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Direktori : /lib/node_modules/pm2/node_modules/fast-levenshtein/ |
Current File : //lib/node_modules/pm2/node_modules/fast-levenshtein/levenshtein.js |
(function() { 'use strict'; var collator; try { collator = (typeof Intl !== "undefined" && typeof Intl.Collator !== "undefined") ? Intl.Collator("generic", { sensitivity: "base" }) : null; } catch (err){ console.log("Collator could not be initialized and wouldn't be used"); } // arrays to re-use var prevRow = [], str2Char = []; /** * Based on the algorithm at http://en.wikipedia.org/wiki/Levenshtein_distance. */ var Levenshtein = { /** * Calculate levenshtein distance of the two strings. * * @param str1 String the first string. * @param str2 String the second string. * @param [options] Additional options. * @param [options.useCollator] Use `Intl.Collator` for locale-sensitive string comparison. * @return Integer the levenshtein distance (0 and above). */ get: function(str1, str2, options) { var useCollator = (options && collator && options.useCollator); var str1Len = str1.length, str2Len = str2.length; // base cases if (str1Len === 0) return str2Len; if (str2Len === 0) return str1Len; // two rows var curCol, nextCol, i, j, tmp; // initialise previous row for (i=0; i<str2Len; ++i) { prevRow[i] = i; str2Char[i] = str2.charCodeAt(i); } prevRow[str2Len] = str2Len; var strCmp; if (useCollator) { // calculate current row distance from previous row using collator for (i = 0; i < str1Len; ++i) { nextCol = i + 1; for (j = 0; j < str2Len; ++j) { curCol = nextCol; // substution strCmp = 0 === collator.compare(str1.charAt(i), String.fromCharCode(str2Char[j])); nextCol = prevRow[j] + (strCmp ? 0 : 1); // insertion tmp = curCol + 1; if (nextCol > tmp) { nextCol = tmp; } // deletion tmp = prevRow[j + 1] + 1; if (nextCol > tmp) { nextCol = tmp; } // copy current col value into previous (in preparation for next iteration) prevRow[j] = curCol; } // copy last col value into previous (in preparation for next iteration) prevRow[j] = nextCol; } } else { // calculate current row distance from previous row without collator for (i = 0; i < str1Len; ++i) { nextCol = i + 1; for (j = 0; j < str2Len; ++j) { curCol = nextCol; // substution strCmp = str1.charCodeAt(i) === str2Char[j]; nextCol = prevRow[j] + (strCmp ? 0 : 1); // insertion tmp = curCol + 1; if (nextCol > tmp) { nextCol = tmp; } // deletion tmp = prevRow[j + 1] + 1; if (nextCol > tmp) { nextCol = tmp; } // copy current col value into previous (in preparation for next iteration) prevRow[j] = curCol; } // copy last col value into previous (in preparation for next iteration) prevRow[j] = nextCol; } } return nextCol; } }; // amd if (typeof define !== "undefined" && define !== null && define.amd) { define(function() { return Levenshtein; }); } // commonjs else if (typeof module !== "undefined" && module !== null && typeof exports !== "undefined" && module.exports === exports) { module.exports = Levenshtein; } // web worker else if (typeof self !== "undefined" && typeof self.postMessage === 'function' && typeof self.importScripts === 'function') { self.Levenshtein = Levenshtein; } // browser main thread else if (typeof window !== "undefined" && window !== null) { window.Levenshtein = Levenshtein; } }());