README

All your standard libraries will be assimilated into our JavaScript TypeScript collective. Resistance is futile.

Locutus is ~500 TypeScript implementations of standard library functions from PHP, Go, Python, Ruby, C, and more. Each function is individually importable and tree-shakeable.

Most of these started as rainy Sunday afternoon puzzles. Some are genuinely useful. Some are just fun to write. All of them are a way to learn how different languages solve the same problems.

Scope

Locutus ports function behavior, not foreign runtime baggage. We reimplement standard-library semantics in TypeScript, but keep API boundaries JavaScript-native.

That means we do not recreate alien language data structures or object models in Locutus APIs (for example: Go slices/maps, Python tuples/bytes, Ruby symbols, C structs/pointers, Perl refs).

Historic exception: for PHP compatibility, plain JS objects may be treated as associative arrays when locutus.objectsAsArrays is enabled.

Example: a Go date-formatting port in Locutus should accept a JavaScript Date and return a string, not a custom Go time.Time object.

Install

npm install locutus

Locutus uses pragmatic versioning: patch is the default even for function-level parity fixes; see CONTRIBUTING.md#versioning for exact bump criteria.

Use

import { sprintf } from 'locutus/php/strings/sprintf'

const effectiveness = 'futile'
console.log(sprintf('Resistance is %s', effectiveness))
// Resistance is futile

import { Contains } from 'locutus/golang/strings/Contains'

console.log(Contains('Locutus', 'cut'))
// true

Bundle Size

For bundle-sensitive browser builds, prefer per-function deep imports over category index imports.

Good:

import { sprintf } from 'locutus/php/strings/sprintf'

Avoid in browser bundles:

import { sprintf } from 'locutus/php/strings/index'

Why:

• deep imports only pull the function you asked for and its real dependencies
• category index imports can force bundlers to traverse many unrelated exports in the same namespace
• this matters most in prebundled UMD/browser artifacts where downstream tree-shaking cannot recover later

If you are publishing your own browser bundle on top of Locutus, treat deep imports as the default.

Browser Compatibility (Copy-Paste Snippets)

Code shown on function pages (Module JS / Standalone JS) targets:

• baseline widely available with downstream

Package runtime targets:

• Node: engines.node >= 22
• Published dist output (dist/ CommonJS + dist/esm ESM): ES2022

If your application targets older browsers, treat Locutus snippets like normal application code:

1. transpile to your target (for example with TypeScript, Babel, SWC, or esbuild)
2. add required polyfills for missing APIs in your environment
3. validate with your own Browserslist target and browser test matrix

Locutus does not inject polyfills into copy-paste snippets by default.

Development

Some guidelines and instructions can be found in CONTRIBUTING.md

Quick commands:

• yarn check - format + lint + test
• yarn test:parity - cross-language verification
• yarn test - full test suite
• yarn lint - Biome check
• yarn fix:biome - auto-fix

License

MIT, except for src/php/bc/ and src/php/_helpers/_bc.js which are LGPL-2.1 (derived from PHP's bcmath/Libbcmath). See LICENSE for details.