Malte Ubl 3f167db7b3 Represent nullable class and record unions as plain pointers
A union of exactly one emitted class or record arm and one unit arm
(`C | undefined`, `C | null`) now lowers to the arm pointer itself: NULL is
the unit arm and no `%ScrUnion` box is allocated. The decision lives in one
registry (nullable-unions.ts) computed from the module, so in-memory and
serialized-IR emission agree. Unions the runtime inspects as boxes (Map keys,
Set elements) keep the tagged representation.

Every structural read goes through representation-aware primitives
(union-repr.ts, unionTag/unionPeek/unionNewOwned/unitInstanceRef taking the
union id), and RC/trace dispatch resolves a nullable union to its arm's
NULL-tolerant entry points, so containers, captures, fields, params,
returns and promise payloads hold the plain pointer. Optional record fields
use a module-scope immortal sentinel for the ABSENT state. Generic helper
generators (JSON and join walkers, dyn conversions and checked casts,
live stream refs, race/generator adapters, map get widening) handle both
representations; fixed library unions assert they stay boxed. The stack-box
analyses run over the boxed union table only.

On main, the checked-extraction receivers of #781 (checked-narrows.ts)
read the tag and payload through the same representation-aware
primitives, and the stack-box and optional-array-read paths of #767 run
over the boxed union table.
2026-10-09 11:59:24 -05:00
2026-07-22 18:08:04 -05:00
2026-10-07 19:07:02 -05:00
2026-10-08 21:18:31 -05:00
2026-07-22 18:08:04 -05:00
2026-07-22 18:08:04 -05:00

scriptc

Vercel Labs Experiment npm version: scriptc License: Apache-2.0 npm downloads per month: scriptc

scriptc compiles TypeScript and JavaScript to native executables and WebAssembly. It uses TypeScript's type information to compile supported code to native instructions. Static builds run without Node.js or a JavaScript engine.

For npm dependencies and any-typed code, enable --dynamic to include the embedded quickjs-ng engine. Dependency JavaScript is included at build time.

scriptc is experimental and supports a subset of JavaScript, TypeScript, and Node.js APIs. See the limitations and Node.js compatibility reference before using it for an existing project.

Installation

Install with Node.js 24 or later and npm:

$ npm install -g scriptc

The installed compiler runs natively on supported macOS, Linux, and Windows hosts. Native compilation and execution do not require Node.js. Standalone compiler archives are also available from GitHub Releases.

Executable builds require a platform linker and SDK/sysroot. See the quickstart for prerequisites and platform support for host requirements, cross-compilation, and WebAssembly.

Build a program

Create hello.ts:

const who = process.argv.length > 2 ? process.argv[2] : "world";
console.log(`hello, ${who}`);

Compile and run it in one step:

$ scriptc run hello.ts
hello, world

Or write a standalone executable:

$ scriptc build hello.ts -o hello
$ ./hello scriptc
hello, scriptc

These examples use POSIX shell syntax. On Windows, build hello.exe and run it with .\hello.exe.

Use scriptc coverage hello.ts to check which operations compile statically, require dynamic execution, or are unsupported. See coverage reports for details.

Use Node APIs

Supported Node APIs compile to the native runtime. For example, server.ts:

import { createServer } from "node:http";

const server = createServer((req, res) => {
  res.setHeader("content-type", "application/json");
  res.end(JSON.stringify({ path: req.url }));
});

server.listen(8080, () => {
  console.log("listening on http://localhost:8080");
});
$ scriptc build server.ts -o server
$ ./server
listening on http://localhost:8080

Use npm packages

Pass --dynamic to embed an npm package's JavaScript in the executable. The result does not read node_modules at runtime.

Create cli.ts:

import pc from "picocolors";

console.log(pc.green("hello from scriptc"));
$ npm install picocolors
$ scriptc build cli.ts --dynamic -o cli
$ ./cli
hello from scriptc

Enabling --dynamic does not add support for unsupported statically typed calls. See npm dependencies for package resolution and the boundary between static and dynamic code.

Documentation

Contributing

See CONTRIBUTING.md for source setup, testing, native artifact builds, and docs development.

S
Description
GitHub Trending: vercel-labs/scriptc
Readme Apache-2.0
180 MiB
Languages
TypeScript 68%
C 23.4%
JavaScript 7.9%
C++ 0.6%