three. |
745 | |
746 | } |
747 | |
fc8e7adb |
748 | This syntax might seem a little bit inconvenient, and perhaps |
11f2edfa |
749 | counter-intuitive: you might expect the enclosing braces to have to |
750 | go around the \e{whole} list item, rather than everything except the |
751 | first paragraph. |
752 | |
753 | \c{\\lcont} is a recent addition to the Halibut input language; |
754 | previously, \e{all} lists were required to use no more than one |
755 | paragraph per list item. So it's certainly true that this feature |
756 | looks like an afterthought because it \e{is} an afterthought, and |
757 | it's possible that if I'd been designing the language from scratch |
758 | with multiple-paragraph list items in mind, I would have made it |
759 | look different. |
760 | |
761 | However, the advantage of doing it this way is that no enclosing |
762 | braces are required in the \e{common} case: simple lists with only |
763 | one paragraph per item are really, really easy to write. So I'm not |
764 | too unhappy with the way it turned out; it obeys the doctrine of |
765 | making simple things simple, and difficult things possible. |
766 | |
767 | Note that \c{\\lcont} can only be used on \c{\\b}, \c{\\n} and |
768 | \c{\\dd} paragraphs; it cannot be used on \c{\\dt}. |
769 | |
339cbe09 |
770 | \S{input-rule} \i\c{\\rule}: \ii{Horizontal rules} |
11f2edfa |
771 | |
772 | The command \c{\\rule}, appearing on its own as a paragraph, will |
773 | cause a horizontal rule to be drawn, like this: |
774 | |
775 | \c Some text. |
776 | \c |
777 | \c \rule |
778 | \c |
779 | \c Some more text. |
780 | |
781 | This produces the following output: |
782 | |
783 | \quote{ |
784 | |
785 | Some text. |
786 | |
787 | \rule |
788 | |
789 | Some more text. |
790 | |
791 | } |
792 | |
339cbe09 |
793 | \S{input-quote} \i\c{\\quote}: \ii{Indenting multiple paragraphs} as a |
794 | long \i{quotation} |
11f2edfa |
795 | |
796 | Quoting verbatim text using a code paragraph (\k{input-codepara}) is |
797 | not always sufficient for your quoting needs. Sometimes you need to |
798 | quote some normally formatted text, possibly in multiple paragraphs. |
339cbe09 |
799 | This is similar to HTML's \i\cw{<BLOCKQUOTE>} command. |
11f2edfa |
800 | |
801 | To do this, you can use the \c{\\quote} command. Like \c{\\lcont}, |
802 | this is a command which expects to enclose at least one paragraph |
803 | and possibly more. Simply write \c{\\quote\{} at the beginning of |
804 | your quoted section, and \c{\}} at the end, and the paragraphs in |
805 | between will be formatted to indicate that they are a quotation. |
806 | |
807 | (This very manual, in fact, uses this feature a lot: all of the |
fc8e7adb |
808 | examples of Halibut input followed by Halibut output have the output |
809 | quoted using \c{\\quote}.) |
11f2edfa |
810 | |
811 | Here's some example Halibut input: |
812 | |
813 | \c In \q{Through the Looking Glass}, Lewis Carroll wrote: |
814 | \c |
815 | \c \quote{ |
816 | \c |
817 | \c \q{The question is,} said Alice, \q{whether you \e{can} make |
818 | \c words mean so many different things.} |
819 | \c |
fc8e7adb |
820 | \c \q{The question is,} said Humpty Dumpty, \q{who is to be |
821 | \c master - that's all.} |
11f2edfa |
822 | \c |
823 | \c } |
824 | \c |
825 | \c So now you know. |
826 | |
827 | The output generated by this is: |
828 | |
829 | \quote{ |
830 | |
831 | In \q{Through the Looking Glass}, Lewis Carroll wrote: |
832 | |
833 | \quote{ |
834 | |
835 | \q{The question is,} said Alice, \q{whether you \e{can} make |
836 | words mean so many different things.} |
837 | |
fc8e7adb |
838 | \q{The question is,} said Humpty Dumpty, \q{who is to be |
839 | master - that's all.} |
11f2edfa |
840 | |
841 | } |
842 | |
843 | So now you know. |
844 | |
845 | } |
846 | |
da090173 |
847 | \S{input-sections} \I{\\C-upper}\c{\\C}, \i\c{\\H}, \i\c{\\S}, |
848 | \i\c{\\A}, \I{\\U-upper}\c{\\U}: Chapter and \i{section headings} |
11f2edfa |
849 | |
339cbe09 |
850 | \K{intro-features} mentions that Halibut \I{section |
851 | numbering}numbers the sections of your document automatically, and |
852 | can generate cross-references to them on request; \k{input-xref} |
853 | describes the \c{\\k} and \c{\\K} commands used to generate the |
854 | cross-references. This section describes the commands used to set up |
855 | the sections in the first place. |
11f2edfa |
856 | |
857 | A paragraph beginning with the \c{\\C} command defines a chapter |
858 | heading. The \c{\\C} command expects to be followed by a pair of |
859 | braces containing a keyword for the chapter; this keyword can then |
860 | be used with the \c{\\k} and \c{\\K} commands to generate |
861 | cross-references to the chapter. After the closing brace, the rest |
862 | of the paragraph is used as the displayed chapter title. So the |
863 | heading for the current chapter of this manual, for example, is |
864 | written as |
865 | |
866 | \c \C{input} Halibut input format |
867 | |
868 | and this allows me to use the command \c{\\k\{input\}} to generate a |
869 | cross-reference to that chapter somewhere else. |
870 | |
acbb8b72 |
871 | The \I{keyword syntax}keyword you supply after one of these commands |
872 | is allowed to contain escaped special characters (\c{\\\\}, \c{\\\{} |
873 | and \c{\\\}}), but should not contain any other Halibut markup. It |
874 | is intended to be a word or two of ordinary text. (This also applies |
875 | to keywords used in other commands, such as \c{\\B} and \c{\\n}). |
876 | |
11f2edfa |
877 | The next level down from \c{\\C} is \c{\\H}, for \q{heading}. This |
878 | is used in exactly the same way as \c{\\C}, but section headings |
879 | defined with \c{\\H} are considered to be part of a containing |
880 | chapter, and will be numbered with a pair of numbers. After \c{\\H} |
881 | comes \c{\\S}, and if necessary you can then move on to \c{\\S2}, |
882 | \c{\\S3} and so on. |
883 | |
884 | For example, here's a sequence of heading commands. Normally these |
885 | commands would be separated at least by blank lines (because each is |
886 | a separate paragraph), and probably also by body text; but for the |
887 | sake of brevity, both of those have been left out in this example. |
888 | |
889 | \c \C{foo} Using Foo |
890 | \c \H{foo-intro} Introduction to Foo |
891 | \c \H{foo-running} Running the Foo program |
892 | \c \S{foo-inter} Running Foo interactively |
893 | \c \S{foo-batch} Running Foo in batch mode |
894 | \c \H{foo-trouble} Troubleshooting Foo |
895 | \c \C{bar} Using Bar instead of Foo |
896 | |
897 | This would define two chapters with keywords \c{foo} and \c{bar}, |
898 | which would end up being called Chapter 1 and Chapter 2 (unless |
899 | there were other chapters before them). The sections \c{foo-intro}, |
900 | \c{foo-running} and \c{foo-trouble} would be referred to as Section |
901 | 1.1, Section 1.2 and Section 1.3 respectively; the subsections |
902 | \c{foo-inter} and \c{foo-batch} would be Section 1.2.1 and Section |
339cbe09 |
903 | 1.2.2. If there had been a \i\c{\\S2} command within one of those, |
904 | it would have been something like Section 1.2.1.1. |
11f2edfa |
905 | |
906 | If you don't like the switch from \c{\\H} to \c{\\S}, you can use |
907 | \c{\\S1} as a synonym for \c{\\S} and \c{\\S0} as a synonym for |
908 | \c{\\H}. Chapters are still designated with \c{\\C}, because they |
909 | need to be distinguished from other types of chapter such as |
910 | appendices. (Personally, I like the \c{\\C},\c{\\H},\c{\\S} notation |
911 | because it encourages me to think of my document as a hard disk :-) |
912 | |
339cbe09 |
913 | You can define an \i{appendix} by using \c{\\A} in place of \c{\\C}. |
11f2edfa |
914 | This is no different from a chapter except that it's given a letter |
915 | instead of a number, and cross-references to it will say \q{Appendix |
916 | A} instead of \q{Chapter 9}. Subsections of an appendix will be |
917 | numbered \q{A.1}, \q{A.2}, \q{A.2.1} and so on. |
918 | |
339cbe09 |
919 | \I{renaming sections}If you want a particular section to be referred |
920 | to as something other than a \q{chapter}, \q{section} or |
921 | \q{appendix}, you can include a second pair of braces after the |
922 | keyword. For example, if you're \i{writing a FAQ} chapter and you |
923 | want cross-references between questions to refer to \q{question |
924 | 1.2.3} instead of \q{section 1.2.3}, you can write each section |
925 | heading as |
11f2edfa |
926 | |
927 | \c \S{question-about-fish}{Question} What about fish? |
928 | |
929 | (The word \q{Question} should be given with an initial capital |
930 | letter. Halibut will lower-case it when you refer to it using |
931 | \c{\\k}, and will leave it alone if you use \c{\\K}.) |
932 | |
933 | This technique allows you to change the designation of |
934 | \e{particular} sections. To make an overall change in what \e{every} |
935 | section is called, see \k{input-config}. |
936 | |
339cbe09 |
937 | Finally, the \c{\\U} command defines an \I{unnumbered |
938 | chapter}\e{unnumbered} chapter. These sometimes occur in books, for |
939 | specialist purposes such as \q{Bibliography} or |
940 | \q{Acknowledgements}. \c{\\U} does not expect a keyword argument, |
941 | because there is no sensible way to generate an automatic |
942 | cross-reference to such a chapter anyway. |
11f2edfa |
943 | |
8902e0ed |
944 | \S{input-blurb} \c{\\copyright}, \c{\\title}, \c{\\versionid}: |
339cbe09 |
945 | Miscellaneous \i{blurb commands} |
11f2edfa |
946 | |
339cbe09 |
947 | These three commands define a variety of \i{special paragraph |
948 | types}. They are all used in the same way: you put the command at |
949 | the start of a paragraph, and then just follow it with normal text, |
950 | like this: |
11f2edfa |
951 | |
952 | \c \title My First Manual |
953 | |
8902e0ed |
954 | The three special paragraph types are: |
11f2edfa |
955 | |
339cbe09 |
956 | \dt \i\cw{\\title} |
11f2edfa |
957 | |
958 | \dd This defines the overall title of the entire document. This |
959 | title is treated specially in some output formats (for example, it's |
960 | used in a \cw{<title>} tag in the HTML output), so it needs a |
961 | special paragraph type to point it out. |
962 | |
339cbe09 |
963 | \dt \i\cw{\\copyright} |
11f2edfa |
964 | |
965 | \dd This command indicates that the paragraph attached to it |
339cbe09 |
966 | contains a \i{copyright statement} for the document. This text is |
9057a0a8 |
967 | displayed inline where it appears, exactly like a normal paragraph; |
968 | but in some output formats it is given additional special treatment. |
969 | For example, Windows Help files have a standard slot in which to |
970 | store a copyright notice, so that other software can display it |
971 | prominently. |
11f2edfa |
972 | |
339cbe09 |
973 | \dt \i\cw{\\versionid} |
11f2edfa |
974 | |
975 | \dd This command indicates that the paragraph contains a version |
976 | identifier, such as those produced by CVS (of the form \c{$\#{hope this |
977 | defuses CVS}Id: thingy.but,v 1.6 2004/01/01 16:47:48 simon Exp $}). |
978 | This text will be tucked away somewhere unobtrusive, so that anyone |
979 | wanting to (for example) report errors to the document's author can |
339cbe09 |
980 | pick out the \i{version IDs} and send them as part of the report, so |
11f2edfa |
981 | that the author can tell at a glance which revision of the document |
982 | is being discussed. |
983 | |
339cbe09 |
984 | \S{input-commentpara} \i\c{\\#}: Whole-paragraph \i{comments} |
11f2edfa |
985 | |
986 | \K{input-inline-comment} describes the use of the \c{\\#} command to |
987 | put a short comment in the middle of a paragraph. |
988 | |
989 | If you need to use a \e{long} comment, Halibut also allows you to |
990 | use \c{\\#} without braces, to indicate that an entire paragraph is |
991 | a comment, like this: |
992 | |
993 | \c Here's a (fairly short) paragraph which will be displayed. |
994 | \c |
995 | \c \# Here's a comment paragraph which will not be displayed, no |
fc8e7adb |
996 | \c matter how long it goes on. All I needed to indicate this was |
997 | \c the single \# at the start of the paragraph; I don't need one |
998 | \c on every line or anything like that. |
11f2edfa |
999 | \c |
1000 | \c Here's another displayed paragraph. |
1001 | |
1002 | When run through Halibut, this produces the following output: |
1003 | |
1004 | \quote{ |
1005 | |
1006 | Here's a (fairly short) paragraph which will be displayed. |
1007 | |
1008 | \# Here's a comment paragraph which will not be displayed, no |
fc8e7adb |
1009 | matter how long it goes on. All I needed to indicate this was |
1010 | the single \# at the start of the paragraph; I don't need one |
1011 | on every line or anything like that. |
11f2edfa |
1012 | |
1013 | Here's another displayed paragraph. |
1014 | |
1015 | } |
1016 | |
339cbe09 |
1017 | \H{input-biblio} Creating a \i{bibliography} |
11f2edfa |
1018 | |
1019 | If you need your document to refer to other documents (research |
1020 | papers, books, websites, whatever), you might find a bibliography |
1021 | feature useful. |
1022 | |
da090173 |
1023 | You can define a bibliography entry using the \I{\\B-upper}\c{\\B} |
1024 | command. This looks very like the \c{\\C} command and friends: it |
1025 | expects a keyword in braces, followed by some text describing the |
1026 | document being referred to. For example: |
11f2edfa |
1027 | |
1028 | \c \B{freds-book} \q{The Taming Of The Mongoose}, by Fred Bloggs. |
1029 | \c Published by Paperjam & Notoner, 1993. |
1030 | |
1031 | If this bibliography entry appears in the finished document, it will |
1032 | look something like this: |
1033 | |
1034 | \quote{ |
1035 | |
1036 | \B{freds-book} \q{The Taming Of The Mongoose}, by Fred Bloggs. |
1037 | Published by Paperjam & Notoner, 1993. |
1038 | |
1039 | } |
1040 | |
1041 | I say \q{if} above because not all bibliography entries defined |
1042 | using the \c{\\B} command will necessarily appear in the finished |
339cbe09 |
1043 | document. They only appear if they are \I{citation}referred to by a |
1044 | \i\c{\\k} command (see \k{input-xref}). This allows you to (for |
1045 | example) maintain a single Halibut source file with a centralised |
1046 | database of \e{all} the references you have ever needed in any of |
1047 | your writings, include that file in every document you feed to |
1048 | Halibut, and have it only produce the bibliography entries you |
1049 | actually need for each particular document. (In fact, you might even |
1050 | want this centralised source file to be created automatically by, |
1051 | say, a Perl script from BibTeX input, so that you can share the same |
1052 | bibliography with users of other formatting software.) |
11f2edfa |
1053 | |
1054 | If you really want a bibliography entry to appear in the document |
1055 | even though no text explicitly refers to it, you can do that using |
339cbe09 |
1056 | the \i\c{\\nocite} command: |
11f2edfa |
1057 | |
1058 | \c \nocite{freds-book} |
1059 | |
1060 | Normally, each bibliography entry will be referred to (in citations |
1061 | and in the bibliography itself) by a simple reference number, such |
1062 | as \k{freds-book}. If you would rather use an alternative reference |
339cbe09 |
1063 | notation, such as [Fred1993], you can use the \i\c{\\BR} |
11f2edfa |
1064 | (\q{Bibliography Rewrite}) command to specify your own reference |
1065 | format for a particular book: |
1066 | |
1067 | \c \BR{freds-book} [Fred1993] |
1068 | |
acbb8b72 |
1069 | The keyword you supply after \c{\\B} is allowed to contain escaped |
1070 | special characters (\c{\\\\}, \c{\\\{} and \c{\\\}}), but should not |
1071 | contain any other Halibut markup. It is intended to be a word or two |
1072 | of ordinary text. (This also applies to keywords used in other |
1073 | commands, such as \c{\\n} and \c{\\C}). |
1074 | |
339cbe09 |
1075 | \H{input-index} Creating an \i{index} |
11f2edfa |
1076 | |
1077 | Halibut contains a comprehensive indexing mechanism, which attempts |
1078 | to be reasonably easy to use in the common case in spite of its |
1079 | power. |
1080 | |
1081 | \S{input-index-simple} Simple indexing |
1082 | |
1083 | In normal usage, you should be able to add index terms to your |
339cbe09 |
1084 | document simply by using the \i\c{\\i} command to wrap one or two |
11f2edfa |
1085 | words at a time. For example, if you write |
1086 | |
1087 | \c The \i{hippopotamus} is a particularly large animal. |
1088 | |
1089 | then the index will contain an entry under \q{hippopotamus}, |
1090 | pointing to that sentence (or as close to that sentence as the |
1091 | output format sensibly permits). |
1092 | |
1093 | You can wrap more than one word in \c{\\i} as well: |
1094 | |
1095 | \c We recommend using a \i{torque wrench} for this job. |
1096 | |
1097 | \S{input-index-special} Special cases of indexing |
1098 | |
1099 | If you need to index a computer-related term, you can use the |
339cbe09 |
1100 | special case \i\c{\\i\\c} (or \i\c{\\i\\cw} if you prefer): |
11f2edfa |
1101 | |
1102 | \c The \i\c{grep} command is what you want here. |
1103 | |
1104 | This will cause the word \q{grep} to appear in code style, as if the |
1105 | \c{\\i} were not present and the input just said \c{\\c\{grep\}}; |
1106 | the word will also appear in code style in the actual index. |
1107 | |
1108 | If you want to simultaneously index and emphasise a word, there's |
339cbe09 |
1109 | another special case \i\c{\\i\\e}: |
11f2edfa |
1110 | |
1111 | \c This is what we call a \i\e{paper jam}. |
1112 | |
1113 | This will cause the words \q{paper jam} to be emphasised in the |
1114 | document, but (unlike the behaviour of \c{\\i\\c}) they will \e{not} |
1115 | be emphasised in the index. This different behaviour is based on an |
1116 | expectation that most people indexing a word of computer code will |
1117 | still want it to look like code in the index, whereas most people |
1118 | indexing an emphasised word will \e{not} want it emphasised in the |
1119 | index. |
1120 | |
8856f150 |
1121 | (In fact, \e{no} emphasis in the text inside \c{\\i} will be |
1122 | preserved in the index. If you really want a term in the index to |
1123 | appear emphasised, you must say so explicitly using \c{\\IM}; see |
1124 | \k{input-index-rewrite}.) |
1125 | |
11f2edfa |
1126 | Sometimes you might want to index a term which is not explicitly |
1127 | mentioned, but which is highly relevant to the text and you think |
1128 | that somebody looking up that term in the index might find it useful |
da090173 |
1129 | to be directed here. To do this you can use the \I{\\I-upper}\c{\\I} |
1130 | command, to create an \i{\e{invisible} index tag}: |
11f2edfa |
1131 | |
1132 | \c If your printer runs out of toner, \I{replacing toner |
1133 | \c cartridge}here is what to do: |
1134 | |
1135 | This input will produce only the output \q{If your printer runs out |
1136 | of toner, here is what to do}; but an index entry will show up under |
1137 | \q{replacing toner cartridge}, so that if a user thinks the obvious |
1138 | place to start in the index is under R for \q{replacing}, they will |
1139 | find their way here with a minimum of fuss. |
1140 | |
1141 | (It's worth noting that there is no functional difference between |
1142 | \c{\\i\{foo\}} and \c{\\I\{foo\}foo}. The simple \c{\\i} case is |
1143 | only a shorthand for the latter.) |
1144 | |
1145 | Finally, if you want to index a word at the start of a sentence, you |
1146 | might very well not want it to show up with a capital letter in the |
339cbe09 |
1147 | index. For this, Halibut provides the \i\c{\\ii} command, for |
1148 | \q{index (case-)insensitively}. You use it like this: |
11f2edfa |
1149 | |
1150 | \c \ii{Lions} are at the top of the food chain in this area. |
1151 | |
1152 | This is equivalent to \c{\\I\{lions\}Lions}; in other words, the |
1153 | text will say \q{Lions}, but it will show up in the index as |
1154 | \q{lions}. The text inside \c{\\ii} is converted entirely into lower |
1155 | case before being added to the index data. |
1156 | |
339cbe09 |
1157 | \S{input-index-rewrite} \ii{Fine-tuning the index} |
11f2edfa |
1158 | |
1159 | Halibut's index mechanism as described so far still has a few |
1160 | problems left: |
1161 | |
1162 | \b In a reasonably large index, it's often difficult to predict |
339cbe09 |
1163 | \I{replicating index terms}which of several words a user will think |
1164 | of first when trying to look something up. For example, if they want |
1165 | to know how to replace a toner cartridge, they might look up |
1166 | \q{replacing} or they might look up \q{toner cartridge}. You |
1167 | probably don't really want to have to try to figure out which of |
1168 | those is more likely; instead, what you'd like is to be able to |
1169 | effortlessly index the same set of document locations under \e{both} |
1170 | terms. |
11f2edfa |
1171 | |
1172 | \b Also, you may find you've indexed the same concept under multiple |
339cbe09 |
1173 | different \I{merging index terms}index terms; for example, there |
1174 | might be several instances of \c{\\i\{frog\}} and several of |
1175 | \c{\\i\{frogs\}}, so that you'd end up with two separate index |
1176 | entries for what really ought to be the same concept. |
11f2edfa |
1177 | |
1178 | \b You might well not want the word \q{\cw{grep}} to appear in the |
1179 | index without explanation; you might prefer it to say something more |
339cbe09 |
1180 | \I{rewriting index terms}verbose such as \q{\cw{grep} command}, so |
1181 | that a user encountering it in the index has some idea of what it is |
1182 | \e{without} having to follow up the reference. However, you |
1183 | certainly don't want to have to write \c{\\I\{\\cw\{grep\} |
1184 | command\}\\c\{grep\}} every time you want to add an index term for |
1185 | this! You wanted to write \c{\\i\\c\{grep\}} as shown in the |
1186 | previous section, and tidy it all up afterwards. |
1187 | |
1188 | All of these problems can be cleaned up by the \i\c{\\IM} (for |
11f2edfa |
1189 | \q{Index Modification}) command. \c{\\IM} expects to be followed by |
1190 | one or more pairs of braces containing index terms as seen in the |
1191 | document, and then a piece of text (not in braces) describing how it |
1192 | should be shown in the index. |
1193 | |
1194 | So to rewrite the \c{grep} example above, you might do this: |
1195 | |
1196 | \c \IM{grep} \cw{grep} command |
1197 | |
1198 | This will arrange that the set of places in the document where you |
1199 | asked Halibut to index \q{\cw{grep}} will be listed under |
1200 | \q{\cw{grep} command} rather than just under \q{\cw{grep}}. |
1201 | |
1202 | You can specify more than one index term in a \c{\\IM} command; so |
1203 | to merge the index terms \q{frog} and \q{frogs} into a single term, |
1204 | you might do this: |
1205 | |
1206 | \c \IM{frog}{frogs} frog |
1207 | |
1208 | This will arrange that the single index entry \q{frog} will list |
1209 | \e{all} the places in the document where you asked Halibut to index |
1210 | either \q{frog} or \q{frogs}. |
1211 | |
1212 | You can use multiple \c{\\IM} commands to replicate the same set of |
1213 | document locations in more than one index entry. For example: |
1214 | |
1215 | \c \IM{replacing toner cartridge} replacing toner cartridge |
1216 | \c \IM{replacing toner cartridge} toner cartridge, replacing |
1217 | |
1218 | This will arrange that every place in the document where you have |
1219 | indexed \q{replacing toner cartridge} will be listed both there |
1220 | \e{and} under \q{toner cartridge, replacing}, so that no matter |
1221 | whether the user looks under R or under T they will stil find their |
1222 | way to the same parts of the document. |
1223 | |
1224 | In this example, note that although the first \c{\\IM} command |
1225 | \e{looks} as if it's a tautology, it is still necessary, because |
1226 | otherwise those document locations will \e{only} be indexed under |
1227 | \q{toner cartridge, replacing}. If you have \e{no} explicit \c{\\IM} |
1228 | commands for a particular index term, then Halibut will assume a |
1229 | default one (typically \c{\\IM\{foo\}\_foo}, although it might be |
1230 | \c{\\IM\{foo\}\_\\c\{foo\}} if you originally indexed using |
1231 | \c{\\i\\c}); but as soon as you specify an explicit \c{\\IM}, |
1232 | Halibut discards its default implicit one, and you must then specify |
1233 | that one explicitly as well if you wanted to keep it. |
1234 | |
da090173 |
1235 | \S{input-index-case} Indexing terms that differ only in case |
1236 | |
1237 | The \e{tags} you use to define an index term (that is, the text in |
1238 | the braces after \c{\\i}, \c{\\I} and \c{\\IM}) are treated |
1239 | case-insensitively by Halibut. So if, as in this manual itself, you |
1240 | need two index terms that differ only in case, doing this will not |
1241 | work: |
1242 | |
1243 | \c The \i\c{\\c} command defines computer code. |
1244 | \c |
1245 | \c The \i\c{\\C} command defines a chapter. |
1246 | |
1247 | Halibut will treat these terms as the same, and will fold the two |
1248 | sets of references into one combined list (although it will warn you |
1249 | that it is doing this). The idea is to ensure that people who forget |
1250 | to use \c{\\ii} find out about it rather than Halibut silently |
1251 | generating a bad index; checking an index for errors is very hard |
1252 | work, so Halibut tries to avoid errors in the first place as much as |
1253 | it can. |
1254 | |
1255 | If you do come across this situation, you will need to define two |
1256 | distinguishable index terms. What I did in this manual was something |
1257 | like this: |
1258 | |
1259 | \c The \i\c{\\c} command defines computer code. |
1260 | \c |
1261 | \c The \I{\\C-upper}\c{\\C} command defines a chapter. |
1262 | \c |
1263 | \c \IM{\\C-upper} \c{\\C} |
1264 | |
1265 | The effect of this will be two separate index entries, one reading |
1266 | \c{\\c} and the other reading \c{\\C}, pointing to the right places. |
1267 | |
339cbe09 |
1268 | \H{input-config} \ii{Configuring} Halibut |
11f2edfa |
1269 | |
339cbe09 |
1270 | Halibut uses the \i\c{\\cfg} command to allow you to configure various |
11f2edfa |
1271 | aspects of its functionality. |
1272 | |
1273 | The \c{\\cfg} command expects to be followed by at least one pair of |
1274 | braces, and usually more after that. The first pair of braces |
1275 | contains a keyword indicating what aspect of Halibut you want to |
1276 | configure, and the meaning of the one(s) after that depends on the |
1277 | first keyword. |
1278 | |
1279 | The current list of configuration keywords in the main Halibut code |
1280 | is quite small. Here it is in full: |
1281 | |
339cbe09 |
1282 | \dt \I\cw{\\cfg\{chapter\}}\cw{\\cfg\{chapter\}\{}\e{new chapter name}\cw{\}} |
11f2edfa |
1283 | |
1284 | \dd This tells Halibut that you don't want to call a chapter a |
339cbe09 |
1285 | \I{renaming sections}\I{configuring heading display}chapter any |
1286 | more. For example, if you give the command |
11f2edfa |
1287 | \cw{\\cfg\{chapter\}\{Book\}}, then any chapter defined with the |
1288 | \c{\\C} command will be labelled \q{Book} rather than \q{Chapter}, |
1289 | both in the section headings and in cross-references. This is |
1290 | probably most useful if your document is not written in English. |
1291 | |
339cbe09 |
1292 | \lcont{ |
1293 | |
1294 | Your replacement name should be given with a capital letter. Halibut |
1295 | will leave it alone if it appears at the start of a sentence (in a |
1296 | chapter title, or when \c{\\K} is used), and will lower-case it |
1297 | otherwise (when \c{\\k} is used). |
1298 | |
1299 | } |
1300 | |
1301 | \dt \I\cw{\\cfg\{section\}}\cw{\\cfg\{section\}\{}\e{new section name}\cw{\}} |
11f2edfa |
1302 | |
1303 | \dd Exactly like \c{chapter}, but changes the name given to |
1304 | subsections of a chapter. |
1305 | |
339cbe09 |
1306 | \dt \I\cw{\\cfg\{appendix\}}\cw{\\cfg\{appendix\}\{}\e{new appendix name}\cw{\}} |
11f2edfa |
1307 | |
339cbe09 |
1308 | \dd Exactly like \c{chapter}, but changes the name given to |
11f2edfa |
1309 | appendices. |
1310 | |
e34ba5c3 |
1311 | \dt \I\cw{\\cfg\{input-charset\}}\cw{\\cfg\{input-charset\}\{}\e{character set name}\cw{\}} |
1312 | |
1313 | \dd This tells Halibut what \i{character set} you are writing your |
1314 | input file in. By default, it is assumed to be US-ASCII (meaning |
1315 | \e{only} plain \i{ASCII}, with no accented characters at all). |
1316 | |
1317 | \lcont{ |
1318 | |
1319 | You can specify any well-known name for any supported character set. |
1320 | For example, \c{iso-8859-1}, \c{iso8859-1} and \c{iso_8859-1} are |
1321 | all recognised, \c{GB2312} and \c{EUC-CN} both work, and so on. |
1322 | |
1323 | This directive takes effect immediately after the \c{\\cfg} command. |
1324 | All text after that in the file is expected to be in the new |
1325 | character set. You can even change character set several times |
1326 | within a file if you really want to. |
1327 | |
1328 | When Halibut reads the input file, everything you type will be |
1329 | converted into \i{Unicode} from the character set you specify here, |
1330 | will be processed as Unicode by Halibut internally, and will be |
1331 | written to the various output formats in whatever character sets |
1332 | they deem appropriate. |
1333 | |
1334 | } |
1335 | |
11f2edfa |
1336 | In addition to these configuration commands, there are also |
1337 | configuration commands provided by each individual output format. |
1338 | These configuration commands are discussed along with each output |
16ea3abe |
1339 | format, in \k{output}. |
11f2edfa |
1340 | |
339cbe09 |
1341 | The \i{default settings} for the above options are: |
1342 | |
1343 | \c \cfg{chapter}{Chapter} |
1344 | \c \cfg{section}{Section} |
1345 | \c \cfg{appendix}{Appendix} |
60f49347 |
1346 | \c \cfg{input-charset}{ASCII} |
339cbe09 |
1347 | |
1348 | \H{input-macro} Defining \i{macros} |
11f2edfa |
1349 | |
1350 | If there's a complicated piece of Halibut source which you think |
1351 | you're going to use a lot, you can define your own Halibut command |
1352 | to produce that piece of source. |
1353 | |
1354 | In \k{input-unicode}, there is a sample piece of code which prints a |
1355 | Euro sign, or replaces it with \q{EUR} if the Euro sign is not |
1356 | available: |
1357 | |
16ea3abe |
1358 | \c This is likely to cost \u20AC{EUR\_}2500 at least. |
11f2edfa |
1359 | |
1360 | If your document quotes a \e{lot} of prices in Euros, you might not |
1361 | want to spend all your time typing that out. So you could define a |
339cbe09 |
1362 | macro, using the \i\c{\\define} command: |
11f2edfa |
1363 | |
16ea3abe |
1364 | \c \define{eur} \u20AC{EUR\_} |
11f2edfa |
1365 | |
acbb8b72 |
1366 | Your macro names may include Roman alphabetic characters |
1367 | (\c{a}-\c{z}, \c{A}-\c{Z}) and ordinary Arabic numerals |
1368 | (\c{0}-\c{9}), but nothing else. (This is general \I{command |
1369 | syntax}syntax for all of Halibut's commands, except for a few |
1370 | special ones such as \c{\\_} and \c{\\-} which consist of a single |
1371 | punctuation character only.) |
1372 | |
672e4626 |
1373 | Then you can just write ... |
11f2edfa |
1374 | |
1375 | \c This is likely to cost \eur 2500 at least. |
1376 | |
672e4626 |
1377 | ... except that that's not terribly good, because you end up with a |
acbb8b72 |
1378 | space between the Euro sign and the number. (If you had written |
1379 | \c{\\eur2500}, Halibut would have tried to interpret it as a macro |
1380 | command called \c{eur2500}, which you didn't define.) In this case, |
1381 | it's helpful to use the special \i\c{\\.} command, which is defined |
1382 | to \I{NOP}\I{doing nothing}do nothing at all! But it acts as a |
339cbe09 |
1383 | separator between your macro and the next character: |
672e4626 |
1384 | |
1385 | \c This is likely to cost \eur\.2500 at least. |
1386 | |
1387 | This way, you will see no space between the Euro sign and the number |
1388 | (although, of course, there will be space between \q{EUR} and the |
1389 | number if the Euro sign is not available, because the macro |
1390 | definition specifically asked for it). |