Malte Ubl 1f28e1c3ce Skip cycle-candidate buffering for intact JSON.parse documents
Every heap dyn node carries a cycle header, so a member read of a parsed
document (parsed[i], JSON.stringify's walk) left each container it touched
in the candidate buffer and the collector traced the document over and
over. JSON.parse now tags the containers it builds with one shared region
that stays intact until the first store into any of them that could close
a cycle (a reference store; primitive and immortal stores, removals and
permutations keep it). Releases of intact containers skip buffering.

The flag is per region, not per container: a cycle can run through a
container that was never written (child.parent = root), and the last
outside reference to it may be dropped from that container. The write
barrier sits in the checked-dynamic writers (arr_push, obj_put, key_set,
define_property, reflect_define, set_prototype, symbol and named-property
tables, the reviver walk, unshift/splice/fill). A missed barrier would
leak a cycle, which the RC audit reports; walks and teardowns are
unchanged, so it cannot free live data.

Also corrects the collector header comment, which listed dyn trees as
headerless.
2026-10-16 06:12:52 -07:00
2026-10-14 17:27:02 -05:00
2026-10-16 01:29:54 -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 the types checked by the TypeScript compiler to generate machine code, and the output runs without Node.js installed. npm packages your program imports compile along with it. Code scriptc can't compile is reported at build time with a diagnostic and, where available, a rewrite hint.

scriptc is experimental and supports a subset of JavaScript, TypeScript, and Node.js APIs. Run scriptc coverage on an existing program to see how much of it compiles, and see the limitations and Node.js compatibility reference for details.

Installation

Install with Node.js 24 or later and npm:

$ npm install -g scriptc

The installed compiler runs natively on macOS, Linux, and Windows. Node.js is needed only to install it and to run WASI modules with scriptc run. Standalone compiler archives are also available from GitHub Releases.

Building executables requires a linker and the platform SDK or 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}`);

scriptc run compiles the file and runs the result:

$ scriptc run hello.ts
hello, world

scriptc build writes an executable:

$ scriptc build hello.ts -o hello >/dev/null
$ ./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 what compiles before you build. 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 >/dev/null
$ ./server
listening on http://localhost:8080

Use npm packages

npm packages compile into the executable with your code, so it doesn't 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 -o cli >/dev/null
$ ./cli
hello from scriptc

Package support is partial. See npm dependencies for which packages compile and how to check them.

Documentation

Contributing

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

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Description
GitHub Trending: vercel-labs/scriptc
Readme Apache-2.0
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TypeScript 68.1%
C 23.1%
JavaScript 8%
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