Laskin

WebAssembly build of Laskin — a reverse Polish notation calculator / programming language inspired by Forth, RPL and Plorth.

Installation

npm install laskin

Requires Node.js 22+ (or a modern browser with WebAssembly exception support).

Usage

import { createContext, LaskinError } from "laskin";

const ctx = await createContext();
ctx.run("1 2 +");
console.log(ctx.peek()); // "3"

const output = ctx.run('"hello" .');
console.log(output); // "hello\n"

try {
  ctx.run("]");
} catch (error) {
  if (error instanceof LaskinError) {
    console.error(error.type, error.message, error.line, error.column);
  }
}

API

• createContext(options?) — load the WASM module and return a context
• context.run(source) — evaluate source; returns captured output (e.g. from .)
• context.clear() / depth() / peek() / pop() / stack()
• LaskinError — thrown on interpreter errors (type, optional line/column)

File imports (import) are disabled in this build.

Options

await createContext({
  locateFile(path) {
    // Resolve laskin.wasm for bundlers / custom asset paths
    return `/assets/${path}`;
  },
});

Building from source

Requires the Emscripten SDK.

npm run build