1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
|
//> This file is part of Ymacs, an Emacs-like editor for the Web
//> http://www.ymacs.org/
//>
//> Copyright (c) 2009-2010, Mihai Bazon, Dynarch.com. All rights reserved.
//>
//> Redistribution and use in source and binary forms, with or without
//> modification, are permitted provided that the following conditions are
//> met:
//>
//> * Redistributions of source code must retain the above copyright
//> notice, this list of conditions and the following disclaimer.
//>
//> * Redistributions in binary form must reproduce the above copyright
//> notice, this list of conditions and the following disclaimer in
//> the documentation and/or other materials provided with the
//> distribution.
//>
//> * Neither the name of Dynarch.com nor the names of its contributors
//> may be used to endorse or promote products derived from this
//> software without specific prior written permission.
//>
//> THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER “AS IS” AND ANY
//> EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
//> IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
//> PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE
//> FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
//> CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
//> SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
//> INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
//> CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
//> ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
//> THE POSSIBILITY OF SUCH DAMAGE.
// @require ymacs.js
window.Ymacs_Regexp = (function(){
var SEARCH_BACKWARD = {};
// var LOOKING_BACK = {};
function getPatternAndFlags(rx) {
if (rx instanceof RegExp)
rx = rx.toString();
var pos = rx.lastIndexOf("/"), flags = "";
flags = rx.substr(pos + 1);
rx = rx.substring(1, pos);
return { pattern: rx, flags: flags };
};
return {
// Prepends to the regexp a token that will greedily eat any characters in
// front of the pattern. This is useful to get the last occurrence of the
// pattern in a string. The returned regexp is cached, so it's not
// reconstructed a second time.
//
// A function using such regexp must be aware that m.index will always be zero,
// because it matches from the beginning of the string. To find the index of
// the real match, it should use m[0].length (where m is an array returned by
// rx.exec()).
search_backward: function(rx) {
var key = rx.toString();
var cached = SEARCH_BACKWARD[key];
if (!cached) {
rx = getPatternAndFlags(key);
rx.flags = rx.flags.replace(/g/g, "") + "g"; // make sure it's global
cached = new RegExp("([^]*)(" + rx.pattern + ")", rx.flags);
SEARCH_BACKWARD[key] = cached;
}
cached.lastIndex = 0;
return cached;
}
// Returns a regexp that has the "$" appended, so that it would match only at
// the end of the string. This should be faster than using search_backward and
// checking the lastIndex, since the JS regexp engine can optimize it, knowing
// that it should match only at the end of the string. Well, I hope.
//
// Update: it's not faster, and it's buggy. Don't use this.
//
// looking_back: function(rx) {
// var key = rx.toString();
// var cached = LOOKING_BACK[key];
// if (!cached) {
// rx = getPatternAndFlags(key);
// rx.pattern = rx.pattern.replace(/\$*$/, "$");
// cached = new RegExp(rx.pattern, rx.flags);
// LOOKING_BACK[key] = cached;
// }
// return cached;
// }
};
})();
|