apiel

A subset of the APL programming language implemented in Rust. Evaluate APL expressions from Rust code through the apl! macro.

Usage

use apiel::apl;

// Evaluate APL expressions
let sum = apl!("+/ ⍳ 10").unwrap();           // [55.0]
let mat = apl!("⍴ 2 3 ⍴ ⍳ 6").unwrap();      // [2.0, 3.0]
let fib = apl!("{⍵<2: ⍵ ⋄ (∇ ⍵-1)+∇ ⍵-2} 10").unwrap();  // [55.0]

// Pass Rust data as ⍵ (right argument)
let result = apl!("+/ ⍵", omega: &[1.0, 2.0, 3.0, 4.0, 5.0]).unwrap();  // [15.0]

// Pass both ⍺ (left) and ⍵ (right)
let result = apl!("⍺ × ⍵", alpha: &[10.0], omega: &[1.0, 2.0, 3.0]).unwrap();  // [10.0, 20.0, 30.0]

// Shared environment -- variables persist across calls
let mut env = apiel::Env::new();
apl!("data←⍳ 10", &mut env).unwrap();
apl!("total←+/ data", &mut env).unwrap();
let result = apl!("total", &mut env).unwrap();  // [55.0]

// Define and call named functions
apl!("double←{⍵×2}", &mut env).unwrap();
apl!("double 1 2 3", &mut env).unwrap();  // [2.0, 4.0, 6.0]

What's Supported

• Arithmetic: + - × ÷ * ⍟ ○ ! ? | ⌈ ⌊ ⌹
• Arrays: ⍴ , ⌽ ⍉ ↑ ↓ ⍋ ⍒ ⊂ ⊃ ⊆ ⌷ ∪ ∩ ~ ⊣ ⊢ ≡ ≢ ⍷
• Comparison: = ≠ < > ≤ ≥ ∧ ∨ ⍲ ⍱
• Operators: f/ reduce, f\ scan, ∘.f outer product, f.g inner product, f¨ each, f⍨ commute, f⍣n power, {f}∘{g} compose, {f}⍥{g} over, {f}⍤k rank, {f}@i at, {f}⌸ key
• Trains: (f g h) fork, (f g) atop -- supports primitives, reductions, and named functions
• Language: ← assignment, x+←1 modified assignment, x[i]←v indexed assignment, {⍵} dfns, ∇ recursion, ⋄ : guards, ¯ high minus, '...' strings, ⊥ ⊤ encode/decode, nested arrays

Affiliation

Capstone project for the rustcamp by the Ukrainian Rust Community.