Language overview

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

Development

APL development [edit]
Interface	Session ∙ Typing glyphs ∙ Fonts ∙ Text editors
Publications	Introductions ∙ Learning resources ∙ Simple examples ∙ Advanced examples ∙ Mnemonics ∙ Standards ∙ A Dictionary of APL ∙ Case studies ∙ Documentation suites ∙ Books ∙ Papers ∙ Videos ∙ Periodicals
Current developers	APLNow ∙ Dyalog ∙ GNU APL community ∙ IBM ∙ Sudley Place
Historical developers	Burroughs ∙ CDC ∙ DEC ∙ Data General ∙ HP ∙ Harris ∙ IPSA ∙ MicroAPL ∙ STSC ∙ Siemens ∙ Xerox

APL features [edit]
Built-ins	Primitive function ∙ Primitive operator ∙ Quad name
Array model	Shape ∙ Rank ∙ Depth ∙ Bound ∙ Index ∙ Axis ∙ Ravel ∙ Ravel order ∙ Element ∙ Scalar ∙ Vector ∙ Matrix ∙ Simple scalar ∙ Simple array ∙ Nested array ∙ Box ∙ Cell ∙ Major cell ∙ Subarray ∙ Empty array ∙ Prototype
Concepts and paradigms	Leading axis theory ∙ Scalar extension ∙ Conformability ∙ Scalar function ∙ Glyph ∙ Identity element ∙ Total array ordering
Errors	LIMIT ERROR ∙ RANK ERROR ∙ SYNTAX ERROR

APL syntax [edit]
General	Comparison with traditional mathematics ∙ Precedence ∙ Tacit programming
Array	Numeric literal ∙ String ∙ Strand notation ∙ Object literal ∙ Array notation
Function	Argument ∙ Function valence ∙ Derived function ∙ Niladic function ∙ Monadic function ∙ Dyadic function ∙ Ambivalent function ∙ Tradfn ∙ Dfn ∙ Derived function ∙ Function train
Operator	Operand ∙ Operator valence ∙ Tradop ∙ Dop ∙ Derived operator
Assignment	Multiple ∙ Indexed ∙ Selective ∙ Modified
Other	Function axis ∙ Branching ∙ System command ∙ User command ∙ Keyword ∙ Dot notation

APL dialects [edit]
Maintained	APL+Win (APL*PLUS) ∙ APL2 ∙ APL64 ∙ APL\iv ∙ Co-dfns ∙ Dyalog APL ∙ dzaima/APL ∙ GNU APL ∙ NARS2000 ∙ ngn/apl
Historical	Iverson notation ∙ A Programming Language ∙ A+ (A) ∙ APL# ∙ APL.68000 ∙ APL.SV ∙ APLX ∙ APL\1130 ∙ APL\360 ∙ NARS ∙ openAPL ∙ Rowan ∙ SHARP APL (SAX) ∙ VisualAPL (APLNext) ∙ VSAPL ∙ York APL
Derivatives	ELI ∙ J ∙ K (Q, KDB+) ∙ LYaPAS ∙ Nial ∙ RAD ∙ AHPL

APL community [edit]
Sharing code	APLcart ∙ APLTree
User groups	APL Borealis (Canada) ∙ APL et J (France) ∙ APL-Germany ∙ BAA (UK) ∙ FinnAPL (Finland) ∙ JAPLA (Japan) ∙ SAUG (Switzerland) ∙ SIGAPL (USA) ∙ SwedAPL (Sweden)
People	Phil Abrams ∙ Bob Bernecky ∙ Larry Breed ∙ Charles Brenner ∙ Jim Brown ∙ Gitte Christensen ∙ Philip Van Cleave ∙ Peter Donnelly ∙ Dan Dyer ∙ Adin Falkoff ∙ Garth Foster ∙ Roger Hui ∙ Ken Iverson ∙ Morten Kromberg ∙ Marshall Lochbaum ∙ Eugene McDonnell ∙ John McPherson ∙ Jon McGrew ∙ Donald McIntyre ∙ Roger Moore ∙ Alex Morrow ∙ Alan Perlis ∙ Al Rose ∙ William Rutiser ∙ John Scholes ∙ Ian Sharp ∙ Lynne Shaw ∙ Bob Smith ∙ Roy Sykes ∙ Raymond Tisserand ∙ Arthur Whitney ∙ Clark Wiedmann
Other	APL Orchard ∙ APL Wiki ∙ Dyalog user meetings ∙ Dyalog webinars ∙ Iverson Award ∙ Conferences ∙ Blogs ∙ Forums ∙ Code golf ∙ APL Quote Quad

APL built-ins [edit]
Primitive functions
	Scalar
		Monadic	Conjugate ∙ Negate ∙ Signum ∙ Not ∙ Roll ∙ Type
		Dyadic	Add ∙ Subtract ∙ Equal to (Xnor) ∙ Not Equal to (Xor) ∙ Minimum ∙ Maximum ∙ Comparison functions
	Non-Scalar
		Structural	Shape ∙ Reshape ∙ Tally ∙ Depth ∙ Ravel ∙ Reverse ∙ Raze ∙ Mix ∙ Cut (K) ∙ Pair ∙ Replicate ∙ Partitioned Enclose
		Selection	Take ∙ Drop ∙ Unique ∙ Identity ∙ Select
		Selector	Interval Index ∙ Indices
		Computational	Match ∙ Not Match ∙ Nub Sieve ∙ Format ∙ Execute
Primitive operators		Each ∙ Reverse Compose ∙ Replicate
Quad names
	Arrays	Index origin ∙ Migration level
	Functions
	Operators
Other	Zilde ∙ High minus ∙ Function axis