The APLs
The BAA promotes the APLs, terse programming languages derived from Iverson’s mathematical notation.
These languages flourish where low code volume and fast development take priority. Programs are short, abstract and fast to deploy. The APLs are possibly the best languages ever devised for inquisitive computing.
The K and q languages are particularly valued in the financial markets for fast handling of very large datasets.
Some examples
A Dyalog function that returns the arithmetical mean of a list of numbers:
{(+/⍵)÷⍴⍵}
The same function as a tacit verb in J:
(+/%#)
and in NARS2000:
(+/÷⍴)
Erastosthenes’ sieve in Dyalog:
{(~⍵∊∘.×⍨⍵)/⍵}∘{1↓⍳⍵}
A K program: p is a 3 by 81 array of integers indicating the
‘exclusivity group’ for each board position; function s solves Sudoku
puzzles
p,:3/:_(p:9\:!81)%3
s:{*(,x)(,/{@[x;y;:;]'&21=x[&|/p[;y]=p]?!10}')/&~x}
Conways Game of Life
as a single expression in APL
More about the APLs…
Tutorials, cookbooks and reference
- An introduction to APL by Bernard Legrand
- The APL Wiki
- The J Wiki
- code.kx.com
- Yale Idiom List (Perlis & Rugaber, 1977)
Wikipedia articles
Community sites
