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  27. <body bgcolor=white>
    28. 

  28. 

  29. <h2>CL-PPCRE - Portable Perl-compatible regular expressions for Common Lisp</h2>
    30. 

  30. 

  31. <blockquote>
    32. 

  32. <br>&nbsp;<br><h3>Abstract</h3>
    33. 

  33. 

  34. CL-PPCRE is a portable regular expression library for Common Lisp
    35. 

  35. which has the following features:
    36. 

  36. 

  37. <ul>
    38. 

  38. 

  39. <li>It is <b>compatible with Perl</b>.
    40. 

  40. 

  41. <li>It is pretty <b>fast</b>.
    42. 

  42. 

  43. <li>It is <b>portable</b> between ANSI-compliant Common Lisp
    44. 

  44. implementations.
    45. 

  45. 

  46. <li>It is <b>thread-safe</b>.
    47. 

  47. 

  48. <li>In addition to specifying regular expressions as strings like in
    49. 

  49. Perl you can also use <a
    50. 

  50. href="#create-scanner2"><b>S-expressions</b></a>.
    51. 

  51. 

  52. <li>It comes with a <a
    53. 

  53. href="http://www.opensource.org/licenses/bsd-license.php"><b>BSD-style
    54. 

  54. license</b></a> so you can basically do with it whatever you want.
    55. 

  55. 

  56. </ul>
    57. 

  57. 

  58. CL-PPCRE has been used successfully in various applications like <a
    59. 

  59. href="http://nostoc.stanford.edu/Docs/">BioBike</a>, 
    60. 

  60. <a href="http://clutu.com/">clutu</a>,
    61. 

  61. <a
    62. 

  62. href="http://www.hpc.unm.edu/~download/LoGS/">LoGS</a>, <a href="http://cafespot.net/">CafeSpot</a>, <a href="http://www.eboy.com/">Eboy</a>, or <a
    63. 

  63. href="http://weitz.de/regex-coach/">The Regex Coach</a>.
    64. 

  64. 

  65. <p>
    66. 

  66. <font color=red>Download shortcut:</font> <a href="http://weitz.de/files/cl-ppcre.tar.gz">http://weitz.de/files/cl-ppcre.tar.gz</a>.
    67. 

  67. 

  68. </blockquote>
    69. 

  69. 

  70. <br>&nbsp;<br><h3><a class=none name="contents">Contents</a></h3>
    71. 

  71. <ol>
    72. 

  72.   <li><a href="#install">Download and installation</a>
    73. 

  73.   <li><a href="#support">Support</a>
    74. 

  74.   <li><a href="#dict">The CL-PPCRE dictionary</a>
    75. 

  75.   <ol>
    76. 

  76.     <li><a href="#scanning">Scanning</a>
    77. 

  77.     <ol>
    78. 

  78.       <li><a href="#create-scanner"><code>create-scanner</code></a> (for Perl regex strings)
    79. 

  79.       <li><a href="#create-scanner2"><code>create-scanner</code></a> (for parse trees)
    80. 

  80.       <li><a href="#scan"><code>scan</code></a>
    81. 

  81.       <li><a href="#scan-to-strings"><code>scan-to-strings</code></a>
    82. 

  82.       <li><a href="#register-groups-bind"><code>register-groups-bind</code></a>
    83. 

  83.       <li><a href="#do-scans"><code>do-scans</code></a>
    84. 

  84.       <li><a href="#do-matches"><code>do-matches</code></a>
    85. 

  85.       <li><a href="#do-matches-as-strings"><code>do-matches-as-strings</code></a>
    86. 

  86.       <li><a href="#do-register-groups"><code>do-register-groups</code></a>
    87. 

  87.       <li><a href="#all-matches"><code>all-matches</code></a>
    88. 

  88.       <li><a href="#all-matches-as-strings"><code>all-matches-as-strings</code></a>
    89. 

  89.     </ol>
    90. 

  90.     <li><a href="#splitting">Splitting and replacing</a>
    91. 

  91.     <ol>
    92. 

  92.       <li><a href="#split"><code>split</code></a>
    93. 

  93.       <li><a href="#regex-replace"><code>regex-replace</code></a>
    94. 

  94.       <li><a href="#regex-replace-all"><code>regex-replace-all</code></a>
    95. 

  95.     </ol>
    96. 

  96.     <li><a href="#modify">Modifying scanner behaviour</a>
    97. 

  97.     <ol>
    98. 

  98.       <li><a href="#*property-resolver*"><code>*property-resolver*</code></a>
    99. 

  99.       <li><a href="#parse-tree-synonym"><code>parse-tree-synonym</code></a>
    100. 

  100.       <li><a href="#define-parse-tree-synonym"><code>define-parse-tree-synonym</code></a>
    101. 

  101.       <li><a href="#*regex-char-code-limit*"><code>*regex-char-code-limit*</code></a>
    102. 

  102.       <li><a href="#*use-bmh-matchers*"><code>*use-bmh-matchers*</code></a>
    103. 

  103.       <li><a href="#*optimize-char-classes*"><code>*optimize-char-classes*</code></a>
    104. 

  104.       <li><a href="#*allow-quoting*"><code>*allow-quoting*</code></a>
    105. 

  105.       <li><a href="#*allow-named-registers*"><code>*allow-named-registers*</code></a>
    106. 

  106.     </ol>
    107. 

  107.     <li><a href="#misc">Miscellaneous</a>
    108. 

  108.     <ol>
    109. 

  109.       <li><a href="#parse-string"><code>parse-string</code></a>
    110. 

  110.       <li><a href="#create-optimized-test-function"><code>create-optimized-test-function</code></a>
    111. 

  111.       <li><a href="#quote-meta-chars"><code>quote-meta-chars</code></a>
    112. 

  112.       <li><a href="#regex-apropos"><code>regex-apropos</code></a>
    113. 

  113.       <li><a href="#regex-apropos-list"><code>regex-apropos-list</code></a>
    114. 

  114.     </ol>
    115. 

  115.     <li><a href="#conditions">Conditions</a>
    116. 

  116.     <ol>
    117. 

  117.       <li><a href="#ppcre-error"><code>ppcre-error</code></a>
    118. 

  118.       <li><a href="#ppcre-invocation-error"><code>ppcre-invocation-error</code></a>
    119. 

  119.       <li><a href="#ppcre-syntax-error"><code>ppcre-syntax-error</code></a>
    120. 

  120.       <li><a href="#ppcre-syntax-error-string"><code>ppcre-syntax-error-string</code></a>
    121. 

  121.       <li><a href="#ppcre-syntax-error-pos"><code>ppcre-syntax-error-pos</code></a>
    122. 

  122.     </ol>
    123. 

  123.   </ol>
    124. 

  124.   <li><a href="#unicode">Unicode properties</a>
    125. 

  125.   <ol>
    126. 

  126.       <li><a href="#unicode-property-resolver"><code>unicode-property-resolver</code></a>
    127. 

  127.   </ol>
    128. 

  128.   <li><a href="#filters">Filters</a>
    129. 

  129.   <li><a href="#perl">Compatibility with Perl</a>
    130. 

  130.     <ol>
    131. 

  131.       <li><a href="#empty">Empty strings instead of <code>undef</code> in <code>$1</code>, <code>$2</code>, etc.</a>
    132. 

  132.       <li><a href="#scope">Strange scoping of embedded modifiers</a>
    133. 

  133.       <li><a href="#inconsistent">Inconsistent capturing of <code>$1</code>, <code>$2</code>, etc.</a>
    134. 

  134.       <li><a href="#lookaround">Captured groups not available outside of look-aheads and look-behinds</a>
    135. 

  135.       <li><a href="#order">Alternations don't always work from left to right</a>
    136. 

  136.       <li><a href="#uprops">Different names for Unicode properties</a>
    137. 

  137.       <li><a href="#mac"><code>&quot;\r&quot;</code> doesn't work with MCL</a>
    138. 

  138.       <li><a href="#alpha">What about <code>&quot;\w&quot;</code>?</a>
    139. 

  139.     </ol>
    140. 

  140.   <li><a href="#bugs">Bugs and problems</a>
    141. 

  141.   <ol>
    142. 

  142.     <li><a href="#quote"><code>&quot;\Q&quot;</code> doesn't work, or does it?</a>
    143. 

  143.     <li><a href="#backslash">Backslashes may confuse you...</a>
    144. 

  144.   </ol>
    145. 

  145.   <li><a href="#allegro">AllegroCL compatibility mode</a>
    146. 

  146.   <li><a href="#blabla">Hints, comments, performance considerations</a>
    147. 

  147.   <li><a href="#ack">Acknowledgements</a>
    148. 

  148. </ol>
    149. 

  149. 

  150. <br>&nbsp;<br><h3><a name="install" class=none>Download and installation</a></h3>
    151. 

  151. 

  152. CL-PPCRE together with this documentation can be downloaded from <a
    153. 

  153. href="http://weitz.de/files/cl-ppcre.tar.gz">http://weitz.de/files/cl-ppcre.tar.gz</a>. The
    154. 

  154. current version is 2.0.11.
    155. 

  155. <p>
    156. 

  156. CL-PPCRE comes with a system definition
    157. 

  157. for <a href="http://www.cliki.net/asdf">ASDF</a> and you compile and
    158. 

  158. load it in the usual way.  There are no dependencies (except that the
    159. 

  159. <a href="#test">test suite</a> which is not needed for normal operation depends
    160. 

  160. on <a href="http://weitz.de/flexi-streams/">FLEXI-STREAMS</a>).
    161. 

  161. <p>
    162. 

  162.   The preferred way to install CL-PPCRE is
    163. 

  163. through <a href="http://www.quicklisp.org/" target="_new">Quicklisp</a>:
    164. 

  164.   <pre>(ql:quickload :cl-ppcre)</pre>
    165. 

  165. </p>
    166. 

  166. <p>
    167. 

  167. <a class=none name="test">You</a> can run a test suite which tests most aspects of the library with
    168. 

  168. <pre>
    169. 

  169. (asdf:oos 'asdf:test-op :cl-ppcre)
    170. 

  170. </pre>
    171. 

  171. <p>
    172. 

  172. The current development version of CL-PPCRE can be found
    173. 

  173. at <a href="https://github.com/edicl/cl-ppcre">https://github.com/edicl/cl-ppcre</a>. If you want to send patches, please fork the github repository and send pull requests. 
    174. 

  174. <p>
    175. 

  175. 

  176. <br>&nbsp;<br><h3><a name="support" class=none>Support</a></h3>
    177. 

  177. 

  178. The development version of cl-ppcre can be
    179. 

  179. found <a href="https://github.com/edicl/cl-ppcre" target="_new">on
    180. 

  180. github</a>.  Please use the github issue tracking system to submit bug
    181. 

  181. reports.  Patches are welcome, please
    182. 

  182. use <a href="https://github.com/edicl/cl-ppcre/pulls">GitHub pull
    183. 

  183. requests</a>.  If you want to make a change,
    184. 

  184. please <a href="http://weitz.de/patches.html" target="_new">read this
    185. 

  185. first</a>.
    186. 

  186. 

  187. <br>&nbsp;<br><h3><a class=none name="dict">The CL-PPCRE dictionary</a></h3>
    188. 

  188. 

  189. <h4><a name="scanning" class=none>Scanning</a></h4>
    190. 

  190. 

  191. <p><br>[Method]
    192. 

  192. <br><a class=none name="create-scanner"><b>create-scanner</b> <i>(string string)<tt>&amp;key</tt> case-insensitive-mode multi-line-mode single-line-mode extended-mode destructive</i> =&gt; <i>scanner, register-names</i></a>
    193. 

  193. 

  194. <blockquote><br> Accepts a string which is a regular expression in
    195. 

  195. Perl syntax and returns a closure which will scan strings for this
    196. 

  196. regular expression. The second value is only returned if <a href="#*allow-named-registers*"><code>*ALLOW-NAMED-REGISTERS*</code></a> is <i>true</i>. It represents a list of strings mapping registers to their respective names - the first element stands for first register, the second element for second register, etc. You have to store this value if you want to map a register number to its name later as <i>scanner</i> doesn't capture any information about register names. If a register isn't named, it has NIL as its name.
    197. 

  197. <p>
    198. 

  198. The mode keyword arguments are equivalent to the
    199. 

  199. <code>&quot;imsx&quot;</code> modifiers in Perl. The
    200. 

  200. <code>destructive</code> keyword will be ignored.
    201. 

  201. <p>
    202. 

  202. The function accepts most of the regex syntax of Perl 5.8 as described
    203. 

  203. in <a href="http://perldoc.perl.org/5.8.8/perlre.html"><code>man
    204. 

  204. perlre</code></a> including extended features like non-greedy
    205. 

  205. repetitions, positive and negative look-ahead and look-behind
    206. 

  206. assertions, &quot;standalone&quot; subexpressions, and conditional
    207. 

  207. subpatterns. The following Perl features are (currently) <b>not</b>
    208. 

  208. supported:
    209. 

  209. 

  210. <ul>
    211. 

  211. 

  212. <li><code>(?{ code })</code> and <code>(??{ code })</code> because
    213. 

  213. they obviously don't make sense in Lisp.
    214. 

    215. 

  215. <li><code>\N{name}</code> (named characters), <code>\x{263a}</code>
    216. 

  216. (wide hex characters), <code>\l</code>, <code>\u</code>,
    217. 

  217. <code>\L</code>, and <code>\U</code>
    218. 

  218. because they're actually not part of Perl's <em>regex</em> syntax - but see <a href="http://weitz.de/cl-interpol/">CL-INTERPOL</a>.
    219. 

  219. 

  220. <li><code>\X</code> (extended Unicode), and <code>\C</code> (single
    221. 

  221. character). But you can of course use all characters
    222. 

  222. supported by your CL implementation.
    223. 

  223. 

  224. <li>Posix character classes like <code>[[:alpha]]</code>.
    225. 

  225. Use <a href="#unicode">Unicode properties</a> instead.
    226. 

  226. 

  227. <li><code>\G</code> for Perl's <code>pos()</code> because we don't have it.
    228. 

  228. 

  229. </ul>
    230. 

  230. 

  231. Note, however, that <code>\t</code>, <code>\n</code>, <code>\r</code>,
    232. 

  232. <code>\f</code>, <code>\a</code>, <code>\e</code>, <code>\033</code>
    233. 

  233. (octal character codes), <code>\x1B</code> (hexadecimal character
    234. 

  234. codes), <code>\c[</code> (control characters), <code>\w</code>,
    235. 

  235. <code>\W</code>, <code>\s</code>, <code>\S</code>, <code>\d</code>,
    236. 

  236. <code>\D</code>, <code>\b</code>, <code>\B</code>, <code>\A</code>,
    237. 

  237. <code>\Z</code>, and <code>\z</code> <b>are</b> supported.
    238. 

  238. <p>
    239. 

  239. Since version 0.6.0, CL-PPCRE also supports Perl's <code>\Q</code> and <code>\E</code> - see <a
    240. 

  240. href="#*allow-quoting*"><code>*ALLOW-QUOTING*</code></a> below. Make sure you also read <a href="#quote">the relevant section</a> in &quot;<a href="#bugs">Bugs and problems</a>.&quot;
    241. 

  241. <p>
    242. 

  242. Since version 1.3.0, CL-PPCRE offers support for <a href="http://www.franz.com/support/documentation/7.0/doc/regexp.htm#regexp-new-capturing-2">AllegroCL's</a> <code>(?&lt;name&gt;"&lt;regex&gt;")</code>  named registers and <code>\k&lt;name&gt;</code> back-references syntax, have a look at <a href="#*allow-named-registers*"><code>*ALLOW-NAMED-REGISTERS*</code></a> for details.
    243. 

  243. <p>
    244. 

  244. Since version 2.0.0, CL-PPCRE
    245. 

  245. supports <a href="#*property-resolver*">named properties</a>
    246. 

  246. (<code>\p</code> and <code>\P</code>), but only the long form with
    247. 

  247. braces is supported, i.e. <code>\p{Letter}</code>
    248. 

  248. and <code>\p{L}</code> will work while <code>\pL</code> won't.
    249. 

  249. <p>
    250. 

  250. The keyword arguments are just for your
    251. 

  251. convenience. You can always use embedded modifiers like
    252. 

  252. <code>&quot;(?i-s)&quot;</code> instead.</blockquote>
    253. 

  253. 

  254. <p><br>[Method]
    255. 

  255. <br><a class=none name="create-scanner"><b>create-scanner</b> <i>(function function)<tt>&amp;key</tt> case-insensitive-mode multi-line-mode single-line-mode extended-mode destructive</i> =&gt; <i>scanner</i></a>
    256. 

  256. <blockquote><br> In this case <code><i>function</i></code> should be a
    257. 

  257. scanner returned by another invocation
    258. 

  258. of <code>CREATE-SCANNER</code>. It will be returned as is.  You can't
    259. 

  259. use any of the keyword arguments because the scanner has already been
    260. 

  260. created and is immutable.
    261. 

  261. </blockquote>
    262. 

  262. 

  263. <p><br>[Method]
    264. 

  264. <br><a class=none name="create-scanner2"><b>create-scanner</b> <i>(parse-tree t)<tt>&amp;key</tt> case-insensitive-mode multi-line-mode single-line-mode extended-mode destructive</i> =&gt; <i>scanner, register-names</i></a>
    265. 

  265. <blockquote><br>
    266. 

  266. This is similar to <a
    267. 

  267. href="#create-scanner"><code>CREATE-SCANNER</code></a> for regex strings above but
    268. 

  268. accepts a <em>parse tree</em> as its first argument. A parse tree is an S-expression
    269. 

  269. conforming to the following syntax:
    270. 

  270. 

  271. <ul>
    272. 

  272. 

  273. <li>Every string and character is a parse tree and is treated
    274. 

  274. <em>literally</em> as a part of the regular expression,
    275. 

  275. i.e. parentheses, brackets, asterisks and such aren't special.
    276. 

    277. 

  277. <li>The symbol <code>:VOID</code> is equivalent to the empty string.
    278. 

  278. 

  279. <li>The symbol <code>:EVERYTHING</code> is equivalent to Perl's dot,
    280. 

  280. i.e it matches everything (except maybe a newline character depending
    281. 

  281. on the mode).
    282. 

  282. 

  283. <li>The symbols <code>:WORD-BOUNDARY</code> and
    284. 

  284. <code>:NON-WORD-BOUNDARY</code> are equivalent to Perl's
    285. 

  285. <code>&quot;\b&quot;</code> and <code>&quot;\B&quot;</code>.
    286. 

  286. 

  287. <li>The symbols <code>:DIGIT-CLASS</code>,
    288. 

  288. <code>:NON-DIGIT-CLASS</code>, <code>:WORD-CHAR-CLASS</code>,
    289. 

  289. <code>:NON-WORD-CHAR-CLASS</code>,
    290. 

  290. <code>:WHITESPACE-CHAR-CLASS</code>, and
    291. 

  291. <code>:NON-WHITESPACE-CHAR-CLASS</code> are equivalent to Perl's
    292. 

  292. <em>special character classes</em> <code>&quot;\d&quot;</code>,
    293. 

  293. <code>&quot;\D&quot;</code>, <code>&quot;\w&quot;</code>,
    294. 

  294. <code>&quot;\W&quot;</code>, <code>&quot;\s&quot;</code>, and
    295. 

  295. <code>&quot;\S&quot;</code> respectively.
    296. 

  296. 

  297. <li>The symbols <code>:START-ANCHOR</code>, <code>:END-ANCHOR</code>,
    298. 

  298. <code>:MODELESS-START-ANCHOR</code>,
    299. 

  299. <code>:MODELESS-END-ANCHOR</code>, and
    300. 

  300. <code>:MODELESS-END-ANCHOR-NO-NEWLINE</code> are equivalent to Perl's
    301. 

  301. <code>&quot;^&quot;</code>, <code>&quot;$&quot;</code>,
    302. 

  302. <code>&quot;\A&quot;</code>, <code>&quot;\Z&quot;</code>, and
    303. 

  303. <code>&quot;\z&quot;</code> respectively.
    304. 

  304. 

  305. <li>The symbols <code>:CASE-INSENSITIVE-P</code>,
    306. 

  306. <code>:CASE-SENSITIVE-P</code>, <code>:MULTI-LINE-MODE-P</code>,
    307. 

  307. <code>:NOT-MULTI-LINE-MODE-P</code>, <code>:SINGLE-LINE-MODE-P</code>,
    308. 

  308. and <code>:NOT-SINGLE-LINE-MODE-P</code> are equivalent to Perl's
    309. 

  309. <em>embedded modifiers</em> <code>&quot;(?i)&quot;</code>,
    310. 

  310. <code>&quot;(?-i)&quot;</code>, <code>&quot;(?m)&quot;</code>,
    311. 

  311. <code>&quot;(?-m)&quot;</code>, <code>&quot;(?s)&quot;</code>, and
    312. 

  312. <code>&quot;(?-s)&quot;</code>. As usual, changes applied to modes are
    313. 

  313. kept local to the innermost enclosing grouping or clustering
    314. 

  314. construct.
    315. 

  315. 

  316. </li><li>All other symbols will signal an error of type <a
    317. 

  317. href="#ppcre-syntax-error"><code>PPCRE-SYNTAX-ERROR</code></a>
    318. 

  318. <em>unless</em> they are defined to be <a
    319. 

  319. href="#parse-tree-synonym"><em>parse tree synonyms</em></a>.
    320. 

  320. 

  321. <li><code>(:FLAGS {&lt;modifier&gt;}*)</code> where
    322. 

  322. <code>&lt;modifier&gt;</code> is one of the modifier symbols from
    323. 

  323. above is used to group modifier symbols. The modifiers are applied
    324. 

  324. from left to right. (This construct is obviously redundant. It is only
    325. 

  325. there because it's used by the parser.)
    326. 

    327. 

  327. <li><code>(:SEQUENCE {&lt;<i>parse-tree</i>&gt;}*)</code> means a
    328. 

  328. sequence of parse trees, i.e. the parse trees must match one after
    329. 

  329. another. Example: <code>(:SEQUENCE #\f #\o #\o)</code> is equivalent
    330. 

  330. to the parse tree <code>&quot;foo&quot;</code>.
    331. 

  331. 

  332. <li><code>(:GROUP {&lt;<i>parse-tree</i>&gt;}*)</code> is like
    333. 

  333. <code>:SEQUENCE</code> but changes applied to modifier flags (see
    334. 

  334. above) are kept local to the parse trees enclosed by this
    335. 

  335. construct. Think of it as the S-expression variant of Perl's
    336. 

  336. <code>&quot;(?:&lt;<i>pattern</i>&gt;)&quot;</code> construct.
    337. 

  337. 

  338. <li><code>(:ALTERNATION {&lt;<i>parse-tree</i>&gt;}*)</code> means an
    339. 

  339. alternation of parse trees, i.e. one of the parse trees must
    340. 

  340. match. Example: <code>(:ALTERNATION #\b #\a #\z)</code> is equivalent
    341. 

  341. to the Perl regex string <code>&quot;b|a|z&quot;</code>.
    342. 

  342. 

  343. <li><code>(:BRANCH &lt;<i>test</i>&gt;
    344. 

  344. &lt;<i>parse-tree</i>&gt;)</code> is for conditional regular
    345. 

  345. expressions. <code>&lt;<i>test</i>&gt;</code> is either a number which
    346. 

  346. stands for a register or a parse tree which is a look-ahead or
    347. 

  347. look-behind assertion. See the entry for
    348. 

  348. <code>(?(&lt;<i>condition</i>&gt;)&lt;<i>yes-pattern</i>&gt;|&lt;<i>no-pattern</i>&gt;)</code>
    349. 

  349. in <a
    350. 

  350. href="http://perldoc.perl.org/perlre.html#Extended-Patterns"><code>man
    351. 

  351. perlre</code></a> for the semantics of this construct. If
    352. 

  352. <code>&lt;<i>parse-tree</i>&gt;</code> is an alternation is
    353. 

  353. <em>must</em> enclose exactly one or two parse trees where the second
    354. 

  354. one (if present) will be treated as the &quot;no-pattern&quot; - in
    355. 

  355. all other cases <code>&lt;<i>parse-tree</i>&gt;</code> will be treated
    356. 

  356. as the &quot;yes-pattern&quot;.
    357. 

  357. 

  358. <li><code>(:POSITIVE-LOOKAHEAD|:NEGATIVE-LOOKAHEAD|:POSITIVE-LOOKBEHIND|:NEGATIVE-LOOKBEHIND
    359. 

  359. &lt;<i>parse-tree</i>&gt;)</code> should be pretty obvious...
    360. 

  360. 

  361. <li><code>(:GREEDY-REPETITION|:NON-GREEDY-REPETITION
    362. 

  362. &lt;<i>min</i>&gt; &lt;<i>max</i>&gt;
    363. 

  363. &lt;<i>parse-tree</i>&gt;)</code> where
    364. 

  364. <code>&lt;<i>min</i>&gt;</code> is a non-negative integer and
    365. 

  365. <code>&lt;<i>max</i>&gt;</code> is either a non-negative integer not
    366. 

  366. smaller than <code>&lt;<i>min</i>&gt;</code> or <code>NIL</code> will
    367. 

  367. result in a regular expression which tries to match
    368. 

  368. <code>&lt;<i>parse-tree</i>&gt;</code> at least
    369. 

  369. <code>&lt;<i>min</i>&gt;</code> times and at most
    370. 

  370. <code>&lt;<i>max</i>&gt;</code> times (or as often as possible if
    371. 

  371. <code>&lt;<i>max</i>&gt;</code> is <code>NIL</code>). So, e.g.,
    372. 

  372. <code>(:NON-GREEDY-REPETITION 0 1 &quot;ab&quot;)</code> is equivalent
    373. 

  373. to the Perl regex string <code>&quot;(?:ab)??&quot;</code>.
    374. 

  374. 

  375. <li><code>(:STANDALONE &lt;<i>parse-tree</i>&gt;)</code> is an
    376. 

  376. &quot;independent&quot; subexpression, i.e. <code>(:STANDALONE
    377. 

  377. &quot;bar&quot;)</code> is equivalent to the Perl regex string
    378. 

  378. <code>&quot;(?>bar)&quot;</code>.
    379. 

  379. 

  380. <li><code>(:REGISTER &lt;<i>parse-tree</i>&gt;)</code> is a capturing
    381. 

  381. register group. As usual, registers are counted from left to right
    382. 

  382. beginning with 1.
    383. 

  383. 

  384. <li><code>(:NAMED-REGISTER &lt;<i>name</i>&gt; &lt;<i>parse-tree</i>&gt;)</code> is a named capturing
    385. 

  385. register group. Acts as <code>:REGISTER</code>, but assigns <code>&lt;<i>name</i>&gt;</code> to a register too. This <code>&lt;<i>name</i>&gt;</code> can be later referred to via <code>:BACK-REFERENCE</code>. Names are case-sensitive and don't need to be unique. See <a href="#*allow-named-registers*"><code>*ALLOW-NAMED-REGISTERS*</code></a> for details.
    386. 

    387. 

  387. 

  388. <li><code>(:BACK-REFERENCE &lt;<i>ref</i>&gt;)</code> is a
    389. 

  389. back-reference to a register group. <code>&lt;<i>ref</i>&gt;</code> is
    390. 

  390. a positive integer or a string denoting a register name. If there are
    391. 

  391. several registers with the same name, the regex engine tries to
    392. 

  392. successfully match at least of them, starting with the most recently
    393. 

  393. seen register continuing to the least recently seen one, until a match
    394. 

  394. is found. See <a
    395. 

  395. href="#*allow-named-registers*"><code>*ALLOW-NAMED-REGISTERS*</code></a>
    396. 

  396. for more information.
    397. 

  397. 

  398. <li><code>(:PROPERTY|:INVERTED-PROPERTY &lt;<i>property</i>&gt;)</code> is
    399. 

  399. a <a href="#*property-resolver*">named property</a> (or its inverse) with
    400. 

  400. <code>&lt;<i>property</i>&gt;</code> being a function designator or a
    401. 

  401. string which must be resolved
    402. 

  402. by <a href="#*property-resolver*"><code>*PROPERTY-RESOLVER*</code></a>.
    403. 

  403. 

  404. <li><a class=none name="filterdef"><code>(:FILTER &lt;<i>function</i>&gt; <tt>&amp;optional</tt>
    405. 

  405. &lt;<i>length</i>&gt;)</code></a> where
    406. 

  406. <code>&lt;<i>function</i>&gt;</code> is a <a
    407. 

  407. href="http://www.lispworks.com/documentation/HyperSpec/Body/26_glo_f.htm#function_designator">function
    408. 

  408. designator</a> and <code>&lt;<i>length</i>&gt;</code> is a
    409. 

  409. non-negative integer or <code>NIL</code> is a user-defined <a
    410. 

  410. href="#filters">filter</a>.
    411. 

  411. 

  412. <li><code>(:REGEX &lt;<i>string</i>&gt;)</code> where
    413. 

  413. <code>&lt;<i>string</i>&gt;</code> is an
    414. 

  414. embedded <a href="#create-scanner">regular expression in Perl
    415. 

  415. syntax</a>.
    416. 

  416. 

  417. <li><code>(:CHAR-CLASS|:INVERTED-CHAR-CLASS
    418. 

  418. {&lt;<i>item</i>&gt;}*)</code> where <code>&lt;<i>item</i>&gt;</code>
    419. 

  419. is either a character, a <em>character range</em>, a named property
    420. 

  420. (see above), or a symbol for a special character class (see above)
    421. 

  421. will be translated into a (one character wide) character
    422. 

  422. class. A <em>character range</em> looks like
    423. 

  423. <code>(:RANGE &lt;<i>char1</i>&gt; &lt;<i>char2</i>&gt;)</code> where
    424. 

  424. <code>&lt;<i>char1</i>&gt;</code> and
    425. 

  425. <code>&lt;<i>char2</i>&gt;</code> are characters such that
    426. 

  426. <code>(CHAR&lt;= &lt;<i>char1</i>&gt; &lt;<i>char2</i>&gt;)</code> is
    427. 

  427. true. Example: <code>(:INVERTED-CHAR-CLASS #\a (:RANGE #\D #\G)
    428. 

  428. :DIGIT-CLASS)</code> is equivalent to the Perl regex string
    429. 

  429. <code>&quot;[^aD-G\d]&quot;</code>.
    430. 

  430. 

  431. </ul>
    432. 

  432. 

  433. Because <code>CREATE-SCANNER</code> is defined as a generic function
    434. 

  434. which dispatches on its first argument there's a certain ambiguity:
    435. 

  435. Although strings are valid parse trees they will be interpreted as
    436. 

  436. Perl regex strings when given to <code>CREATE-SCANNER</code>. To
    437. 

  437. circumvent this you can always use the equivalent parse tree <code>(:GROUP
    438. 

  438. &lt;<i>string</i>&gt;)</code> instead.
    439. 

  439. <p>
    440. 

  440. Note that <code>CREATE-SCANNER</code> doesn't always check
    441. 

  441. for the well-formedness of its first argument, i.e. you are expected
    442. 

  442. to provide <em>correct</em> parse trees.
    443. 

  443. 

  444. <p>
    445. 

  445. The usage of the keyword argument <code>extended-mode</code> obviously
    446. 

  446. doesn't make sense if <code>CREATE-SCANNER</code> is applied to parse
    447. 

  447. trees and will signal an error.
    448. 

  448. <p>
    449. 

  449. If <code>destructive</code> is not <code>NIL</code> (the default is
    450. 

  450. <code>NIL</code>), the function is allowed to destructively modify
    451. 

  451. <code><i>parse-tree</i></code> while creating the scanner.
    452. 

  452. <p>
    453. 

  453. If you want to find out how parse trees are related to Perl regex
    454. 

  454. strings, you should play around with
    455. 

  455. <a href="#parse-string"><code>PARSE-STRING</code></a>:
    456. 

  456. 

  457. <pre>
    458. 

  458. * (parse-string "(ab)*")
    459. 

  459. (:GREEDY-REPETITION 0 NIL (:REGISTER "ab"))
    460. 

  460. 

  461. * (parse-string "(a(b))")
    462. 

  462. (:REGISTER (:SEQUENCE #\a (:REGISTER #\b)))
    463. 

  463. 

  464. * (parse-string "(?:abc){3,5}")
    465. 

  465. (:GREEDY-REPETITION 3 5 (:GROUP "abc"))
    466. 

  466. <font color=orange>;; (:GREEDY-REPETITION 3 5 "abc") would also be OK</font>
    467. 

  467. 

  468. * (parse-string "a(?i)b(?-i)c")
    469. 

  469. (:SEQUENCE #\a
    470. 

  470.  (:SEQUENCE (:FLAGS :CASE-INSENSITIVE-P)
    471. 

  471.   (:SEQUENCE #\b (:SEQUENCE (:FLAGS :CASE-SENSITIVE-P) #\c))))
    472. 

  472. <font color=orange>;; same as (:SEQUENCE #\a :CASE-INSENSITIVE-P #\b :CASE-SENSITIVE-P #\c)</font>
    473. 

  473. 

  474. * (parse-string "(?=a)b")
    475. 

  475. (:SEQUENCE (:POSITIVE-LOOKAHEAD #\a) #\b)
    476. 

  476. </pre></blockquote>
    477. 

  477. 

  478. <p><br>
    479. 

  479. <font color=green><b>For the rest of the dictionary, </b><code><i>regex</i></code><b> can
    480. 

  480. always be a string (which is interpreted as a Perl regular
    481. 

  481. expression), a parse tree, or a scanner created by
    482. 

  482. <a href="#create-scanner"><font color=green><code>CREATE-SCANNER</code></font></a>.  The
    483. 

  483. </b><code><i>start</i></code><b> and </b><code><i>end</i></code><b>
    484. 

  484. keyword parameters are always used as in <a
    485. 

  485. href="#scan"><font color=green><code>SCAN</code></font></a>.</b></font>
    486. 

  486. 

  487. 

  488. 

  489. 

  490. <p><br>[Generic Function]
    491. 

  491. <br><a class=none name="scan"><b>scan</b> <i>regex target-string <tt>&amp;key</tt> start end</i> =&gt; <i>match-start, match-end, reg-starts, reg-ends</i></a>
    492. 

  492. 

  493. <blockquote><br>
    494. 

  494. Searches the string <code><i>target-string</i></code>
    495. 

  495. from <code><i>start</i></code> (which defaults to 0) to
    496. 

  496. <code><i>end</i></code> (which default to the length of
    497. 

  497. <code><i>target-string</i></code>) and tries to match
    498. 

  498. <code><i>regex</i></code>. On success returns four values - the start
    499. 

  499. of the match, the end of the match, and two arrays denoting the
    500. 

  500. beginnings and ends of register matches. On failure returns
    501. 

  501. <code>NIL</code>.  <code><i>target-string</i></code> will be coerced
    502. 

  502. to a simple string if it isn't one already. (There's another keyword
    503. 

  503. parameter <code><i>real-start-pos</i></code>.  This one should
    504. 

  504. <em>never</em> be set from user code - it is only used internally.)
    505. 

  505. <p>
    506. 

  506. <code>SCAN</code> acts as if the part of
    507. 

  507. <code><i>target-string</i></code> between <code><i>start</i></code>
    508. 

  508. and <code><i>end</i></code> were a standalone string, i.e. look-aheads
    509. 

  509. and look-behinds can't look beyond these boundaries.
    510. 

  510. <pre>
    511. 

  511. * (scan "(a)*b" "xaaabd")
    512. 

  512. 1
    513. 

  513. 5
    514. 

  514. #(3)
    515. 

  515. #(4)
    516. 

  516. 

  517. * (scan "(a)*b" "xaaabd" :start 1)
    518. 

  518. 1
    519. 

  519. 5
    520. 

  520. #(3)
    521. 

  521. #(4)
    522. 

  522. 

  523. * (scan "(a)*b" "xaaabd" :start 2)
    524. 

  524. 2
    525. 

  525. 5
    526. 

  526. #(3)
    527. 

  527. #(4)
    528. 

  528. 

  529. * (scan "(a)*b" "xaaabd" :end 4)
    530. 

  530. NIL
    531. 

  531. 

  532. * (scan '(:greedy-repetition 0 nil #\b) "bbbc")
    533. 

  533. 0
    534. 

  534. 3
    535. 

  535. #()
    536. 

  536. #()
    537. 

  537. 

  538. * (scan '(:greedy-repetition 4 6 #\b) "bbbc")
    539. 

  539. NIL
    540. 

  540. 

  541. * (let ((s (create-scanner "(([a-c])+)x")))
    542. 

  542.     (scan s "abcxy"))
    543. 

  543. 0
    544. 

  544. 4
    545. 

  545. #(0 2)
    546. 

  546. #(3 3)
    547. 

  547. </pre></blockquote>
    548. 

  548. 

  549. 

  550. 

  551. <p><br>[Function]
    552. 

  552. <br><a class=none name="scan-to-strings"><b>scan-to-strings</b> <i>regex target-string <tt>&amp;key</tt> start end sharedp</i> =&gt; <i>match, regs</i></a>
    553. 

  553. 

  554. <blockquote><br>
    555. 

  555. Like <a href="#scan"><code>SCAN</code></a> but returns substrings of
    556. 

  556. <code><i>target-string</i></code> instead of positions, i.e. this
    557. 

  557. function returns two values on success: the whole match as a string
    558. 

  558. plus an array of substrings (or <code>NIL</code>s) corresponding to
    559. 

  559. the matched registers. If <code><i>sharedp</i></code> is true, the substrings may share structure with
    560. 

  560. <code><i>target-string</i></code>.
    561. 

  561. <pre>
    562. 

  562. * (scan-to-strings "[^b]*b" "aaabd")
    563. 

  563. "aaab"
    564. 

  564. #()
    565. 

  565. 

  566. * (scan-to-strings "([^b])*b" "aaabd")
    567. 

  567. "aaab"
    568. 

  568. #("a")
    569. 

  569. 

  570. * (scan-to-strings "(([^b])*)b" "aaabd")
    571. 

  571. "aaab"
    572. 

  572. #("aaa" "a")
    573. 

  573. </pre></blockquote>
    574. 

  574. 

  575. 

  576. <p><br>[Macro]
    577. 

  577. <br><a class=none name="register-groups-bind"><b>register-groups-bind</b> <i>var-list (regex target-string <tt>&amp;key</tt> start end sharedp) declaration* statement*</i> =&gt; <i>result*</i></a>
    578. 

  578. 

  579. <blockquote><br>
    580. 

  580. Evaluates <code><i>statement*</i></code> with the variables in <code><i>var-list</i></code> bound to the
    581. 

  581. corresponding register groups after <code><i>target-string</i></code> has been matched
    582. 

  582. against <code><i>regex</i></code>, i.e. each variable is either
    583. 

  583. bound to a string or to <code>NIL</code>.
    584. 

  584. As a shortcut, the elements of <code><i>var-list</i></code> can also be lists of the form <code>(FN&nbsp;VAR)</code> where <code>VAR</code> is the variable symbol
    585. 

  585. and <code>FN</code> is a <a
    586. 

  586. href="http://www.lispworks.com/documentation/HyperSpec/Body/26_glo_f.htm#function_designator">function
    587. 

  587. designator</a> (which is evaluated) denoting a function which is to be applied to the string before the result is bound to <code>VAR</code>.
    588. 

  588. To make this even more convenient the form <code>(FN&nbsp;VAR1&nbsp;...VARn)</code> can be used as an abbreviation for
    589. 

  589. <code>(FN&nbsp;VAR1)&nbsp;...&nbsp;(FN&nbsp;VARn)</code>.
    590. 

  590. <p>
    591. 

  591. If there is no match, the <code><i>statement*</i></code> forms are <em>not</em>
    592. 

  592. executed. For each element of
    593. 

  593. <code><i>var-list</i></code> which is <code>NIL</code> there's no binding to the corresponding register
    594. 

  594. group. The number of variables in <code><i>var-list</i></code> must not be greater than
    595. 

  595. the number of register groups. If <code><i>sharedp</i></code> is true, the substrings may
    596. 

  596. share structure with <code><i>target-string</i></code>.
    597. 

  597. <pre>
    598. 

  598. * (register-groups-bind (first second third fourth)
    599. 

  599.       (&quot;((a)|(b)|(c))+&quot; &quot;abababc&quot; :sharedp t)
    600. 

  600.     (list first second third fourth))
    601. 

  601. (&quot;c&quot; &quot;a&quot; &quot;b&quot; &quot;c&quot;)
    602. 

  602. 

  603. * (register-groups-bind (nil second third fourth)
    604. 

  604.       <font color=orange>;; note that we don't bind the first and fifth register group</font>
    605. 

  605.       (&quot;((a)|(b)|(c))()+&quot; &quot;abababc&quot; :start 6)
    606. 

  606.     (list second third fourth))
    607. 

  607. (NIL NIL &quot;c&quot;)
    608. 

  608. 

  609. * (register-groups-bind (first)
    610. 

  610.       (&quot;(a|b)+&quot; &quot;accc&quot; :start 1)
    611. 

  611.     (format t &quot;This will not be printed: ~A&quot; first))
    612. 

  612. NIL
    613. 

  613. 

  614. * (register-groups-bind (fname lname (#'parse-integer date month year))
    615. 

  615.       (&quot;(\\w+)\\s+(\\w+)\\s+(\\d{1,2})\\.(\\d{1,2})\\.(\\d{4})&quot; &quot;Frank Zappa 21.12.1940&quot;)
    616. 

  616.     (list fname lname (encode-universal-time 0 0 0 date month year 0)))
    617. 

  617. ("Frank" "Zappa" 1292889600)
    618. 

  618. </pre>
    619. 

  619. </blockquote>
    620. 

  620. 

  621. <p><br>[Macro]
    622. 

  622. <br><a class=none name="do-scans"><b>do-scans</b> <i>(match-start match-end reg-starts reg-ends regex target-string <tt>&amp;optional</tt> result-form <tt>&amp;key</tt> start end) declaration* statement*</i> =&gt; <i>result*</i></a>
    623. 

  623. 

  624. <blockquote><br>
    625. 

  625. A macro which iterates over <code><i>target-string</i></code> and
    626. 

  626. tries to match <code><i>regex</i></code> as often as possible
    627. 

  627. evaluating <code><i>statement*</i></code> with
    628. 

  628. <code><i>match-start</i></code>, <code><i>match-end</i></code>,
    629. 

  629. <code><i>reg-starts</i></code>, and <code><i>reg-ends</i></code> bound
    630. 

  630. to the four return values of each match (see <a
    631. 

  631. href="#scan"><code>SCAN</code></a>) in turn. After the last match,
    632. 

  632. returns <code><i>result-form</i></code> if provided or
    633. 

  633. <code>NIL</code> otherwise. An implicit block named <code>NIL</code>
    634. 

  634. surrounds <code>DO-SCANS</code>; <code>RETURN</code> may be used to
    635. 

  635. terminate the loop immediately. If <code><i>regex</i></code> matches
    636. 

  636. an empty string, the scan is continued one position behind this match.
    637. 

  637. <p>
    638. 

  638. This is the most general macro to iterate over all matches in a target
    639. 

  639. string. See the source code of <a
    640. 

  640. href="#do-matches"><code>DO-MATCHES</code></a>, <a
    641. 

  641. href="#all-matches"><code>ALL-MATCHES</code></a>, <a
    642. 

  642. href="#split"><code>SPLIT</code></a>, or <a
    643. 

  643. href="#regex-replace-all"><code>REGEX-REPLACE-ALL</code></a> for examples of its
    644. 

  644. usage.</blockquote>
    645. 

  645. 

  646. 

  647. 

  648. 

  649. <p><br>[Macro]
    650. 

  650. <br><a class=none name="do-matches"><b>do-matches</b> <i>(match-start match-end regex target-string <tt>&amp;optional</tt> result-form <tt>&amp;key</tt> start end) declaration* statement*</i> =&gt; <i>result*</i></a>
    651. 

  651. 

  652. <blockquote><br>
    653. 

  653. Like <a href="#do-scans"><code>DO-SCANS</code></a> but doesn't bind
    654. 

  654. variables to the register arrays.
    655. 

  655. <pre>
    656. 

  656. * (defun foo (regex target-string &amp;key (start 0) (end (length target-string)))
    657. 

  657.     (let ((sum 0))
    658. 

  658.       (do-matches (s e regex target-string nil :start start :end end)
    659. 

  659.         (incf sum (- e s)))
    660. 

  660.       (format t "~,2F% of the string was inside of a match~%"
    661. 

  661.                 <font color=orange>;; note: doesn't check for division by zero</font>
    662. 

  662.                 (float (* 100 (/ sum (- end start)))))))
    663. 

  663. 

  664. FOO
    665. 

  665. 

  666. * (foo "a" "abcabcabc")
    667. 

  667. 33.33% of the string was inside of a match
    668. 

  668. NIL
    669. 

  669. * (foo "aa|b" "aacabcbbc")
    670. 

  670. 55.56% of the string was inside of a match
    671. 

  671. NIL
    672. 

  672. </pre></blockquote>
    673. 

  673. 

  674. 

  675. 

  676. 

  677. <p><br>[Macro]
    678. 

  678. <br><a class=none name="do-matches-as-strings"><b>do-matches-as-strings</b> <i>(match-var regex target-string <tt>&amp;optional</tt> result-form <tt>&amp;key</tt> start end sharedp) declaration* statement*</i> =&gt; <i>result*</i></a>
    679. 

  679. 

  680. <blockquote><br>
    681. 

  681. Like <a href="#do-matches"><code>DO-MATCHES</code></a> but binds
    682. 

  682. <code><i>match-var</i></code> to the substring of
    683. 

  683. <code><i>target-string</i></code> corresponding to each match in turn. If <code><i>sharedp</i></code> is true, the substrings may share structure with
    684. 

  684. <code><i>target-string</i></code>.
    685. 

  685. <pre>
    686. 

  686. * (defun crossfoot (target-string &amp;key (start 0) (end (length target-string)))
    687. 

  687.     (let ((sum 0))
    688. 

  688.       (do-matches-as-strings (m :digit-class
    689. 

  689.                                          target-string nil
    690. 

  690.                                          :start start :end end)
    691. 

  691.         (incf sum (parse-integer m)))
    692. 

  692.       (if (< sum 10)
    693. 

  693.         sum
    694. 

  694.         (crossfoot (format nil "~A" sum)))))
    695. 

  695. 

  696. CROSSFOOT
    697. 

  697. 

  698. * (crossfoot "bar")
    699. 

  699. 0
    700. 

  700. 

  701. * (crossfoot "a3x")
    702. 

  702. 3
    703. 

  703. 

  704. * (crossfoot "12345")
    705. 

  705. 6
    706. 

  706. </pre>
    707. 

  707. 

  708. Of course, in real life you would do this with <a href="#do-matches"><code>DO-MATCHES</code></a> and use the <code><i>start</i></code> and <code><i>end</i></code> keyword parameters of <a href="http://www.lispworks.com/documentation/HyperSpec/Body/f_parse_.htm"><code>PARSE-INTEGER</code></a>.</blockquote>
    709. 

  709. 

  710. <p><br>[Macro]
    711. 

  711. <br><a class=none name="do-register-groups"><b>do-register-groups</b> <i>var-list (regex target-string <tt>&amp;optional</tt> result-form <tt>&amp;key</tt> start end sharedp) declaration* statement*</i> =&gt; <i>result*</i></a>
    712. 

  712. 

  713. <blockquote><br>
    714. 

  714. Iterates over <code><i>target-string</i></code> and tries to match <code><i>regex</i></code> as often as
    715. 

  715. possible evaluating <code><i>statement*</i></code> with the variables in <code><i>var-list</i></code> bound to the
    716. 

  716. corresponding register groups for each match in turn, i.e. each
    717. 

  717. variable is either bound to a string or to <code>NIL</code>. You can use the same shortcuts and abbreviations as in <a href="#register-groups-bind"><code>REGISTER-GROUPS-BIND</code></a>. The number of
    718. 

  718. variables in <code><i>var-list</i></code> must not be greater than the number of register
    719. 

  719. groups. For each element of
    720. 

  720. <code><i>var-list</i></code> which is <code>NIL</code> there's no binding to the corresponding register
    721. 

  721. group. After the last match, returns <code><i>result-form</i></code> if provided or <code>NIL</code>
    722. 

  722. otherwise. An implicit block named <code>NIL</code> surrounds <code>DO-REGISTER-GROUPS</code>;
    723. 

  723. <code>RETURN</code> may be used to terminate the loop immediately. If <code><i>regex</i></code> matches
    724. 

  724. an empty string, the scan is continued one position behind this
    725. 

  725. match. If <code><i>sharedp</i></code> is true, the substrings may share structure with
    726. 

  726. <code><i>target-string</i></code>.
    727. 

  727. <pre>
    728. 

  728. * (do-register-groups (first second third fourth)
    729. 

  729.       (&quot;((a)|(b)|(c))&quot; &quot;abababc&quot; nil :start 2 :sharedp t)
    730. 

  730.     (print (list first second third fourth)))
    731. 

  731. (&quot;a&quot; &quot;a&quot; NIL NIL) 
    732. 

  732. (&quot;b&quot; NIL &quot;b&quot; NIL) 
    733. 

  733. (&quot;a&quot; &quot;a&quot; NIL NIL) 
    734. 

  734. (&quot;b&quot; NIL &quot;b&quot; NIL) 
    735. 

  735. (&quot;c&quot; NIL NIL &quot;c&quot;)
    736. 

  736. NIL
    737. 

  737. 

  738. * (let (result)
    739. 

  739.     (do-register-groups ((#'parse-integer n) (#'intern sign) whitespace)
    740. 

  740.         (&quot;(\\d+)|(\\+|-|\\*|/)|(\\s+)&quot; &quot;12*15 - 42/3&quot;)
    741. 

  741.       (unless whitespace
    742. 

  742.         (push (or n sign) result)))
    743. 

  743.     (nreverse result))
    744. 

  744. (12 * 15 - 42 / 3)
    745. 

  745. </pre>
    746. 

  746. </blockquote>
    747. 

  747. 

  748. 

  749. <p><br>[Function]
    750. 

  750. <br><a class=none name="all-matches"><b>all-matches</b> <i>regex target-string <tt>&amp;key</tt> start end</i> =&gt; <i>list</i></a>
    751. 

  751. 

  752. <blockquote><br>
    753. 

  753. Returns a list containing the start and end positions of all matches
    754. 

  754. of <code><i>regex</i></code> against
    755. 

  755. <code><i>target-string</i></code>, i.e. if there are <code>N</code>
    756. 

  756. matches the list contains <code>(* 2 N)</code> elements. If
    757. 

  757. <code><i>regex</i></code> matches an empty string the scan is
    758. 

  758. continued one position behind this match.
    759. 

  759. <pre>
    760. 

  760. * (all-matches "a" "foo bar baz")
    761. 

  761. (5 6 9 10)
    762. 

  762. 

  763. * (all-matches "\\w*" "foo bar baz")
    764. 

  764. (0 3 3 3 4 7 7 7 8 11 11 11)
    765. 

  765. </pre></blockquote>
    766. 

  766. 

  767. 

  768. 

  769. 

  770. <p><br>[Function]
    771. 

  771. <br><a class=none name="all-matches-as-strings"><b>all-matches-as-strings</b> <i>regex target-string <tt>&amp;key</tt> start end sharedp</i> =&gt; <i>list</i></a>
    772. 

  772. 

  773. <blockquote><br>
    774. 

  774. Like <a href="#all-matches"><code>ALL-MATCHES</code></a> but
    775. 

  775. returns a list of substrings instead. If <code><i>sharedp</i></code> is true, the substrings may share structure with
    776. 

  776. <code><i>target-string</i></code>.
    777. 

  777. <pre>
    778. 

  778. * (all-matches-as-strings "a" "foo bar baz")
    779. 

  779. ("a" "a")
    780. 

  780. 

  781. * (all-matches-as-strings "\\w*" "foo bar baz")
    782. 

  782. ("foo" "" "bar" "" "baz" "")
    783. 

  783. </pre></blockquote>
    784. 

  784. 

  785. 

  786. 

  787. 

  788. <h4><a name="splitting" class=none>Splitting and replacing</a></h4>
    789. 

  789. 

  790. 

  791. <p><br>[Function]
    792. 

  792. <br><a class=none name="split"><b>split</b> <i>regex target-string <tt>&amp;key</tt> start end limit with-registers-p omit-unmatched-p sharedp</i> =&gt; <i>list</i></a>
    793. 

  793. 

  794. <blockquote><br>
    795. 

  795. Matches <code><i>regex</i></code> against
    796. 

  796. <code><i>target-string</i></code> as often as possible and returns a
    797. 

  797. list of the substrings between the matches. If
    798. 

  798. <code><i>with-registers-p</i></code> is true, substrings corresponding
    799. 

  799. to matched registers are inserted into the list as well.  If
    800. 

  800. <code><i>omit-unmatched-p</i></code> is true, unmatched registers will
    801. 

  801. simply be left out, otherwise they will show up as
    802. 

  802. <code>NIL</code>. <code><i>limit</i></code> limits the number of
    803. 

  803. elements returned - registers aren't counted. If
    804. 

  804. <code><i>limit</i></code> is <code>NIL</code> (or 0 which is
    805. 

  805. equivalent), trailing empty strings are removed from the result list.
    806. 

  806. If <code><i>regex</i></code> matches an empty string, the scan is
    807. 

  807. continued one position behind this match. If <code><i>sharedp</i></code> is true, the substrings may share structure with
    808. 

  808. <code><i>target-string</i></code>.
    809. 

  809. <p>
    810. 

  810. This function also tries hard to be
    811. 

  811. Perl-compatible - thus the somewhat peculiar behaviour.
    812. 

  812. <pre>
    813. 

  813. * (split "\\s+" "foo   bar baz
    814. 

  814. frob")
    815. 

  815. ("foo" "bar" "baz" "frob")
    816. 

  816. 

  817. * (split "\\s*" "foo bar   baz")
    818. 

  818. ("f" "o" "o" "b" "a" "r" "b" "a" "z")
    819. 

  819. 

  820. * (split "(\\s+)" "foo bar   baz")
    821. 

  821. ("foo" "bar" "baz")
    822. 

  822. 

  823. * (split "(\\s+)" "foo bar   baz" :with-registers-p t)
    824. 

  824. ("foo" " " "bar" "   " "baz")
    825. 

  825. 

  826. * (split "(\\s)(\\s*)" "foo bar   baz" :with-registers-p t)
    827. 

  827. ("foo" " " "" "bar" " " "  " "baz")
    828. 

  828. 

  829. * (split "(,)|(;)" "foo,bar;baz" :with-registers-p t)
    830. 

  830. ("foo" "," NIL "bar" NIL ";" "baz")
    831. 

  831. 

  832. * (split "(,)|(;)" "foo,bar;baz" :with-registers-p t :omit-unmatched-p t)
    833. 

  833. ("foo" "," "bar" ";" "baz")
    834. 

  834. 

  835. * (split ":" "a:b:c:d:e:f:g::")
    836. 

  836. ("a" "b" "c" "d" "e" "f" "g")
    837. 

  837. 

  838. * (split ":" "a:b:c:d:e:f:g::" :limit 1)
    839. 

  839. ("a:b:c:d:e:f:g::")
    840. 

  840. 

  841. * (split ":" "a:b:c:d:e:f:g::" :limit 2)
    842. 

  842. ("a" "b:c:d:e:f:g::")
    843. 

  843. 

  844. * (split ":" "a:b:c:d:e:f:g::" :limit 3)
    845. 

  845. ("a" "b" "c:d:e:f:g::")
    846. 

  846. 

  847. * (split ":" "a:b:c:d:e:f:g::" :limit 1000)
    848. 

  848. ("a" "b" "c" "d" "e" "f" "g" "" "")
    849. 

  849. </pre></blockquote>
    850. 

  850. 

  851. 

  852. 

  853. 

  854. 

  855. <p><br>[Function]
    856. 

  856. <br><a class=none name="regex-replace"><b>regex-replace</b> <i>regex target-string replacement <tt>&amp;key</tt> start end preserve-case simple-calls element-type</i> =&gt; <i>string, matchp</i></a>
    857. 

  857. 

  858. <blockquote><br> Try to match <code><i>target-string</i></code>
    859. 

  859. between <code><i>start</i></code> and <code><i>end</i></code> against
    860. 

  860. <code><i>regex</i></code> and replace the first match with
    861. 

  861. <code><i>replacement</i></code>. Two values are returned; the modified
    862. 

  862. string, and <code>T</code> if <code><i>regex</i></code> matched or
    863. 

  863. <code>NIL</code> otherwise.
    864. 

  864. <p>
    865. 

  865. <code><i>replacement</i></code> can be a string which may contain the
    866. 

  866. special substrings <code>&quot;\&amp;&quot;</code> for the whole
    867. 

  867. match, <code>&quot;\`&quot;</code> for the part of
    868. 

  868. <code><i>target-string</i></code> before the match,
    869. 

  869. <code>&quot;\'&quot;</code> for the part of
    870. 

  870. <code><i>target-string</i></code> after the match,
    871. 

  871. <code>&quot;\N&quot;</code> or <code>&quot;\{N}&quot;</code> for the
    872. 

  872. <code>N</code>th register where <code>N</code> is a positive integer.
    873. 

  873. <p>
    874. 

  874. <code><i>replacement</i></code> can also be a <a
    875. 

  875. href="http://www.lispworks.com/documentation/HyperSpec/Body/26_glo_f.htm#function_designator">function
    876. 

  876. designator</a> in which case the match will be replaced with the
    877. 

  877. result of calling the function designated by
    878. 

  878. <code><i>replacement</i></code> with the arguments
    879. 

  879. <code><i>target-string</i></code>, <code><i>start</i></code>,
    880. 

  880. <code><i>end</i></code>, <code><i>match-start</i></code>,
    881. 

  881. <code><i>match-end</i></code>, <code><i>reg-starts</i></code>, and
    882. 

  882. <code><i>reg-ends</i></code>. (<code><i>reg-starts</i></code> and
    883. 

  883. <code><i>reg-ends</i></code> are arrays holding the start and end
    884. 

  884. positions of matched registers (or <code>NIL</code>) - the meaning of
    885. 

  885. the other arguments should be obvious.)
    886. 

  886. <p>
    887. 

  887. If <code><i>simple-calls</i></code> is true, a function designated by
    888. 

  888. <code><i>replacement</i></code> will instead be called with the
    889. 

  889. arguments <code><i>match</i></code>, <code><i>register-1</i></code>,
    890. 

  890. ..., <code><i>register-n</i></code> where <code><i>match</i></code> is
    891. 

  891. the whole match as a string and <code><i>register-1</i></code> to
    892. 

  892. <code><i>register-n</i></code> are the matched registers, also as
    893. 

  893. strings (or <code>NIL</code>). Note that these strings share structure with
    894. 

  894. <code><i>target-string</i></code> so you must not modify them.
    895. 

  895. <p>
    896. 

  896. Finally, <code><i>replacement</i></code> can be a list where each
    897. 

  897. element is a string (which will be inserted verbatim), one of the
    898. 

  898. symbols <code>:match</code>, <code>:before-match</code>, or
    899. 

  899. <code>:after-match</code> (corresponding to
    900. 

  900. <code>&quot;\&amp;&quot;</code>, <code>&quot;\`&quot;</code>, and
    901. 

  901. <code>&quot;\'&quot;</code> above), an integer <code>N</code>
    902. 

  902. (representing register <code>(1+&nbsp;N)</code>), or a function
    903. 

  903. designator.
    904. 

  904. <p>
    905. 

  905. If <code><i>preserve-case</i></code> is true (default is
    906. 

  906. <code>NIL</code>), the replacement will try to preserve the case (all
    907. 

  907. upper case, all lower case, or capitalized) of the match. The result
    908. 

  908. will always be a <a
    909. 

  909. href="http://www.lispworks.com/documentation/HyperSpec/Body/26_glo_f.htm#fresh">fresh</a>
    910. 

  910. string, even if <code><i>regex</i></code> doesn't match.
    911. 

  911. <p>
    912. 

  912. <code><i>element-type</i></code> specifies
    913. 

  913. the <a
    914. 

  914. href="http://www.lispworks.com/documentation/HyperSpec/Body/26_glo_a.htm#array_element_type">array
    915. 

  915. element type</a> of the string which is returned, the default
    916. 

  916. is <a
    917. 

  917. href="http://www.lispworks.com/documentation/lw50/LWRM/html/lwref-346.htm"><code>LW:SIMPLE-CHAR</code></a>
    918. 

  918. for LispWorks
    919. 

  919. and <a
    920. 

  920. href="http://www.lispworks.com/documentation/HyperSpec/Body/t_ch.htm"><code>CHARACTER</code></a>
    921. 

  921. for other Lisps.
    922. 

  922. <pre>
    923. 

  923. * (regex-replace "fo+" "foo bar" "frob")
    924. 

  924. "frob bar"
    925. 

  925. T
    926. 

  926. 

  927. * (regex-replace "fo+" "FOO bar" "frob")
    928. 

  928. "FOO bar"
    929. 

  929. NIL
    930. 

  930. 

  931. * (regex-replace "(?i)fo+" "FOO bar" "frob")
    932. 

  932. "frob bar"
    933. 

  933. T
    934. 

  934. 

  935. * (regex-replace "(?i)fo+" "FOO bar" "frob" :preserve-case t)
    936. 

  936. "FROB bar"
    937. 

  937. T
    938. 

  938. 

  939. * (regex-replace "(?i)fo+" "Foo bar" "frob" :preserve-case t)
    940. 

  940. "Frob bar"
    941. 

  941. T
    942. 

  942. 

  943. * (regex-replace "bar" "foo bar baz" "[frob (was '\\&' between '\\`' and '\\'')]")
    944. 

  944. "foo [frob (was 'bar' between 'foo ' and ' baz')] baz"
    945. 

  945. T
    946. 

  946. 

  947. * (regex-replace "bar" "foo bar baz"
    948. 

  948.                           '("[frob (was '" :match "' between '" :before-match "' and '" :after-match "')]"))
    949. 

  949. "foo [frob (was 'bar' between 'foo ' and ' baz')] baz"
    950. 

  950. T
    951. 

  951. 

  952. * (regex-replace "(be)(nev)(o)(lent)"
    953. 

  953.                           "benevolent: adj. generous, kind"
    954. 

  954.                           #'(lambda (match &amp;rest registers)
    955. 

  955.                               (format nil "~A [~{~A~^.~}]" match registers))
    956. 

  956.                           :simple-calls t)
    957. 

  957. "benevolent [be.nev.o.lent]: adj. generous, kind"
    958. 

  958. T
    959. 

  959. </pre></blockquote>
    960. 

  960. 

  961. 

  962. <p><br>[Function]
    963. 

  963. <br><a class=none name="regex-replace-all"><b>regex-replace-all</b> <i>regex target-string replacement <tt>&amp;key</tt> start end preserve-case simple-calls element-type</i> =&gt; <i>string, matchp</i></a>
    964. 

  964. 

  965. <blockquote><br>
    966. 

  966. Like <a href="#regex-replace"><code>REGEX-REPLACE</code></a> but replaces all matches.
    967. 

  967. <pre>
    968. 

  968. * (regex-replace-all "(?i)fo+" "foo Fooo FOOOO bar" "frob" :preserve-case t)
    969. 

  969. "frob Frob FROB bar"
    970. 

  970. T
    971. 

  971. 

  972. * (regex-replace-all "(?i)f(o+)" "foo Fooo FOOOO bar" "fr\\1b" :preserve-case t)
    973. 

  973. "froob Frooob FROOOOB bar"
    974. 

  974. T
    975. 

  975. 

  976. * (let ((qp-regex (create-scanner "[\\x80-\\xff]")))
    977. 

  977.     (defun encode-quoted-printable (string)
    978. 

  978.       "Converts 8-bit string to quoted-printable representation."
    979. 

  979.       <font color=orange>;; won't work for Corman Lisp because non-ASCII characters aren't 8-bit there</font>
    980. 

  980.       (flet ((convert (target-string start end match-start match-end reg-starts reg-ends)
    981. 

  981.              (declare (ignore start end match-end reg-starts reg-ends))
    982. 

  982.              (format nil "=~2,'0x" (char-code (char target-string match-start)))))
    983. 

  983.         (regex-replace-all qp-regex string #'convert))))
    984. 

  984. Converted ENCODE-QUOTED-PRINTABLE.
    985. 

  985. ENCODE-QUOTED-PRINTABLE
    986. 

  986. 

  987. * (encode-quoted-printable "F&ecirc;te S&oslash;rensen na&iuml;ve H&uuml;hner Stra&szlig;e")
    988. 

  988. "F=EAte S=F8rensen na=EFve H=FChner Stra=DFe"
    989. 

  989. T
    990. 

  990. 

  991. * (let ((url-regex (create-scanner "[^a-zA-Z0-9_\\-.]")))
    992. 

  992.     (defun url-encode (string)
    993. 

  993.       "URL-encodes a string."
    994. 

  994.       <font color=orange>;; won't work for Corman Lisp because non-ASCII characters aren't 8-bit there</font>
    995. 

  995.       (flet ((convert (target-string start end match-start match-end reg-starts reg-ends)
    996. 

  996.              (declare (ignore start end match-end reg-starts reg-ends))
    997. 

  997.              (format nil "%~2,'0x" (char-code (char target-string match-start)))))
    998. 

  998.         (regex-replace-all url-regex string #'convert))))
    999. 

  999. Converted URL-ENCODE.
    1000. 

  1000. URL-ENCODE
    1001. 

  1001. 

  1002. * (url-encode "F&ecirc;te S&oslash;rensen na&iuml;ve H&uuml;hner Stra&szlig;e")
    1003. 

  1003. "F%EAte%20S%F8rensen%20na%EFve%20H%FChner%20Stra%DFe"
    1004. 

  1004. T
    1005. 

  1005. 

  1006. * (defun how-many (target-string start end match-start match-end reg-starts reg-ends)
    1007. 

  1007.     (declare (ignore start end match-start match-end))
    1008. 

  1008.     (format nil "~A" (- (svref reg-ends 0)
    1009. 

  1009.                         (svref reg-starts 0))))
    1010. 

  1010. HOW-MANY
    1011. 

  1011. 

  1012. * (regex-replace-all "{(.+?)}"
    1013. 

  1013.                               "foo{...}bar{.....}{..}baz{....}frob"
    1014. 

  1014.                               (list "[" 'how-many " dots]"))
    1015. 

  1015. "foo[3 dots]bar[5 dots][2 dots]baz[4 dots]frob"
    1016. 

  1016. T
    1017. 

  1017. 

  1018. * (let ((qp-regex (create-scanner "[\\x80-\\xff]")))
    1019. 

  1019.     (defun encode-quoted-printable (string)
    1020. 

  1020.       "Converts 8-bit string to quoted-printable representation.
    1021. 

  1021. Version using SIMPLE-CALLS keyword argument."
    1022. 

  1022.       <font color=orange>;; ;; won't work for Corman Lisp because non-ASCII characters aren't 8-bit there</font>
    1023. 

  1023.       (flet ((convert (match)
    1024. 

  1024.                (format nil "=~2,'0x" (char-code (char match 0)))))
    1025. 

  1025.         (regex-replace-all qp-regex string #'convert
    1026. 

  1026.                                     :simple-calls t))))
    1027. 

  1027. 

  1028. Converted ENCODE-QUOTED-PRINTABLE.
    1029. 

  1029. ENCODE-QUOTED-PRINTABLE
    1030. 

  1030. 

  1031. * (encode-quoted-printable "F&ecirc;te S&oslash;rensen na&iuml;ve H&uuml;hner Stra&szlig;e")
    1032. 

  1032. "F=EAte S=F8rensen na=EFve H=FChner Stra=DFe"
    1033. 

  1033. T
    1034. 

  1034. 

  1035. * (defun how-many (match first-register)
    1036. 

  1036.     (declare (ignore match))
    1037. 

  1037.     (format nil "~A" (length first-register)))
    1038. 

  1038. HOW-MANY
    1039. 

  1039. 

  1040. * (regex-replace-all "{(.+?)}"
    1041. 

  1041.                               "foo{...}bar{.....}{..}baz{....}frob"
    1042. 

  1042.                               (list "[" 'how-many " dots]")
    1043. 

  1043.                               :simple-calls t)
    1044. 

  1044. 

  1045. "foo[3 dots]bar[5 dots][2 dots]baz[4 dots]frob"
    1046. 

  1046. T
    1047. 

  1047. </pre></blockquote>
    1048. 

  1048. 

  1049. <h4><a name="modify" class=none>Modifying scanner behaviour</a></h4>
    1050. 

  1050. 

  1051. <p><br>[Special variable]
    1052. 

  1052. <br><a class=none name="*property-resolver*"><b>*property-resolver*</b></a>
    1053. 

  1053. 

  1054. </p><blockquote><br> This is the designator for a function responsible
    1055. 

  1055. for resolving named properties like <code>\p{Number}</code>.  If
    1056. 

  1056. CL-PPCRE encounters a <code>\p</code> or a <code>\P</code> it expects
    1057. 

  1057. to see an opening curly brace immediately afterwards and will then
    1058. 

  1058. read everything following that brace until it sees a closing curly
    1059. 

  1059. brace.  The resolver function will be called with this string and must
    1060. 

  1060. return a corresponding unary test function which accepts a character
    1061. 

  1061. as its argument and returns a true value if and only if the character
    1062. 

  1062. has the named property.  If the resolver returns <code>NIL</code>
    1063. 

  1063. instead, it signals that a property of that name is unknown.
    1064. 

  1064. <pre>
    1065. 

  1065. * (labels ((char-code-odd-p (char)
    1066. 

  1066.              (oddp (char-code char)))
    1067. 

  1067.            (char-code-even-p (char)
    1068. 

  1068.              (evenp (char-code char)))
    1069. 

  1069.            (resolver (name)
    1070. 

  1070.              (cond ((string= name "odd") #'char-code-odd-p)
    1071. 

  1071.                    ((string= name "even") #'char-code-even-p)
    1072. 

  1072.                    ((string= name "true") (constantly t))
    1073. 

  1073.                    (t (error "Can't resolve ~S." name)))))
    1074. 

  1074.     (let ((*property-resolver* #'resolver))
    1075. 

  1075.       <font color=orange>;; quiz question - why do we need CREATE-SCANNER here?</font>
    1076. 

  1076.       (list (regex-replace-all (create-scanner "\\p{odd}") "abcd" "+")
    1077. 

  1077.             (regex-replace-all (create-scanner "\\p{even}") "abcd" "+")
    1078. 

  1078.             (regex-replace-all (create-scanner "\\p{true}") "abcd" "+"))))
    1079. 

  1079. ("+b+d" "a+c+" "++++")
    1080. 

  1080. </pre>
    1081. 

  1081. If the value
    1082. 

  1082. of <a href="#*property-resolver*"><code>*PROPERTY-RESOLVER*</code></a>
    1083. 

  1083. is <code>NIL</code> (which is the default), <code>\p</code> and <code>\P</code> in regex
    1084. 

  1084. strings will simply be treated like <code>p</code> or <code>P</code>
    1085. 

  1085. as in CL-PPCRE&nbsp;1.4.1 and earlier.  Note that this does not affect
    1086. 

  1086. the validity of <code>(:PROPERTY&nbsp;&lt;<i>name</i>&gt;)</code>
    1087. 

  1087. parts in <a href="#create-scanner2">S-expression syntax</a>.
    1088. 

  1088. </blockquote>
    1089. 

  1089. 

  1090. 

  1091. <p><br>[Accessor]
    1092. 

  1092. <br><a class="none" name="parse-tree-synonym"><b>parse-tree-synonym</b> <i>symbol</i> =&gt; <i>parse-tree</i>
    1093. 

  1093. <br><tt>(setf (</tt><b>parse-tree-synonym</b> <i>symbol</i><tt>)</tt> <i>new-parse-tree</i><tt>)</tt></a>
    1094. 

  1094. 

  1095. </p><blockquote><br>
    1096. 

  1096. Any symbol (unless it's a keyword with a special meaning in parse
    1097. 

  1097. trees) can be made a "synonym", i.e. an abbreviation, for another parse
    1098. 

  1098. tree by this accessor. <code>PARSE-TREE-SYNONYM</code> returns <code>NIL</code> if <code><i>symbol</i></code> isn't a synonym yet.
    1099. 

  1099. <pre>
    1100. 

  1100. * (parse-string "a*b+")
    1101. 

  1101. (:SEQUENCE (:GREEDY-REPETITION 0 NIL #\a) (:GREEDY-REPETITION 1 NIL #\b))
    1102. 

  1102. 

  1103. * (defun my-repetition (char min)
    1104. 

  1104.     `(:greedy-repetition ,min nil ,char))
    1105. 

  1105. MY-REPETITION
    1106. 

    1107. 

  1107. * (setf (parse-tree-synonym 'a*) (my-repetition #\a 0))
    1108. 

  1108. (:GREEDY-REPETITION 0 NIL #\a)
    1109. 

    1110. 

  1110. * (setf (parse-tree-synonym 'b+) (my-repetition #\b 1))
    1111. 

  1111. (:GREEDY-REPETITION 1 NIL #\b)
    1112. 

    1113. 

  1113. * (let ((scanner (create-scanner '(:sequence a* b+))))
    1114. 

  1114.     (dolist (string '("ab" "b" "aab" "a" "x"))
    1115. 

  1115.       (print (scan scanner string)))
    1116. 

  1116.     (values))
    1117. 

  1117. 0
    1118. 

  1118. 0
    1119. 

  1119. 0
    1120. 

  1120. NIL
    1121. 

  1121. NIL
    1122. 

    1123. 

  1123. * (parse-tree-synonym 'a*)
    1124. 

  1124. (:GREEDY-REPETITION 0 NIL #\a)
    1125. 

    1126. 

  1126. * (parse-tree-synonym 'a+)
    1127. 

  1127. NIL
    1128. 

  1128. </pre></blockquote>
    1129. 

    1130. 

  1130. <p><br>[Macro]
    1131. 

  1131. <br><a class="none" name="define-parse-tree-synonym"><b>define-parse-tree-synonym</b> <i>name parse-tree</i> =&gt; <i>parse-tree</i></a>
    1132. 

    1133. 

  1133. </p><blockquote><br>
    1134. 

  1134. This is a convenience macro for parse tree synonyms defined as
    1135. 

    1136. 

  1136. <pre>
    1137. 

  1137. (defmacro define-parse-tree-synonym (name parse-tree)
    1138. 

  1138.   `(eval-when (:compile-toplevel :load-toplevel :execute)
    1139. 

  1139.      (setf (parse-tree-synonym ',name) ',parse-tree)))
    1140. 

  1140. </pre>
    1141. 

  1141. 

  1142. so you can write code like this:
    1143. 

  1143. 

  1144. <pre>
    1145. 

  1145. (define-parse-tree-synonym a-z
    1146. 

  1146.   (:char-class (:range #\a #\z) (:range #\A #\Z)))
    1147. 

  1147. 

  1148. (define-parse-tree-synon…
    1149.

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