Glossary
APL is rife with jargon. Since it is older than many of the more popular languages of today, some of the terms are quite different to those used for similar constructs in modern programming and computer science literature.
Alpha ⍺
Left argument in dfns
Argument
An array value which is passed to a function.
Array
Catenate
Join two arrays along their first axis ⍪ or last axis,.
Join two arrays along specified axes ⍪[a] ,[a].
Join two arrays by pairing cells of rank j and k: ⍪⍤j k (first axis), ,⍤j k (last axis)
Dfn
A style of function definition which encourages a functional programming style. Its left argument is referred to using ⍺ and its
Synonyms
lambda, curly brace function
Dop
First axis
The first number in the shape ⍴⍵ of an array ⍵.
First-axis functions and operators operate on or between major cells of an array.
First axis functions
First axis operators
- reduce-first
Fold
Monadic operator [reduce]
Function
Synonyms
operator (unary, binary, tertiary), procedure, subroutine
Monadic
An entity which accepts one.
A monadic function takes one argument to its right which is an array.
A monadic operator takes one operand to its left which is a function. Example: reduce /.
Synonyms
unary
Omega
Dyadic
An entity which accepts two.
A dyadic function takes two arguments, one to its left and one to its right.
Synonyms: binary
Niladic
Operator
Reduce
Monadic operator f/ (or reduice-firstf⌿)