Engine Backends

Overview

o- can run JavaScript on multiple engine backends behind the same JSEngine interface.

SpiderMonkey

Path:

toolchains/spidermonkey

Notes:

• Loads the shared jstd bootstrap before running user code.
• Uses a dedicated SpiderMonkey runtime wrapper.
• Runtime teardown is currently treated conservatively to avoid shutdown-time crashes in this embedding.

JavaScriptCore

Path:

toolchains/javascriptcore

Notes:

• Uses rust_jsc.
• Registers shared host callbacks and then evaluates the same jstd bootstrap used by the other engines.

V8

Path:

toolchains/v8

Notes:

• Uses the Rust v8 bindings.
• Initializes the V8 platform once, then creates a fresh isolate/context for each run.
• Installs the same __jstd_* host callbacks and executes the shared bootstrap before evaluating your script.

Shared Contract

All engines are expected to:

1. implement the shared JSEngine trait from o-core
2. return the shared JSError / JSResult types
3. expose the jstd host hooks needed by the bootstrap script
4. make common built-ins behave the same way where possible