⍋ APL Run

A dual-dialect APL interpreter — pure Rust compiled to WebAssembly

The Interpreter

Written entirely from scratch in Rust — no dependencies on any existing APL implementation. The goals: standards-conformant, blazing fast, and fully runnable in a web browser via WebAssembly.

Supports two dialects: Dyalog APL (default) and GNU APL. Defaults: ⎕IO←1 (1-indexed arrays), ⎕DIALECT←'dyalog'. Switch to GNU APL with ⎕DIALECT←'gnu'.

Execution Pipeline

Bytecode VM — dfns compile to a tight register machine
Loop fusion — element-wise chains merged into single-pass operations
Tail-call optimization — deep recursion without stack overflow
Specialized primitives — type-specific fast paths for common operations

The AST viewer shows exactly which optimizations were applied to your code.

Technology

Rust → WebAssembly — compiled with wasm-bindgen
CodeMirror 5 — syntax-highlighted APL editing
Zero server dependency — runs entirely client-side
SIMD — WebAssembly SIMD128 auto-vectorization enabled

Contact

Jon Schuringa — [email protected]

⚠️ APL Run is under active development — not for production use.