APL Interpreter

An implementation of APL, written in Haskell.

Supported Syntax

• All primitives, except ⌹, ⌺, and ⌸
  • Functions
    • (Monadic): ⍎⍕
    • (Dyadic): <≤≥>=⍲⍱∧∨⊤⊥∪∩⍷/⌿\⍀
    • (Ambivalent): +-×÷⍳⍴*⍟⌊⌈⊢⊣|≡≢○!?⍉⌽⊖∊⍋⍒~≠⊃⊂⊆,⍪⌷⍸↓↑
  • Operators
    • (Monadic): ⍨¨∘./⌿\⍀
    • (Dyadic): ⍤⍥∘⍣@.
• Direct Functions (dfns) (Lambda Functions)
• Direct Operators (dops) (Higher-Order Lambda Functions)
• Assignment
  • Modified Assignment (x+←1)
  • Selective Assignment (((⌽x)←y); (w x←y z); x[i;j;k]←y)
• Tacit (forks and atops)
• Axis Specification (⌽[2]x)
• Array Subscripting
• Stranding
• I/O with (⎕←) and ⍞
• Quad Names (⎕IO)
• Misc. Primitive Glyphs: ¯⍬⋄⍝

User Interface

• Configurable REPL (Haskeline)
  • Tab-Completion for Glyphs
• Pretty-Printing for Arrays (boxing) and Derived Functions (trees)
• -v option for printing syntax trees before evaluation