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70 lines
1.6 KiB
70 lines
1.6 KiB
/*
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* A naive implementation never finishes matching: '(x*)*' against the input 'y',
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* because eventually the inner quantifier would match the empty string, which
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* would then match forever. Other empty quantifier cases are also tested.
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*
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* Note that Python rejects such regexps:
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*
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* >>> re.compile(r'(x*)*')
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* Traceback (most recent call last):
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* File "<stdin>", line 1, in <module>
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* File "/usr/lib/python2.6/re.py", line 190, in compile
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* return _compile(pattern, flags)
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* File "/usr/lib/python2.6/re.py", line 245, in _compile
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* raise error, v # invalid expression
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* sre_constants.error: nothing to repeat
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*
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*/
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var t;
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/*===
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xxx xxx
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string
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string
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string
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string
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===*/
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/* greedy matching, (x*) will match 'xxx', outer quantifier will repeat once */
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t = /(x*)*/.exec('xxx');
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print(t[0], t[1]);
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/* here x* should match zero times, leaving (x*) capture the empty string */
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t = /(x*)*/.exec('y');
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print(t[0], typeof t[0]);
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print(t[1], typeof t[1]);
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/* same as above */
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t = /(x*)*/.exec('');
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print(t[0], typeof t[0]);
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print(t[1], typeof t[1]);
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/*===
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xyz string
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xyz string
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null object
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xyz string
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xyz string
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null object
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===*/
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t = /(?:(?=x)){1000}xyz/.exec('xyz');
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print(t[0], typeof t[0]);
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t = /(?:(?=x)){1000}xyz/.exec('xyyxyz');
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print(t[0], typeof t[0]);
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t = /(?:(?=x)){1000}xyz/.exec('xyy');
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print(t, typeof t);
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t = /(?:(?=x))+xyz/.exec('xyz');
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print(t[0], typeof t[0]);
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t = /(?:(?=x))+xyz/.exec('xyyxyz');
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print(t[0], typeof t[0]);
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t = /(?:(?=x))+xyz/.exec('xy');
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print(t, typeof t);
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/* XXX: check behavior against E5 specification, both Rhino and Smjs fail */
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