QuickJS VM

QuickJS is a small and embeddable Javascript engine. It supports most of the ES2023 specification including modules, asynchronous generators, proxies and operator overloading.

kwui is using QuickJS to define user interface structure, and responds to user input events.

Features

• Small and easily embeddable stack based VM.
• Fast interpreter with very low startup time.
• Garbage collection using reference counting.
• Small built-in standard library.
• With simplified Rust API.

Compiling JavaScript

QuickJS compiles JavaScript to VM bytecode, with 3 passes:

1. Parse JavaScript to generate initial bytecode.
2. Resolve scoped variables to local or free variable references.
3. Resolve and back patch jump offsets, peephole optimization.