Annotation of embedaddon/php/ext/mbstring/oniguruma/doc/RE, revision 1.1.1.1
1.1 misho 1: Oniguruma Regular Expressions Version 4.3.0 2006/08/17
2:
3: syntax: ONIG_SYNTAX_RUBY (default)
4:
5:
6: 1. Syntax elements
7:
8: \ escape (enable or disable meta character meaning)
9: | alternation
10: (...) group
11: [...] character class
12:
13:
14: 2. Characters
15:
16: \t horizontal tab (0x09)
17: \v vertical tab (0x0B)
18: \n newline (0x0A)
19: \r return (0x0D)
20: \b back space (0x08)
21: \f form feed (0x0C)
22: \a bell (0x07)
23: \e escape (0x1B)
24: \nnn octal char (encoded byte value)
25: \xHH hexadecimal char (encoded byte value)
26: \x{7HHHHHHH} wide hexadecimal char (character code point value)
27: \cx control char (character code point value)
28: \C-x control char (character code point value)
29: \M-x meta (x|0x80) (character code point value)
30: \M-\C-x meta control char (character code point value)
31:
32: (* \b is effective in character class [...] only)
33:
34:
35: 3. Character types
36:
37: . any character (except newline)
38:
39: \w word character
40:
41: Not Unicode:
42: alphanumeric, "_" and multibyte char.
43:
44: Unicode:
45: General_Category -- (Letter|Mark|Number|Connector_Punctuation)
46:
47: \W non word char
48:
49: \s whitespace char
50:
51: Not Unicode:
52: \t, \n, \v, \f, \r, \x20
53:
54: Unicode:
55: 0009, 000A, 000B, 000C, 000D, 0085(NEL),
56: General_Category -- Line_Separator
57: -- Paragraph_Separator
58: -- Space_Separator
59:
60: \S non whitespace char
61:
62: \d decimal digit char
63:
64: Unicode: General_Category -- Decimal_Number
65:
66: \D non decimal digit char
67:
68: \h hexadecimal digit char [0-9a-fA-F]
69:
70: \H non hexadecimal digit char
71:
72:
73: 4. Quantifier
74:
75: greedy
76:
77: ? 1 or 0 times
78: * 0 or more times
79: + 1 or more times
80: {n,m} at least n but not more than m times
81: {n,} at least n times
82: {,n} at least 0 but not more than n times ({0,n})
83: {n} n times
84:
85: reluctant
86:
87: ?? 1 or 0 times
88: *? 0 or more times
89: +? 1 or more times
90: {n,m}? at least n but not more than m times
91: {n,}? at least n times
92: {,n}? at least 0 but not more than n times (== {0,n}?)
93:
94: possessive (greedy and does not backtrack after repeated)
95:
96: ?+ 1 or 0 times
97: *+ 0 or more times
98: ++ 1 or more times
99:
100: ({n,m}+, {n,}+, {n}+ are possessive op. in ONIG_SYNTAX_JAVA only)
101:
102: ex. /a*+/ === /(?>a*)/
103:
104:
105: 5. Anchors
106:
107: ^ beginning of the line
108: $ end of the line
109: \b word boundary
110: \B not word boundary
111: \A beginning of string
112: \Z end of string, or before newline at the end
113: \z end of string
114: \G matching start position (*)
115:
116: * Ruby Regexp:
117: previous end-of-match position
118: (This specification is not related to this library.)
119:
120:
121: 6. Character class
122:
123: ^... negative class (lowest precedence operator)
124: x-y range from x to y
125: [...] set (character class in character class)
126: ..&&.. intersection (low precedence at the next of ^)
127:
128: ex. [a-w&&[^c-g]z] ==> ([a-w] AND ([^c-g] OR z)) ==> [abh-w]
129:
130: * If you want to use '[', '-', ']' as a normal character
131: in a character class, you should escape these characters by '\'.
132:
133:
134: POSIX bracket ([:xxxxx:], negate [:^xxxxx:])
135:
136: Not Unicode Case:
137:
138: alnum alphabet or digit char
139: alpha alphabet
140: ascii code value: [0 - 127]
141: blank \t, \x20
142: cntrl
143: digit 0-9
144: graph include all of multibyte encoded characters
145: lower
146: print include all of multibyte encoded characters
147: punct
148: space \t, \n, \v, \f, \r, \x20
149: upper
150: xdigit 0-9, a-f, A-F
151:
152:
153: Unicode Case:
154:
155: alnum Letter | Mark | Decimal_Number
156: alpha Letter | Mark
157: ascii 0000 - 007F
158: blank Space_Separator | 0009
159: cntrl Control | Format | Unassigned | Private_Use | Surrogate
160: digit Decimal_Number
161: graph [[:^space:]] && ^Control && ^Unassigned && ^Surrogate
162: lower Lowercase_Letter
163: print [[:graph:]] | [[:space:]]
164: punct Connector_Punctuation | Dash_Punctuation | Close_Punctuation |
165: Final_Punctuation | Initial_Punctuation | Other_Punctuation |
166: Open_Punctuation
167: space Space_Separator | Line_Separator | Paragraph_Separator |
168: 0009 | 000A | 000B | 000C | 000D | 0085
169: upper Uppercase_Letter
170: xdigit 0030 - 0039 | 0041 - 0046 | 0061 - 0066
171: (0-9, a-f, A-F)
172:
173:
174: 7. Extended groups
175:
176: (?#...) comment
177:
178: (?imx-imx) option on/off
179: i: ignore case
180: m: multi-line (dot(.) match newline)
181: x: extended form
182: (?imx-imx:subexp) option on/off for subexp
183:
184: (?:subexp) not captured group
185: (subexp) captured group
186:
187: (?=subexp) look-ahead
188: (?!subexp) negative look-ahead
189: (?<=subexp) look-behind
190: (?<!subexp) negative look-behind
191:
192: Subexp of look-behind must be fixed character length.
193: But different character length is allowed in top level
194: alternatives only.
195: ex. (?<=a|bc) is OK. (?<=aaa(?:b|cd)) is not allowed.
196:
197: In negative-look-behind, captured group isn't allowed,
198: but shy group(?:) is allowed.
199:
200: (?>subexp) atomic group
201: don't backtrack in subexp.
202:
203: (?<name>subexp) define named group
204: (All characters of the name must be a word character.
205: And first character must not be a digit or uppper case)
206:
207: Not only a name but a number is assigned like a captured
208: group.
209:
210: Assigning the same name as two or more subexps is allowed.
211: In this case, a subexp call can not be performed although
212: the back reference is possible.
213:
214:
215: 8. Back reference
216:
217: \n back reference by group number (n >= 1)
218: \k<name> back reference by group name
219:
220: In the back reference by the multiplex definition name,
221: a subexp with a large number is referred to preferentially.
222: (When not matched, a group of the small number is referred to.)
223:
224: * Back reference by group number is forbidden if named group is defined
225: in the pattern and ONIG_OPTION_CAPTURE_GROUP is not setted.
226:
227:
228: back reference with nest level
229:
230: (This function is disabled in Ruby 1.9.)
231:
232: \k<name+n> n: 0, 1, 2, ...
233: \k<name-n> n: 0, 1, 2, ...
234:
235: Destinate relative nest level from back reference position.
236:
237: ex 1.
238:
239: /\A(?<a>|.|(?:(?<b>.)\g<a>\k<b+0>))\z/.match("reer")
240:
241: ex 2.
242:
243: r = Regexp.compile(<<'__REGEXP__'.strip, Regexp::EXTENDED)
244: (?<element> \g<stag> \g<content>* \g<etag> ){0}
245: (?<stag> < \g<name> \s* > ){0}
246: (?<name> [a-zA-Z_:]+ ){0}
247: (?<content> [^<&]+ (\g<element> | [^<&]+)* ){0}
248: (?<etag> </ \k<name+1> >){0}
249: \g<element>
250: __REGEXP__
251:
252: p r.match('<foo>f<bar>bbb</bar>f</foo>').captures
253:
254:
255:
256: 9. Subexp call ("Tanaka Akira special")
257:
258: \g<name> call by group name
259: \g<n> call by group number (n >= 1)
260:
261: * left-most recursive call is not allowed.
262: ex. (?<name>a|\g<name>b) => error
263: (?<name>a|b\g<name>c) => OK
264:
265: * Call by group number is forbidden if named group is defined in the pattern
266: and ONIG_OPTION_CAPTURE_GROUP is not setted.
267:
268: * If the option status of called group is different from calling position
269: then the group's option is effective.
270:
271: ex. (?-i:\g<name>)(?i:(?<name>a)){0} match to "A"
272:
273:
274: 10. Captured group
275:
276: Behavior of the no-named group (...) changes with the following conditions.
277: (But named group is not changed.)
278:
279: case 1. /.../ (named group is not used, no option)
280:
281: (...) is treated as a captured group.
282:
283: case 2. /.../g (named group is not used, 'g' option)
284:
285: (...) is treated as a no-captured group (?:...).
286:
287: case 3. /..(?<name>..)../ (named group is used, no option)
288:
289: (...) is treated as a no-captured group (?:...).
290: numbered-backref/call is not allowed.
291:
292: case 4. /..(?<name>..)../G (named group is used, 'G' option)
293:
294: (...) is treated as a captured group.
295: numbered-backref/call is allowed.
296:
297: where
298: g: ONIG_OPTION_DONT_CAPTURE_GROUP
299: G: ONIG_OPTION_CAPTURE_GROUP
300:
301: ('g' and 'G' options are argued in ruby-dev ML)
302:
303: These options are not implemented in Ruby level.
304:
305:
306: -----------------------------
307: A-1. Syntax depend options
308:
309: + ONIG_SYNTAX_RUBY
310: (?m): dot(.) match newline
311:
312: + ONIG_SYNTAX_PERL and ONIG_SYNTAX_JAVA
313: (?s): dot(.) match newline
314: (?m): ^ match after newline, $ match before newline
315:
316:
317: A-2. Original extensions
318:
319: + hexadecimal digit char type \h, \H
320: + named group (?<name>...)
321: + named backref \k<name>
322: + subexp call \g<name>, \g<group-num>
323:
324:
325: A-3. Lacked features compare with perl 5.8.0
326:
327: + [:word:]
328: + \N{name}
329: + \l,\u,\L,\U, \X, \C
330: + (?{code})
331: + (??{code})
332: + (?(condition)yes-pat|no-pat)
333:
334: * \Q...\E
335: This is effective on ONIG_SYNTAX_PERL and ONIG_SYNTAX_JAVA.
336:
337: * \p{property}, \P{property}
338: This is effective on ONIG_SYNTAX_PERL and ONIG_SYNTAX_JAVA.
339: Alnum, Alpha, Blank, Cntrl, Digit, Graph, Lower,
340: Print, Punct, Space, Upper, XDigit, ASCII are supported.
341:
342: Prefix 'Is' of property name is allowed in ONIG_SYNTAX_PERL only.
343: ex. \p{IsXDigit}.
344:
345: Negation operator of property is supported in ONIG_SYNTAX_PERL only.
346: \p{^...}, \P{^...}
347:
348:
349: A-4. Differences with Japanized GNU regex(version 0.12) of Ruby
350:
351: + add hexadecimal digit char type (\h, \H)
352: + add look-behind
353: (?<=fixed-char-length-pattern), (?<!fixed-char-length-pattern)
354: + add possessive quantifier. ?+, *+, ++
355: + add operations in character class. [], &&
356: ('[' must be escaped as an usual char in character class.)
357: + add named group and subexp call.
358: + octal or hexadecimal number sequence can be treated as
359: a multibyte code char in character class if multibyte encoding
360: is specified.
361: (ex. [\xa1\xa2], [\xa1\xa7-\xa4\xa1])
362: + allow the range of single byte char and multibyte char in character
363: class.
364: ex. /[a-<<any EUC-JP character>>]/ in EUC-JP encoding.
365: + effect range of isolated option is to next ')'.
366: ex. (?:(?i)a|b) is interpreted as (?:(?i:a|b)), not (?:(?i:a)|b).
367: + isolated option is not transparent to previous pattern.
368: ex. a(?i)* is a syntax error pattern.
369: + allowed incompleted left brace as an usual string.
370: ex. /{/, /({)/, /a{2,3/ etc...
371: + negative POSIX bracket [:^xxxx:] is supported.
372: + POSIX bracket [:ascii:] is added.
373: + repeat of look-ahead is not allowed.
374: ex. /(?=a)*/, /(?!b){5}/
375: + Ignore case option is effective to numbered character.
376: ex. /\x61/i =~ "A"
377: + In the range quantifier, the number of the minimum is omissible.
378: /a{,n}/ == /a{0,n}/
379: The simultanious abbreviation of the number of times of the minimum
380: and the maximum is not allowed. (/a{,}/)
381: + /a{n}?/ is not a non-greedy operator.
382: /a{n}?/ == /(?:a{n})?/
383: + invalid back reference is checked and cause error.
384: /\1/, /(a)\2/
385: + Zero-length match in infinite repeat stops the repeat,
386: then changes of the capture group status are checked as stop condition.
387: /(?:()|())*\1\2/ =~ ""
388: /(?:\1a|())*/ =~ "a"
389:
390:
391: A-5. Disabled functions by default syntax
392:
393: + capture history
394:
395: (?@...) and (?@<name>...)
396:
397: ex. /(?@a)*/.match("aaa") ==> [<0-1>, <1-2>, <2-3>]
398:
399: see sample/listcap.c file.
400:
401:
402: A-6. Problems
403:
404: + Invalid encoding byte sequence is not checked in UTF-8.
405:
406: * Invalid first byte is treated as a character.
407: /./u =~ "\xa3"
408:
409: * Incomplete byte sequence is not checked.
410: /\w+/ =~ "a\xf3\x8ec"
411:
412: // END
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>
![[BACK]](/icons/cvsweb/back.gif){kind=icon}
Return to RE CVS log ![[TXT]](/icons/cvsweb/text.gif){kind=icon}
![[DIR]](/icons/cvsweb/dir.gif){kind=icon}
Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / php / ext / mbstring / oniguruma / doc