Getting Started

Configuration

o- reads its engine choice from:

~/.config/o-/config.toml

Example:

[toolchain]
name = "spidermonkey"

Supported built-in engine names:

spidermonkey
v8
javascriptcore or jsc on macOS

Run a Script

From the repository root:

cargo run -- run index.js

The run command reads the file and executes it with the selected engine.

Script Example

function memoize(fn) {
  const cache = {};
  return function (n) {
    if (n in cache) return cache[n];
    cache[n] = fn(n);
    return cache[n];
  };
}

const fib = memoize(function (n) {
  return n < 2 ? n : fib(n - 1) + fib(n - 2);
});

console.log(fib(50));

CLI Shape

Current commands:

o- run <path>
o- install
o- install --global <package>
o- uninstall <package>
o- toolchain add <user> <repo>
o- toolchain remove <toolchain>

install reads the nearest project package.json. install --global installs from the npm registry into the global package root.

Toolchain Selection

The runner supports three backends:

spidermonkey
javascriptcore
v8

The selected toolchain string is passed into the core dispatcher, which maps:

javascriptcore or jsc -> JavaScriptCore
v8 -> V8
spidermonkey or empty string -> SpiderMonkey

Shared Built-ins

All engines load the shared jstd bootstrap before your script runs. That is where the common JS surface is defined.

Currently documented shared built-ins include:

console.log(...)
console.info(...)
console.warn(...)
console.error(...)
console.debug(...)
console.trace(...)
console.assert(...)
console.count(...)
console.countReset(...)
console.time(...)
console.timeLog(...)
console.timeEnd(...)
console.group(...)
console.groupCollapsed(...)
console.groupEnd()
print(...)
println(...)

Errors

Runtime errors are formatted by the shared core crate and include:

error kind
filename when available
a short source snippet
ANSI color when the terminal supports it

Color is disabled automatically when NO_COLOR is set or when TERM=dumb.

Package-manager errors use the same Report style, so install and uninstall failures print a short summary followed by concrete details such as paths, package names, and IO causes.