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