Tish is a TypeScript- and JavaScript-compatible language implemented in Rust. It is aimed at teams who want a familiar surface syntax, predictable semantics, and the option to ship either interpreted scripts or runtime free native binaries.
The same source can run on a tree-walking interpreter, a bytecode VM, or compiled targets (native, WASM/WASI, and others). Network, filesystem, and process APIs are feature-gated so defaults stay safe. For the full syntax and semantics, see the canonical spec in-repo; for tutorials and reference, see tishlang.com/docs.
- JS-like surface —
let/const,fn, arrows, template literals, async/await, modules, and a large slice of familiar builtins (console,Math,JSON, arrays, strings, objects). - Two ways to run — interpret for fast iteration (
tish run, REPL); compile to native or WASM for distribution and performance (tish build). - Memory-safe implementation — Rust-hosted runtime and compiler pipeline; no GC in the host language for the toolchain itself.
- Secure by default — I/O and platform APIs (
http,fs,process, etc.) are opt-in via features. - No
undefined—nullonly where JS would use undefined; strict equality (===/!==) without loose coercion. - Optional types — TypeScript-style annotations are parsed for tooling and future checking; see the language reference for status.
Full specification: docs/LANGUAGE.md. Implementation status, gaps, and JS compatibility: docs/plan-gap-analysis.md.
User-facing guides and reference:
| Section | Description |
|---|---|
| Getting started | Install Tish, build your first app |
| First app | Run and build workflows, targets |
| Editor & IDE | VS Code, LSP, tasks, Neovim |
| Language server | tish-lsp capabilities |
| Formatting | tish-fmt |
| Linting | tish-lint |
| Interactive REPL | Multi-line input, completion, history |
| Language overview | Syntax, keywords, semantics |
| Tish vs JavaScript | Differences and additions from JS |
| Builtins | Console, Math, JSON, Array, String, Object |
| Features (APIs) | http, fs, process, regex — feature-gated |
| Native backend | Rust, Cranelift, LLVM compilation |
| WASM targets | Web and WASI |
| Deploy | Platform and hosting |
Contributor- and spec-oriented material in docs/:
| File | Purpose |
|---|---|
| LANGUAGE.md | Canonical language reference (syntax, semantics, builtins) |
| ecma-alignment.md | ECMA-262 / test262 mapping |
| plan-gap-analysis.md | Implementation audit, MVP checklist |
| architecture-next-steps.md | Crate layout, design decisions |
| builtins-gap-analysis.md | Builtins across Rust vs bytecode VM (Cranelift/WASI) |
| Tool | Purpose |
|---|---|
tish |
CLI — run, repl, build, dump-ast |
tish-fmt |
Formatter |
tish-lint |
Linter (--format sarif for code scanning) |
tish-lsp |
Language server; uses tish_fmt / tish_lint as libraries |
tish-security/ (sibling repo) |
Rules & CI examples — clone next to tish/ as ../tish-security (OpenGrep, ast-grep, Comby, Codacy scaffold, fixtures) |
tree-sitter-tish/ |
Tree-sitter grammar (editors, ast-grep, future OpenGrep integration) |
| VS Code extension | tish-vscode — grammar, snippets, LSP client, tasks |
Related docs on tishlang.com: Editor & IDE, Language server, Formatting, Linting.
Install globally:
brew tap tishlang/tish https://github.com/tishlang/tish
brew install tishOr locally with npm:
npm install @tishlang/tishMore options: Installation.
npx @tishlang/create-tish-app my-app
cd my-app
npx @tishlang/tish run src/main.tish// hello.tish
fn greeting(name) = `Hello, ${name}!`
console.log(greeting("World"))
tish run hello.tish
# Hello, World!
tish build hello.tish -o hello
./hello
# Hello, World!Native binaries are standalone (no Tish or Rust runtime required on the machine that runs them). Backends, flags, and WASM are covered in First app, Native backend, and WASM targets.
Contributions are welcome. See CONTRIBUTING.md for building, testing, and code style. Tish is licensed under the Pay It Forward License (PIF).
JavaScript equivalents live in tests/core/*.js. Compare Tish with Node.js or Bun:
./scripts/run_performance_manual.shDetails: docs/perf.md.
Tish is licensed under the Pay It Forward License (PIF). See LICENSE.