typescript native compiler tsn-compiler

An ahead-of-time (AOT) compiler that turns a subset of TypeScript into a standalone native executable — the way C++ or Rust do. There's no Node, V8, or JIT at runtime: the output is a self-contained binary.

.ts source ──▶ native executable

This is a learning-oriented compiler. It favors a clear, working end-to-end pipeline over feature breadth. See the language scope below for exactly what compiles.

Requirements

• macOS on Apple Silicon (arm64) — the only configuration that's tested.
• Node.js ≥ 22
• clang++ on your PATH — install the Xcode Command Line Tools if you don't have it:

  xcode-select --install

  The compiler emits C++; clang++ compiles + links it into the final binary.

Usage

Run it without installing anything via npx (use the package name, tsn-compiler):

npx tsn-compiler <file.ts> [-o <output>] [--emit-cpp]

Or install it globally — the command it installs is tsn-compiler:

npm install -g tsn-compiler
tsn-compiler <file.ts>

Options

Option	Description
-o, --output <path>	Output executable path. Defaults to the source file's basename.
--emit-cpp	Also write the generated C++ to <output>.cpp for inspection.
-h, --help	Show help.

Quick start

Create hello.ts:

console.log(20 + 22);

Compile and run it:

npx tsn-compiler hello.ts -o hello
./hello
# 42

Want to see the generated C++? Add --emit-cpp:

npx tsn-compiler hello.ts -o hello --emit-cpp
cat hello.cpp

Supported language

The goal is a small but complete pipeline. These features compile and run today:

• Types: number, boolean, string, number/string arrays (T[]), and object literals with typed fields ({ x: number; y: number }).
• console.log(...) for numbers, booleans, and strings.
• Arithmetic: + - * / % (number is IEEE double, so 5 / 2 === 2.5), unary - / +
• Comparisons & logic: < <= > >= === !== (numbers and strings), && || !
• Strings: literals, concatenation ("a" + b; numbers coerce, e.g. "n=" + 5), lexicographic comparison, s.length, indexing s[i], and methods substring / slice / indexOf / charAt / charCodeAt / toUpperCase / toLowerCase
• Variables: let / const (the type is inferred when you omit the annotation; var is not supported), assignment (x = e, a[i] = e, obj.f = e, +=, i++)
• Control flow: if / else, while, for
• Functions: top-level, typed params + return type, return, and calls (recursion works)
• Arrays: literals (incl. empty []), indexing (xs[i], computed indices), .length, .push(v)
• Objects: literals and field access (p.x)

function square(n: number): number {
  return n * n;
}
function sumOfSquares(a: number, b: number): number {
  return square(a) + square(b);
}
console.log(sumOfSquares(3, 4)); // 25

let xs: number[] = [10, 20, 30];
console.log(xs[0]); // 10
console.log(xs.length); // 3

let p: { x: number; y: number } = { x: 3, y: 4 };
console.log(p.x + p.y); // 7

let name = "Ada Lovelace";
console.log(name.length); // 12
console.log(name.toUpperCase()); // ADA LOVELACE
console.log(name.slice(0, 3)); // Ada
console.log("apple" < "banana"); // 1  (lexicographic; booleans print as 1/0)

console.log currently takes exactly one argument. A let/const without a type annotation infers its type from the initializer — an integer literal like const a = 12 compiles to int a = 12, a decimal to double, and so on.

Notes & limitations

• number is an IEEE double (printed JS-style, shortest round-trip) — e.g. 20 / 6 prints 3.3333333333333335. Functions and object fields still accept scalars only (number/boolean/string) — arrays/objects can't be passed or returned yet.
• var is not supported (and never will be) — use let or const.
• Out of scope for now: null/undefined, classes, closures, exceptions, async, modules, generics, union/any types, and garbage collection.
• Target is macOS arm64 only. Other platforms aren't supported yet.

How it works

The compiler runs four stages (see src/):

1. Parse — the official typescript package parses your source into a TypeScript AST.
2. Lower — that AST is lowered into a small, typed internal IR (src/ir/nodes.ts).
3. Codegen — the IR is emitted as C++ source (src/codegen/emit.ts).
4. Build — clang++ compiles + links the .cpp into a native executable (src/backend/clang.ts).

Development

git clone https://github.com/fardad-dev/typescript-native.git
cd typescript-native
npm install          # also builds dist/ via the prepare script

npm run build        # compile the compiler (tsc -> dist/)
npm test             # compile each tests/cases/*.ts, run it, diff against *.expected

# run the local build directly without a global install
node dist/index.js examples/test1.ts -o out --emit-cpp && ./out

Each language feature has a tests/cases/<name>.ts input paired with a <name>.expected stdout file; tests/e2e.test.ts compiles, runs, and diffs them.

License

MIT — see LICENSE.