codsworth-namegen/src/main/js/jaro-winkler.js

118 lines
3.2 KiB
JavaScript

/**
* The MIT License (MIT)
*
* Copyright (c) 2015 Jordan Thomas
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
"use strict";
const optionDefault = (template, options) => {
for (let prop in options)
if (options.hasOwnProperty(prop))
template[prop] = options[prop];
return template;
};
export const jaro_winkler = function (a, b, options) {
// Load default options
options = optionDefault({"caseSensitive": true}, options);
// Convert to lowercase if not case-sensitive
if (!options.caseSensitive) {
a = a.toLowerCase();
b = b.toLowerCase();
}
const aLen = a.length;
const bLen = b.length;
// Short-circuit if either is empty
if (aLen === 0 || bLen === 0)
return 0;
// Short-circuit if exact match
if (a === b)
return 1;
// Calculate difference
const range = (Math.floor(Math.max(aLen, bLen) / 2)) - 1;
const aMatches = [];
const bMatches = [];
let low;
let high;
let m = 0;
// Find matches
for (let i = 0; i < aLen; i++) {
low = ((i >= range) ? i - range : 0);
high = ((i + range <= bLen) ? (i + range) : (bLen - 1));
for (let j = low; j <= high; j++) {
if (aMatches[i] !== true && bMatches[j] !== true && a[i] === b[j]) {
aMatches[i] = true;
bMatches[j] = true;
m++;
break;
}
}
}
// Short-circuit if not matches found
if (m === 0)
return 0;
// Count transpositions
let k = 0;
let numTrans = 0;
for (let i = 0; i < aLen; i++) {
if (aMatches[i] === true) {
let j;
for (j = k; j < bLen; j++) {
if (bMatches[j] === true) {
k = j + 1;
break;
}
}
if (a[i] !== b[j]) {
numTrans++;
}
}
}
let weight = (((m / aLen) + (m / bLen) + (m - (numTrans / 2)) / m) / 3);
let l = 0;
const p = 0.1;
if (weight > 0.7) {
while (a[l] === b[l] && l < 4)
l++;
weight += l * p * (1 - weight);
}
return weight;
};