APL syntax

APL's core syntactic principles are:

• Arrays as first class citizens
• Functions take arrays as input and produce arrays as output
• Operators take functions as operands and produce derived functions

Example array definitions

      simplenumvec←1 2 3 4 ⍝ A simple numeric vector
      simplecharvec←'ABCD' ⍝ A simple character vector

Example function definition

    ∇  r←l Tradfn r              
[1]    ⍝ An infix (dyadic) tradfn
[2]    r←l r                     
    ∇  

Works in: Dyalog APL, APL2, GNU APL, NARS2000

Example operator definition

     ∇ r←larg(Main OVER PreProc)rarg                                                 
[1]    r←(PreProc larg)Main(PreProc rarg)                                            
     ∇