8889841cREADME.md000066600000005272150441740370006042 0ustar00# fastest-levenshtein :rocket: > Fastest JS/TS implemenation of [Levenshtein distance](https://en.wikipedia.org/wiki/Levenshtein_distance).
> Measure the difference between two strings. [![Build Status](https://travis-ci.org/ka-weihe/fastest-levenshtein.svg?branch=master)](https://travis-ci.org/ka-weihe/fastest-levenshtein) [![Coverage Status](https://coveralls.io/repos/github/ka-weihe/node-levenshtein/badge.svg?branch=master)](https://coveralls.io/github/ka-weihe/node-levenshtein?branch=master) [![Language grade: JavaScript](https://img.shields.io/lgtm/grade/javascript/g/ka-weihe/fastest-levenshtein.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/ka-weihe/fastest-levenshtein/context:javascript) ![npm](https://img.shields.io/npm/dm/fastest-levenshtein) ```bash $ npm i fastest-levenshtein ``` ## Usage ### Node ```javascript const {distance, closest} = require('fastest-levenshtein') // Print levenshtein-distance between 'fast' and 'faster' console.log(distance('fast', 'faster')) //=> 2 // Print string from array with lowest edit-distance to 'fast' console.log(closest('fast', ['slow', 'faster', 'fastest'])) //=> 'faster' ``` ### Deno ```javascript import {distance, closest} from 'https://deno.land/x/fastest_levenshtein/mod.ts' // Print levenshtein-distance between 'fast' and 'faster' console.log(distance('fast', 'faster')) //=> 2 // Print string from array with lowest edit-distance to 'fast' console.log(closest('fast', ['slow', 'faster', 'fastest'])) //=> 'faster' ``` ## Benchmark I generated 500 pairs of strings with length N. I measured the ops/sec each library achieves to process all the given pairs. Higher is better. | Test Target | N=4 | N=8 | N=16 | N=32 | N=64 | N=128 | N=256 | N=512 | N=1024 | |---------------------------|-------|-------|-------|------|-------|-------|-------|-------|--------| | fastest-levenshtein | 44423 | 23702 | 10764 | 4595 | 1049 | 291.5 | 86.64 | 22.24 | 5.473 | | js-levenshtein | 21261 | 10030 | 2939 | 824 | 223 | 57.62 | 14.77 | 3.717 | 0.934 | | leven | 19688 | 6884 | 1606 | 436 | 117 | 30.34 | 7.604 | 1.929 | 0.478 | | fast-levenshtein | 18577 | 6112 | 1265 | 345 | 89.41 | 22.70 | 5.676 | 1.428 | 0.348 | | levenshtein-edit-distance | 22968 | 7445 | 1493 | 409 | 109 | 28.07 | 7.095 | 1.789 | 0.445 | ### Relative Performance This image shows the relative performance between `fastest-levenshtein` and `js-levenshtein` (the 2nd fastest). `fastest-levenshtein` is always a lot faster. y-axis shows "times faster". ![Benchmark](/images/relaperf.png) ## License This project is licensed under the MIT License - see the [LICENSE.md](LICENSE.md) file for details LICENSE.md000066600000002060150441740370006157 0ustar00MIT License Copyright (c) 2020 Kasper Unn Weihe 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.mod.js000066600000007302150441740370005674 0ustar00"use strict"; exports.__esModule = true; exports.distance = exports.closest = void 0; var peq = new Uint32Array(0x10000); var myers_32 = function (a, b) { var n = a.length; var m = b.length; var lst = 1 << (n - 1); var pv = -1; var mv = 0; var sc = n; var i = n; while (i--) { peq[a.charCodeAt(i)] |= 1 << i; } for (i = 0; i < m; i++) { var eq = peq[b.charCodeAt(i)]; var xv = eq | mv; eq |= ((eq & pv) + pv) ^ pv; mv |= ~(eq | pv); pv &= eq; if (mv & lst) { sc++; } if (pv & lst) { sc--; } mv = (mv << 1) | 1; pv = (pv << 1) | ~(xv | mv); mv &= xv; } i = n; while (i--) { peq[a.charCodeAt(i)] = 0; } return sc; }; var myers_x = function (b, a) { var n = a.length; var m = b.length; var mhc = []; var phc = []; var hsize = Math.ceil(n / 32); var vsize = Math.ceil(m / 32); for (var i = 0; i < hsize; i++) { phc[i] = -1; mhc[i] = 0; } var j = 0; for (; j < vsize - 1; j++) { var mv_1 = 0; var pv_1 = -1; var start_1 = j * 32; var vlen_1 = Math.min(32, m) + start_1; for (var k = start_1; k < vlen_1; k++) { peq[b.charCodeAt(k)] |= 1 << k; } for (var i = 0; i < n; i++) { var eq = peq[a.charCodeAt(i)]; var pb = (phc[(i / 32) | 0] >>> i) & 1; var mb = (mhc[(i / 32) | 0] >>> i) & 1; var xv = eq | mv_1; var xh = ((((eq | mb) & pv_1) + pv_1) ^ pv_1) | eq | mb; var ph = mv_1 | ~(xh | pv_1); var mh = pv_1 & xh; if ((ph >>> 31) ^ pb) { phc[(i / 32) | 0] ^= 1 << i; } if ((mh >>> 31) ^ mb) { mhc[(i / 32) | 0] ^= 1 << i; } ph = (ph << 1) | pb; mh = (mh << 1) | mb; pv_1 = mh | ~(xv | ph); mv_1 = ph & xv; } for (var k = start_1; k < vlen_1; k++) { peq[b.charCodeAt(k)] = 0; } } var mv = 0; var pv = -1; var start = j * 32; var vlen = Math.min(32, m - start) + start; for (var k = start; k < vlen; k++) { peq[b.charCodeAt(k)] |= 1 << k; } var score = m; for (var i = 0; i < n; i++) { var eq = peq[a.charCodeAt(i)]; var pb = (phc[(i / 32) | 0] >>> i) & 1; var mb = (mhc[(i / 32) | 0] >>> i) & 1; var xv = eq | mv; var xh = ((((eq | mb) & pv) + pv) ^ pv) | eq | mb; var ph = mv | ~(xh | pv); var mh = pv & xh; score += (ph >>> (m - 1)) & 1; score -= (mh >>> (m - 1)) & 1; if ((ph >>> 31) ^ pb) { phc[(i / 32) | 0] ^= 1 << i; } if ((mh >>> 31) ^ mb) { mhc[(i / 32) | 0] ^= 1 << i; } ph = (ph << 1) | pb; mh = (mh << 1) | mb; pv = mh | ~(xv | ph); mv = ph & xv; } for (var k = start; k < vlen; k++) { peq[b.charCodeAt(k)] = 0; } return score; }; var distance = function (a, b) { if (a.length < b.length) { var tmp = b; b = a; a = tmp; } if (b.length === 0) { return a.length; } if (a.length <= 32) { return myers_32(a, b); } return myers_x(a, b); }; exports.distance = distance; var closest = function (str, arr) { var min_distance = Infinity; var min_index = 0; for (var i = 0; i < arr.length; i++) { var dist = distance(str, arr[i]); if (dist < min_distance) { min_distance = dist; min_index = i; } } return arr[min_index]; }; exports.closest = closest; .prettierrc000066600000000050150441740370006734 0ustar00{ "tabWidth": 2, "useTabs": false } .travis.yml000066600000000254150441740370006667 0ustar00sudo: false language: node_js os: - linux - osx - windows arch: amd64 node_js: - 14 - 13 - 12 - 11 - 10 script: - npm test - npm run test:coverallsmod.d.ts000066600000000240150441740370006122 0ustar00declare const distance: (a: string, b: string) => number; declare const closest: (str: string, arr: readonly string[]) => string; export { closest, distance }; esm/mod.js000066600000007124150441740370006462 0ustar00const peq = new Uint32Array(0x10000); const myers_32 = (a, b) => { const n = a.length; const m = b.length; const lst = 1 << (n - 1); let pv = -1; let mv = 0; let sc = n; let i = n; while (i--) { peq[a.charCodeAt(i)] |= 1 << i; } for (i = 0; i < m; i++) { let eq = peq[b.charCodeAt(i)]; const xv = eq | mv; eq |= ((eq & pv) + pv) ^ pv; mv |= ~(eq | pv); pv &= eq; if (mv & lst) { sc++; } if (pv & lst) { sc--; } mv = (mv << 1) | 1; pv = (pv << 1) | ~(xv | mv); mv &= xv; } i = n; while (i--) { peq[a.charCodeAt(i)] = 0; } return sc; }; const myers_x = (b, a) => { const n = a.length; const m = b.length; const mhc = []; const phc = []; const hsize = Math.ceil(n / 32); const vsize = Math.ceil(m / 32); for (let i = 0; i < hsize; i++) { phc[i] = -1; mhc[i] = 0; } let j = 0; for (; j < vsize - 1; j++) { let mv = 0; let pv = -1; const start = j * 32; const vlen = Math.min(32, m) + start; for (let k = start; k < vlen; k++) { peq[b.charCodeAt(k)] |= 1 << k; } for (let i = 0; i < n; i++) { const eq = peq[a.charCodeAt(i)]; const pb = (phc[(i / 32) | 0] >>> i) & 1; const mb = (mhc[(i / 32) | 0] >>> i) & 1; const xv = eq | mv; const xh = ((((eq | mb) & pv) + pv) ^ pv) | eq | mb; let ph = mv | ~(xh | pv); let mh = pv & xh; if ((ph >>> 31) ^ pb) { phc[(i / 32) | 0] ^= 1 << i; } if ((mh >>> 31) ^ mb) { mhc[(i / 32) | 0] ^= 1 << i; } ph = (ph << 1) | pb; mh = (mh << 1) | mb; pv = mh | ~(xv | ph); mv = ph & xv; } for (let k = start; k < vlen; k++) { peq[b.charCodeAt(k)] = 0; } } let mv = 0; let pv = -1; const start = j * 32; const vlen = Math.min(32, m - start) + start; for (let k = start; k < vlen; k++) { peq[b.charCodeAt(k)] |= 1 << k; } let score = m; for (let i = 0; i < n; i++) { const eq = peq[a.charCodeAt(i)]; const pb = (phc[(i / 32) | 0] >>> i) & 1; const mb = (mhc[(i / 32) | 0] >>> i) & 1; const xv = eq | mv; const xh = ((((eq | mb) & pv) + pv) ^ pv) | eq | mb; let ph = mv | ~(xh | pv); let mh = pv & xh; score += (ph >>> (m - 1)) & 1; score -= (mh >>> (m - 1)) & 1; if ((ph >>> 31) ^ pb) { phc[(i / 32) | 0] ^= 1 << i; } if ((mh >>> 31) ^ mb) { mhc[(i / 32) | 0] ^= 1 << i; } ph = (ph << 1) | pb; mh = (mh << 1) | mb; pv = mh | ~(xv | ph); mv = ph & xv; } for (let k = start; k < vlen; k++) { peq[b.charCodeAt(k)] = 0; } return score; }; const distance = (a, b) => { if (a.length < b.length) { const tmp = b; b = a; a = tmp; } if (b.length === 0) { return a.length; } if (a.length <= 32) { return myers_32(a, b); } return myers_x(a, b); }; const closest = (str, arr) => { let min_distance = Infinity; let min_index = 0; for (let i = 0; i < arr.length; i++) { const dist = distance(str, arr[i]); if (dist < min_distance) { min_distance = dist; min_index = i; } } return arr[min_index]; }; export { closest, distance }; esm/mod.d.ts000066600000000301150441740370006704 0ustar00declare const distance: (a: string, b: string) => number; declare const closest: (str: string, arr: readonly string[]) => string; export { closest, distance }; //# sourceMappingURL=mod.d.ts.mapesm/mod.d.ts.map000066600000000402150441740370007462 0ustar00{"version":3,"file":"mod.d.ts","sourceRoot":"","sources":["../mod.ts"],"names":[],"mappings":"AAiHA,QAAA,MAAM,QAAQ,MAAO,MAAM,KAAK,MAAM,KAAG,MAaxC,CAAC;AAEF,QAAA,MAAM,OAAO,QAAS,MAAM,OAAO,SAAS,MAAM,EAAE,KAAG,MAWtD,CAAC;AAEF,OAAO,EAAE,OAAO,EAAE,QAAQ,EAAE,CAAC"}bench.js000066600000006166150441740370006203 0ustar00"use strict"; exports.__esModule = true; /* eslint-disable @typescript-eslint/no-var-requires */ /* eslint-disable no-console */ var Benchmark = require("benchmark"); var mod_js_1 = require("./mod.js"); var fast_levenshtein_1 = require("fast-levenshtein"); var fs = require("fs"); var jslevenshtein = require("js-levenshtein"); var leven = require("leven"); var levenshteinEditDistance = require("levenshtein-edit-distance"); var suite = new Benchmark.Suite(); var randomstring = function (length) { var result = ""; var characters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"; var charactersLength = characters.length; for (var i = 0; i < length; i++) { result += characters.charAt(Math.floor(Math.random() * charactersLength)); } return result; }; var randomstringArr = function (stringSize, arraySize) { var i = 0; var arr = []; for (i = 0; i < arraySize; i++) { arr.push(randomstring(stringSize)); } return arr; }; var arrSize = 1000; if (!fs.existsSync("data.json")) { var data_1 = [ randomstringArr(4, arrSize), randomstringArr(8, arrSize), randomstringArr(16, arrSize), randomstringArr(32, arrSize), randomstringArr(64, arrSize), randomstringArr(128, arrSize), randomstringArr(256, arrSize), randomstringArr(512, arrSize), randomstringArr(1024, arrSize), ]; fs.writeFileSync("data.json", JSON.stringify(data_1)); } var data = JSON.parse(fs.readFileSync("data.json", "utf8")); var _loop_1 = function (i) { var datapick = data[i]; if (process.argv[2] !== "no") { suite .add("".concat(i, " - js-levenshtein"), function () { for (var j = 0; j < arrSize - 1; j += 2) { jslevenshtein(datapick[j], datapick[j + 1]); } }) .add("".concat(i, " - leven"), function () { for (var j = 0; j < arrSize - 1; j += 2) { leven(datapick[j], datapick[j + 1]); } }) .add("".concat(i, " - fast-levenshtein"), function () { for (var j = 0; j < arrSize - 1; j += 2) { (0, fast_levenshtein_1.get)(datapick[j], datapick[j + 1]); } }) .add("".concat(i, " - levenshtein-edit-distance"), function () { for (var j = 0; j < arrSize - 1; j += 2) { levenshteinEditDistance(datapick[j], datapick[j + 1]); } }); } suite.add("".concat(i, " - fastest-levenshtein"), function () { for (var j = 0; j < arrSize - 1; j += 2) { (0, mod_js_1.distance)(datapick[j], datapick[j + 1]); } }); }; // BENCHMARKS for (var i = 0; i < 9; i++) { _loop_1(i); } var results = new Map(); suite .on("cycle", function (event) { console.log(String(event.target)); if (results.has(event.target.name[0])) { results.get(event.target.name[0]).push(event.target.hz); } else { results.set(event.target.name[0], [event.target.hz]); } }) .on("complete", function () { console.log(results); }) // run async .run({ async: true }); test.ts000066600000003116150441740370006105 0ustar00const { closest, distance } = require("./mod.js"); const levenshtein = (a, b) => { if (a.length === 0) { return b.length; } if (b.length === 0) { return a.length; } if (a.length > b.length) { const tmp = a; a = b; b = tmp; } const row = []; for (let i = 0; i <= a.length; i++) { row[i] = i; } for (let i = 1; i <= b.length; i++) { let prev = i; for (let j = 1; j <= a.length; j++) { let val = 0; if (b.charAt(i - 1) === a.charAt(j - 1)) { val = row[j - 1]; } else { val = Math.min(row[j - 1] + 1, prev + 1, row[j] + 1); } row[j - 1] = prev; prev = val; } row[a.length] = prev; } return row[a.length]; }; const makeid = (length) => { let result = ""; const characters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"; const charactersLength = characters.length; for (let i = 0; i < length; i++) { result += characters.charAt(Math.floor(Math.random() * charactersLength)); } return result; }; test("test compare", () => { for (let i = 0; i < 1000; i++) { const rnd_num1 = (Math.random() * 1000) | 0; const rnd_num2 = (Math.random() * 1000) | 0; const rnd_string1 = makeid(rnd_num1); const rnd_string2 = makeid(rnd_num2); const actual = distance(rnd_string1, rnd_string2); const expected = levenshtein(rnd_string1, rnd_string2); expect(actual).toBe(expected); } }); test("test find", () => { const actual = closest("fast", ["slow", "faster", "fastest"]); const expected = "faster"; expect(actual).toBe(expected); }); test.js000066600000003121150441740370006067 0ustar00var _a = require("./mod.js"), closest = _a.closest, distance = _a.distance; var levenshtein = function (a, b) { if (a.length === 0) { return b.length; } if (b.length === 0) { return a.length; } if (a.length > b.length) { var tmp = a; a = b; b = tmp; } var row = []; for (var i = 0; i <= a.length; i++) { row[i] = i; } for (var i = 1; i <= b.length; i++) { var prev = i; for (var j = 1; j <= a.length; j++) { var val = 0; if (b.charAt(i - 1) === a.charAt(j - 1)) { val = row[j - 1]; } else { val = Math.min(row[j - 1] + 1, prev + 1, row[j] + 1); } row[j - 1] = prev; prev = val; } row[a.length] = prev; } return row[a.length]; }; var makeid = function (length) { var result = ""; var characters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"; var charactersLength = characters.length; for (var i = 0; i < length; i++) { result += characters.charAt(Math.floor(Math.random() * charactersLength)); } return result; }; for (var i = 0; i < 10000; i++) { var rnd_num1 = (Math.random() * 1000) | 0; var rnd_num2 = (Math.random() * 1000) | 0; var rnd_string1 = makeid(rnd_num1); var rnd_string2 = makeid(rnd_num2); var actual = distance(rnd_string1, rnd_string2); var expected = levenshtein(rnd_string1, rnd_string2); console.log(i); if (actual !== expected) { console.log("fail"); } } .eslintrc.json000066600000001374150441740370007356 0ustar00{ "parserOptions": { "ecmaVersion": 2020 }, "extends": [ "eslint:all", "prettier", "plugin:node/recommended", "plugin:@typescript-eslint/eslint-recommended", "plugin:@typescript-eslint/recommended" ], "parser": "@typescript-eslint/parser", "plugins": ["@typescript-eslint"], "rules": { "capitalized-comments": "off", "camelcase": "off", "curly": ["error", "all"], "id-length": "off", "max-lines-per-function": "off", "max-statements": "off", "multiline-comment-style": "off", "no-bitwise": "off", "no-magic-numbers": "off", "no-param-reassign": "off", "no-plusplus": "off", "node/no-unsupported-features/es-syntax": "off", "one-var": "off", "padded-blocks": "off" } } package.json000066600000003731150441740370007047 0ustar00{ "name": "fastest-levenshtein", "version": "1.0.16", "description": "Fastest Levenshtein distance implementation in JS.", "main": "mod.js", "types": "mod.d.ts", "module": "./esm/mod.js", "repository": { "type": "git", "url": "git+https://github.com/ka-weihe/fastest-levenshtein.git" }, "keywords": [ "levenshtein", "distance", "fast", "fastest", "edit", "string", "similarity", "algorithm", "match", "comparison", "fuzzy", "search", "string", "matching", "similar", "node", "difference" ], "author": "Kasper U. Weihe", "license": "MIT", "bugs": { "url": "https://github.com/ka-weihe/fastest-levenshtein/issues" }, "homepage": "https://github.com/ka-weihe/fastest-levenshtein#README", "scripts": { "build": "tsc mod.ts --declaration", "build:esm": "tsc --declaration -p tsconfig.esm.json", "prepare": "npm run build && npm run build:esm", "bench": "npm run build && tsc bench.ts && node bench.js", "test": "npm run build && tsc test.ts && jest test.js", "test:coverage": "npm run build && jest --coverage", "test:coveralls": "npm run build && jest --coverage --coverageReporters=text-lcov | coveralls" }, "devDependencies": { "@types/benchmark": "^1.0.33", "@types/jest": "^26.0.15", "@typescript-eslint/eslint-plugin": "^4.7.0", "@typescript-eslint/parser": "^4.7.0", "benchmark": "^2.1.4", "coveralls": "^3.1.0", "eslint": "^7.13.0", "eslint-config-node": "^4.1.0", "eslint-config-prettier": "^6.15.0", "eslint-plugin-import": "^2.22.1", "eslint-plugin-node": "^11.1.0", "eslint-plugin-prettier": "^3.1.4", "fast-levenshtein": "^2.0.6", "jest": "^26.6.3", "js-levenshtein": "^1.1.6", "leven": "^3.1.0", "levenshtein-edit-distance": "^2.0.5", "natural": "^2.1.5", "prettier": "^2.1.2", "talisman": "^1.1.3", "typescript": "^4.0.5" }, "engines": { "node": ">= 4.9.1" } }