Wed, 31 Dec 2014 07:53:36 +0100
Correct small whitespace inconsistency, lost while renaming variables.
michael@0 | 1 | /* |
michael@0 | 2 | Copyright (c) 2006 Lawrence Oluyede <l.oluyede@gmail.com> |
michael@0 | 3 | |
michael@0 | 4 | Permission is hereby granted, free of charge, to any person obtaining a copy |
michael@0 | 5 | of this software and associated documentation files (the "Software"), to deal |
michael@0 | 6 | in the Software without restriction, including without limitation the rights |
michael@0 | 7 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
michael@0 | 8 | copies of the Software, and to permit persons to whom the Software is |
michael@0 | 9 | furnished to do so, subject to the following conditions: |
michael@0 | 10 | |
michael@0 | 11 | The above copyright notice and this permission notice shall be included in all |
michael@0 | 12 | copies or substantial portions of the Software. |
michael@0 | 13 | |
michael@0 | 14 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
michael@0 | 15 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
michael@0 | 16 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
michael@0 | 17 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
michael@0 | 18 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
michael@0 | 19 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
michael@0 | 20 | SOFTWARE. |
michael@0 | 21 | */ |
michael@0 | 22 | |
michael@0 | 23 | /* |
michael@0 | 24 | startsWith(str, prefix[, start[, end]]) -> bool |
michael@0 | 25 | |
michael@0 | 26 | Return true if str ends with the specified prefix, false otherwise. |
michael@0 | 27 | With optional start, test str beginning at that position. |
michael@0 | 28 | With optional end, stop comparing str at that position. |
michael@0 | 29 | prefix can also be an array of strings to try. |
michael@0 | 30 | */ |
michael@0 | 31 | |
michael@0 | 32 | var EXPORTED_SYMBOLS = ['startsWith', 'endsWith']; |
michael@0 | 33 | |
michael@0 | 34 | function startsWith(str, prefix, start, end) { |
michael@0 | 35 | if (arguments.length < 2) { |
michael@0 | 36 | throw new TypeError('startsWith() requires at least 2 arguments'); |
michael@0 | 37 | } |
michael@0 | 38 | |
michael@0 | 39 | // check if start and end are null/undefined or a 'number' |
michael@0 | 40 | if ((start == null) || (isNaN(new Number(start)))) { |
michael@0 | 41 | start = 0; |
michael@0 | 42 | } |
michael@0 | 43 | if ((end == null) || (isNaN(new Number(end)))) { |
michael@0 | 44 | end = Number.MAX_VALUE; |
michael@0 | 45 | } |
michael@0 | 46 | |
michael@0 | 47 | // if it's an array |
michael@0 | 48 | if (typeof prefix == "object") { |
michael@0 | 49 | for (var i = 0, j = prefix.length; i < j; i++) { |
michael@0 | 50 | var res = _stringTailMatch(str, prefix[i], start, end, true); |
michael@0 | 51 | if (res) { |
michael@0 | 52 | return true; |
michael@0 | 53 | } |
michael@0 | 54 | } |
michael@0 | 55 | return false; |
michael@0 | 56 | } |
michael@0 | 57 | |
michael@0 | 58 | return _stringTailMatch(str, prefix, start, end, true); |
michael@0 | 59 | } |
michael@0 | 60 | |
michael@0 | 61 | /* |
michael@0 | 62 | endsWith(str, suffix[, start[, end]]) -> bool |
michael@0 | 63 | |
michael@0 | 64 | Return true if str ends with the specified suffix, false otherwise. |
michael@0 | 65 | With optional start, test str beginning at that position. |
michael@0 | 66 | With optional end, stop comparing str at that position. |
michael@0 | 67 | suffix can also be an array of strings to try. |
michael@0 | 68 | */ |
michael@0 | 69 | function endsWith(str, suffix, start, end) { |
michael@0 | 70 | if (arguments.length < 2) { |
michael@0 | 71 | throw new TypeError('endsWith() requires at least 2 arguments'); |
michael@0 | 72 | } |
michael@0 | 73 | |
michael@0 | 74 | // check if start and end are null/undefined or a 'number' |
michael@0 | 75 | if ((start == null) || (isNaN(new Number(start)))) { |
michael@0 | 76 | start = 0; |
michael@0 | 77 | } |
michael@0 | 78 | if ((end == null) || (isNaN(new Number(end)))) { |
michael@0 | 79 | end = Number.MAX_VALUE; |
michael@0 | 80 | } |
michael@0 | 81 | |
michael@0 | 82 | // if it's an array |
michael@0 | 83 | if (typeof suffix == "object") { |
michael@0 | 84 | for (var i = 0, j = suffix.length; i < j; i++) { |
michael@0 | 85 | var res = _stringTailMatch(str, suffix[i], start, end, false); |
michael@0 | 86 | if (res) { |
michael@0 | 87 | return true; |
michael@0 | 88 | } |
michael@0 | 89 | } |
michael@0 | 90 | return false; |
michael@0 | 91 | } |
michael@0 | 92 | |
michael@0 | 93 | return _stringTailMatch(str, suffix, start, end, false); |
michael@0 | 94 | } |
michael@0 | 95 | |
michael@0 | 96 | /* |
michael@0 | 97 | Matches the end (direction == false) or start (direction == true) of str |
michael@0 | 98 | against substr, using the start and end arguments. Returns false |
michael@0 | 99 | if not found and true if found. |
michael@0 | 100 | */ |
michael@0 | 101 | function _stringTailMatch(str, substr, start, end, fromStart) { |
michael@0 | 102 | var len = str.length; |
michael@0 | 103 | var slen = substr.length; |
michael@0 | 104 | |
michael@0 | 105 | var indices = _adjustIndices(start, end, len); |
michael@0 | 106 | start = indices[0]; end = indices[1]; len = indices[2]; |
michael@0 | 107 | |
michael@0 | 108 | if (fromStart) { |
michael@0 | 109 | if (start + slen > len) { |
michael@0 | 110 | return false; |
michael@0 | 111 | } |
michael@0 | 112 | } else { |
michael@0 | 113 | if (end - start < slen || start > len) { |
michael@0 | 114 | return false; |
michael@0 | 115 | } |
michael@0 | 116 | if (end - slen > start) { |
michael@0 | 117 | start = end - slen; |
michael@0 | 118 | } |
michael@0 | 119 | } |
michael@0 | 120 | |
michael@0 | 121 | if (end - start >= slen) { |
michael@0 | 122 | return str.substr(start, slen) == substr; |
michael@0 | 123 | } |
michael@0 | 124 | return false; |
michael@0 | 125 | } |
michael@0 | 126 | |
michael@0 | 127 | function _adjustIndices(start, end, len) |
michael@0 | 128 | { |
michael@0 | 129 | if (end > len) { |
michael@0 | 130 | end = len; |
michael@0 | 131 | } else if (end < 0) { |
michael@0 | 132 | end += len; |
michael@0 | 133 | } |
michael@0 | 134 | |
michael@0 | 135 | if (end < 0) { |
michael@0 | 136 | end = 0; |
michael@0 | 137 | } |
michael@0 | 138 | if (start < 0) { |
michael@0 | 139 | start += len; |
michael@0 | 140 | } |
michael@0 | 141 | if (start < 0) { |
michael@0 | 142 | start = 0; |
michael@0 | 143 | } |
michael@0 | 144 | |
michael@0 | 145 | return [start, end, len]; |
michael@0 | 146 | } |