string-metric/dist/Levenshtein.js

Get string similarity in JavaScript or TypeScript

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.Levenshtein = void 0;
var utils_1 = require("./utils/utils");
var Levenshtein = /** @class */ (function () {
    function Levenshtein() {
    }
    Levenshtein.prototype.distance = function (s1, s2, limit) {
        if (limit === void 0) { limit = Number.MAX_VALUE; }
        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;
        }
        if (s1.length === 0) {
            return s2.length;
        }
        if (s2.length === 0) {
            return s1.length;
        }
        var v0 = Array(s2.length + 1);
        var v1 = Array(s2.length + 1);
        var vtemp = [];
        for (var i = 0; i < v0.length; i++) {
            v0[i] = i;
        }
        for (var i = 0; i < s1.length; i++) {
            v1[0] = i + 1;
            var minv1 = v1[0];
            for (var j = 0; j < s2.length; j++) {
                var cost = 1;
                if (s1[i] === s2[j]) {
                    cost = 0;
                }
                v1[j + 1] = Math.min(v1[j] + 1, Math.min(v0[j + 1] + 1, v0[j] + cost));
                minv1 = Math.min(minv1, v1[j + 1]);
            }
            if (minv1 >= limit) {
                return limit;
            }
            vtemp = v0;
            v0 = v1;
            v1 = vtemp;
        }
        return v0[s2.length];
    };
    return Levenshtein;
}());
exports.Levenshtein = Levenshtein;