A+

	Arthur Whitney
	1988
	4.22 (unversioned) / 2014
	flat with boxes
	0
	defined, tacit
	ints, floats
	no
	.+
	C++
	GitHub
	x86, x86_64, IBM POWER, IA64, z/Architecture,
	Windows, Linux, macOS, AIX, IRIX, BSD, Solaris, Tru64
	GNU GPL
	aplusdev.org
	aplusdev.org/Download
	GitHub
	A
	K, J, BQN

This page is about the Morgan Stanley dialect. For the project based on APL 90 (dialect) and presented at APL90, which replaced functions with first-class blocks, see A+ (Girardot).

A+ is an extension of the A language. A was created in 1985 by Arthur Whitney, then of Morgan Stanley. At the time, various departments had a significant investment in APL applications and talent, APL being a language well-suited to the manipulation of large arrays of numbers. As technology was moving from the mainframe to distributed systems, there was a search for a suitable APL implementation to run on SunOS, the distributed platform of the period, and this prompted Whitney to create A as a statically typed dialect of APL with various novelties like symbols as a simple scalar type and the Rank operator.

Over the course of the next few years, various extensions were made to the language, culminating in A+ in 1988, with "+" referring to the graphical user interface. While an A+ development group was formally in 1992, presented the very first version of K that very same year, and by 1994, K became the official successor of A+. In 2001, the source code was made public, and various volunteers took over development until 2008. From then until 2014 it was maintained by Robert Lefkowitz.

Primitives

Glyph	Dyadic	Monadic
<syntaxhighlight lang=apl inline>+</source>	Add	Identity
<syntaxhighlight lang=apl inline>-</source>	Subtract	Negate
<syntaxhighlight lang=apl inline>×</source>	Multiply	Sign
<syntaxhighlight lang=apl inline>÷</source>	Divide	Reciprocal
<syntaxhighlight lang=apl inline>*</source>	Power	Exponential
<syntaxhighlight lang=apl inline>⍟</source>	Log	Natural log
</source>	Residue	Absolute value
<syntaxhighlight lang=apl inline>⊥</source>	Decode	Pack
<syntaxhighlight lang=apl inline>⊤</source>	Encode	Unpack
<syntaxhighlight lang=apl inline>?</source>	Deal	Roll
<syntaxhighlight lang=apl inline>○</source>	Circle (sin, cos, ...)	Pi times
<syntaxhighlight lang=apl inline>⌹</source>	Solve	Matrix Inverse
<syntaxhighlight lang=apl inline>⌈</source>	Max	Ceiling
<syntaxhighlight lang=apl inline>⌊</source>	Min	Floor
<syntaxhighlight lang=apl inline><</source>	Less than	Enclose
<syntaxhighlight lang=apl inline>≤</source>	Less than or Equal to
<syntaxhighlight lang=apl inline>=</source>	Equal to
<syntaxhighlight lang=apl inline>></source>	Greater than	Disclose
<syntaxhighlight lang=apl inline>≥</source>	Greater than or Equal to
<syntaxhighlight lang=apl inline>≠</source>	Not equal to
<syntaxhighlight lang=apl inline>⍋</source>	Bins	Grade up
<syntaxhighlight lang=apl inline>⍒</source>		Grade down
<syntaxhighlight lang=apl inline>≡</source>	Match	Depth
<syntaxhighlight lang=apl inline>⍳</source>	Find	Interval
<syntaxhighlight lang=apl inline>∊</source>	Member	Rake (like Enlist)
<syntaxhighlight lang=apl inline>^</source>	And	Stop
<syntaxhighlight lang=apl inline>∨</source>	Or or Cast	Type
<syntaxhighlight lang=apl inline>⍕</source>	Format	Default Format
<syntaxhighlight lang=apl inline>⍎</source>	Execute in Context or Protected Execute	Execute
<syntaxhighlight lang=apl inline>%</source>	Value in Context	Value (of a symbol)
<syntaxhighlight lang=apl inline>←</source>	Assignment or Selective Assignment	Result (returns from functions)
<syntaxhighlight lang=apl inline>⊃</source>	Pick	Raze
<syntaxhighlight lang=apl inline>#</source>	Choose	Count
<syntaxhighlight lang=apl inline>[;]</source>	Bracket Indexing (varying number of arguments)
<syntaxhighlight lang=apl inline>↑</source>	Take	Signal
<syntaxhighlight lang=apl inline>↓</source>	Drop	Print
<syntaxhighlight lang=apl inline>⌽</source>	Rotate	Reverse
<syntaxhighlight lang=apl inline>⍉</source>	Transpose Axes	Transpose
<syntaxhighlight lang=apl inline>!</source>	Restructure	Item Ravel
<syntaxhighlight lang=apl inline>⊂</source>	Partition (a little like Split)	Partition Count
<syntaxhighlight lang=apl inline>⍴</source>	Reshape	Shape
<syntaxhighlight lang=apl inline>⊣</source>	Left	Null (returns <syntaxhighlight lang=apl inline>()</source>)
<syntaxhighlight lang=apl inline>⊢</source>		Right
<syntaxhighlight lang=apl inline>∪</source>	Combine Symbols	Separate Symbols
<syntaxhighlight lang=apl inline>,</source>	Catenate	Ravel
<syntaxhighlight lang=apl inline>~</source>	Laminate	Not
<syntaxhighlight lang=apl inline>/</source>	Replicate	Reduce (+ × ⌈ ⌊ ∧ ∨)
<syntaxhighlight lang=apl inline>\</source>	Expand	Scan (+ × ⌈ ⌊ ∧ ∨)
<syntaxhighlight lang=apl inline>.</source>	Inner Product (+.× ⌈.+ ⌊.+)
<syntaxhighlight lang=apl inline>∘.</source>	Outer Product (+ - × ÷ | ⌈ ⌊ < ≤ = ≥ > ≠)
<syntaxhighlight lang=apl inline>@</source>	Rank
<syntaxhighlight lang=apl inline>¨</source>		Each or Apply
<syntaxhighlight lang=apl inline>⍨</source>		Bitwise

External links

• A+