string-metric/dist/Damerau.js

Get string similarity in JavaScript or TypeScript

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.Damerau = void 0;
var utils_1 = require("./utils/utils");
var Damerau = /** @class */ (function () {
    function Damerau() {
    }
    Damerau.prototype.distance = function (s1, s2) {
        if (utils_1.isNullOrUndefined(s1)) {
            throw new Error('s1 must neither be null nor undefined');
        }
        if (utils_1.isNullOrUndefined(s2)) {
            throw new Error('s2 must neither be null nor undefined');
        }
        if (s1 === s2) {
            return 0;
        }
        var inf = s1.length + s2.length;
        var da = new Map();
        for (var d = 0; d < s1.length; d++) {
            da.set(s1[d], 0);
        }
        for (var d = 0; d < s2.length; d++) {
            da.set(s2[d], 0);
        }
        var h = utils_1.createTwoDimensionalArray(s1.length + 2, s2.length + 2);
        for (var i = 0; i <= s1.length; i++) {
            h[i + 1][0] = inf;
            h[i + 1][1] = i;
        }
        for (var j = 0; j <= s2.length; j++) {
            h[0][j + 1] = inf;
            h[1][j + 1] = j;
        }
        for (var i = 1; i <= s1.length; i++) {
            var db = 0;
            for (var j = 1; j <= s2.length; j++) {
                var i1 = da.get(s2[j - 1]);
                var j1 = db;
                var cost = 1;
                if (s1[i - 1] === s2[j - 1]) {
                    cost = 0;
                    db = j;
                }
                h[i + 1][j + 1] = this.min(h[i][j] + cost, h[i + 1][j] + 1, h[i][j + 1] + 1, h[i1][j1] + (i - i1 - 1) + 1 + (j - j1 - 1));
            }
            da.set(s1[i - 1], i);
        }
        return h[s1.length + 1][s2.length + 1];
    };
    Damerau.prototype.min = function (a, b, c, d) {
        return this.minWithNaN(a, this.minWithNaN(b, this.minWithNaN(c, d)));
    };
    Damerau.prototype.minWithNaN = function (a, b) {
        if (isNaN(a) && isNaN(b)) {
            return 0;
        }
        if (isNaN(a)) {
            return b;
        }
        if (isNaN(b)) {
            return a;
        }
        return Math.min(a, b);
    };
    return Damerau;
}());
exports.Damerau = Damerau;