94 lines
2.5 KiB
JavaScript
94 lines
2.5 KiB
JavaScript
/**
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* The MIT License (MIT)
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*
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* Copyright (c) 2011 Andrei Mackenzie
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*/
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"use strict";
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var levenshtein = function(a, b, options)
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{
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// Load default options
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options = optionDefault(
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{
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"caseSensitive" : true
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},
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options
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);
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// Convert to lowercase if not case-sensitive
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if(!options.caseSensitive)
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{
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a = a.toLowerCase();
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b = b.toLowerCase();
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}
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var alen = a.length,
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blen = b.length;
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if(alen == 0)
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{
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return blen;
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}
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if(blen == 0)
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{
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return alen;
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}
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var matrix = [];
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// Increment along the first column of each row
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for(var i = 0; i <= blen; i++)
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{
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matrix[i] = [i];
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}
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// Increment each column in the first row
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for(var j = 0; j <= alen; j++)
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{
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matrix[0][j] = j;
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}
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// Fill in the rest of the matrix
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for(i = 1; i <= blen; i++)
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{
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for(j = 1; j <= alen; j++)
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{
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if(b.charAt(i - 1) == a.charAt(j - 1))
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{
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matrix[i][j] = matrix[i - 1][j - 1];
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}
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else
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{
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matrix[i][j] =
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min(
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matrix[i - 1][j - 1] + 1, // Substitution
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matrix[i][j - 1] + 1, // Insertion
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matrix[i - 1][j] + 1 // Deletion
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);
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}
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}
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}
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return matrix[blen][alen];
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};
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