Overview

This page gives a structured overview of the APL programming language.

Features

APL features [edit]
Built-ins	Primitives (functions, operators) ∙ Quad name
Array model	Shape ∙ Rank ∙ Depth ∙ Bound ∙ Index (Indexing) ∙ Axis ∙ Ravel ∙ Ravel order ∙ Element ∙ Scalar ∙ Vector ∙ Matrix ∙ Simple scalar ∙ Simple array ∙ Nested array ∙ Cell ∙ Major cell ∙ Subarray ∙ Empty array ∙ Prototype
Data types	Number (Boolean, Complex number) ∙ Character (String) ∙ Box ∙ Namespace ∙ Function array
Concepts and paradigms	Conformability (Scalar extension, Leading axis agreement) ∙ Scalar function (Pervasion) ∙ Identity element ∙ Complex floor ∙ Array ordering (Total) ∙ Tacit programming (Function composition, Close composition) ∙ Glyph ∙ Leading axis theory ∙ Major cell search ∙ First-class function
Errors	LIMIT ERROR ∙ RANK ERROR ∙ SYNTAX ERROR ∙ DOMAIN ERROR ∙ LENGTH ERROR ∙ INDEX ERROR ∙ VALUE ERROR ∙ EVOLUTION ERROR

APL syntax [edit]
General	Comparison with traditional mathematics ∙ Precedence ∙ Tacit programming (Train, Hook, Split composition)
Array	Numeric literal ∙ String ∙ Strand notation ∙ Object literal ∙ Array notation (design considerations)
Function	Argument ∙ Function valence ∙ Derived function ∙ Derived operator ∙ Niladic function ∙ Monadic function ∙ Dyadic function ∙ Ambivalent function ∙ Defined function (traditional) ∙ Dfn ∙ Function train
Operator	Operand ∙ Operator valence ∙ Tradop ∙ Dop ∙ Derived operator
Assignment	Multiple ∙ Indexed ∙ Selective ∙ Modified
Other	Function axis ∙ Bracket indexing ∙ Branch ∙ Statement separator ∙ Quad name ∙ System command ∙ User command ∙ Keyword ∙ Dot notation ∙ Function-operator overloading ∙ Control structure ∙ Comment

APL dialects [edit]
Maintained	APL+Win ∙ APL2 ∙ APL64 ∙ APL\iv ∙ Aplette ∙ April ∙ Co-dfns ∙ Dyalog APL ∙ Dyalog APL Vision ∙ dzaima/APL ∙ GNU APL ∙ Kap ∙ NARS2000 ∙ Pometo ∙ TinyAPL
Historical	A Programming Language ∙ A+ (A) ∙ APL# ∙ APL2C ∙ APL\360 ∙ APL/700 ∙ APL\1130 ∙ APL\3000 ∙ APL.68000 ∙ APL*PLUS ∙ APL.jl ∙ APL.SV ∙ APLX ∙ Extended Dyalog APL ∙ Iverson notation ∙ IVSYS/7090 ∙ NARS ∙ ngn/apl ∙ openAPL ∙ Operators and Functions ∙ PAT ∙ Rowan ∙ SAX ∙ SHARP APL ∙ Rationalized APL ∙ VisualAPL (APLNext) ∙ VS APL ∙ York APL
Derivatives	AHPL ∙ BQN ∙ CoSy ∙ ELI ∙ Glee ∙ I ∙ Ivy ∙ J ∙ Jelly ∙ K (Goal, Klong, Q) ∙ KamilaLisp ∙ Lang5 ∙ Lil ∙ Nial ∙ RAD ∙ Uiua
Overviews	Comparison of APL dialects ∙ Timeline of array languages ∙ Timeline of influential array languages ∙ Family tree of array languages

APL community [edit]
Activities	Conferences ∙ User groups and meetups ∙ Iverson Award ∙ Exercises
Chat rooms and forums	APL Farm ∙ APL Orchard ∙ APL Wiki
People	Phil Abrams ∙ Brian Becker ∙ Bob Bernecky ∙ Larry Breed ∙ Charles Brenner ∙ Jim Brown ∙ Adám Brudzewsky ∙ Gitte Christensen ∙ Peter Donnelly ∙ John Earnest ∙ Adin Falkoff ∙ Garth Foster ∙ Lib Gibson ∙ Aaron Hsu ∙ Roger Hui ∙ Ken Iverson ∙ Morten Kromberg ∙ Dick Lathwell ∙ Marshall Lochbaum ∙ Eugene McDonnell ∙ Roger Moore ∙ Trenchard More ∙ Alan Perlis ∙ Raghu Ranganathan ∙ Henry Rich ∙ Al Rose ∙ John Scholes ∙ Ian Sharp ∙ Bob Smith ∙ Geoff Streeter ∙ Joey Tuttle ∙ Arthur Whitney
Other	APL Trust ∙ APL Quote Quad ∙ Blogs ∙ Books ∙ Case studies ∙ Famous APL users ∙ Humour ∙ Jobs ∙ Merchandise ∙ Papers ∙ Podcasts ∙ TryAPL ∙ Try It Online ∙ Video channels