Malte Ubl 455ecc94c5 Cache constant-key reads on checked-dynamic objects per site
Every `value.name` on an any/unknown object went through the shared key
helper's kind tests, scr_dyn_obj_read, scr_dyn_obj_read_receiver and
scr_dyn_find_entry, whose one global hint table is keyed by key length and
first byte. Keys that collide there (k05/k11, or any same-length keys with
the same first letter) evicted each other and fell back to a linear scan.

A constant-key read on an ordinary object now calls scr_dyn_obj_read_ic
with a zero-initialized per-site ScrDynReadIc, thread-local wherever
program globals are. The site remembers the entry position where it last
found the key as an own data property and holds a reference to the
interned key bytes stored there. Objects that spell a key alike share
those bytes, so a hit is one pointer compare at one position; long keys
and share-table collisions compare bytes there instead. Accessors, the
builtin Object.prototype and other receiver kinds keep the previous path.
Sites release their keys with the thread's runtime state (scr_atexit),
and the RC audit lane never fills one, so its live-key count stays exact.

Sandbox, interleaved medians against the branch base: 20k parsed 12-key
records with three constant-key reads each, 300 rounds, 1.66 s -> 1.16 s;
31-json's dynamic loop variant 2.37 s -> 2.35 s (its reads are bound by
the miss on each record's entry array). Peak RSS is unchanged.
2026-10-16 10:14:11 -07:00
2026-10-16 10:33:14 -05:00
2026-10-14 17:27:02 -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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