View source for A+

{{Infobox array language
| array model              = [[flat array model|flat]] with [[box]]es
| index origin             = 0
| function styles          = [[Defined function|defined]], [[tacit]]
| numeric types            = ints, floats
| unicode support          = no
| released                 = 1988
| developer                = [[Arthur Whitney]]
| latest release version   = 4.22 (unversioned) / 2014
| implementation language  = [[wikipedia:C++|C++]]
| source                   = [https://github.com/PlanetAPL/a-plus GitHub]
| platforms                = x86, x86_64, IBM POWER, IA64, z/Architecture, 
| operating systems        = Windows, Linux, macOS, AIX, IRIX, BSD, Solaris, Tru64
| license                  = [[wikipedia:GNU_General_Public_License|GNU GPL]]
| website                  = [https://web.archive.org/web/20211202162212/http://www.aplusdev.org/index.html aplusdev.org]
| download                 = [https://web.archive.org/web/20210422094323/http://www.aplusdev.org/Download/index.html aplusdev.org/Download]
| file ext                 = .+
| documentation            = [https://github.com/PlanetAPL/a-plus/tree/master/docs GitHub]
| influenced by            = [[A]]
| influenced               = [[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 [[wikipedia:Morgan Stanley|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 ==

{|class=wikitable
! Glyph                                !! Dyadic                                        !! Monadic
|-
| <syntaxhighlight lang=apl inline>+</syntaxhighlight>   || [[Add]]                                       || [[Conjugate|Identity]]
|-
| <syntaxhighlight lang=apl inline>-</syntaxhighlight>   || [[Subtract]]                                  || [[Negate]]
|-
| <syntaxhighlight lang=apl inline>×</syntaxhighlight>   || [[Multiply]]                                  || [[Sign]]
|-
| <syntaxhighlight lang=apl inline>÷</syntaxhighlight>   || [[Divide]]                                    || [[Reciprocal]]
|-
| <syntaxhighlight lang=apl inline>*</syntaxhighlight>   || [[Power]]                                     || [[Exponential]]
|-
| <syntaxhighlight lang=apl inline>⍟</syntaxhighlight>   || [[Log]]                                       || [[Natural log]]
|-
| <syntaxhighlight lang=apl inline>|</syntaxhighlight>   || [[Residue]]                                   || [[Absolute value]]
|-
| <syntaxhighlight lang=apl inline>⊥</syntaxhighlight>   || [[Decode]]                                    || Pack
|-
| <syntaxhighlight lang=apl inline>⊤</syntaxhighlight>   || [[Encode]]                                    || Unpack
|-
| <syntaxhighlight lang=apl inline>?</syntaxhighlight>   || [[Deal]]                                      || [[Roll]]
|-
| <syntaxhighlight lang=apl inline>○</syntaxhighlight>   || [[Circle function|Circle]] (sin, cos, ...)    || [[Pi times]]
|-
| <syntaxhighlight lang=apl inline>⌹</syntaxhighlight>   || [[Solve]]                                     || [[Matrix Inverse]]
|-
| <syntaxhighlight lang=apl inline>⌈</syntaxhighlight>   || [[Max]]                                       || [[Ceiling]]
|-
| <syntaxhighlight lang=apl inline>⌊</syntaxhighlight>   || [[Min]]                                       || [[Floor]]
|-
| <syntaxhighlight lang=apl inline><</syntaxhighlight>   || [[Less than]]                                 || [[Enclose]]
|-
| <syntaxhighlight lang=apl inline>≤</syntaxhighlight>   || [[Less than or Equal to]]                     ||
|-
| <syntaxhighlight lang=apl inline>=</syntaxhighlight>   || [[Equal to]]                                  ||
|-
| <syntaxhighlight lang=apl inline>></syntaxhighlight>   || [[Greater than]]                              || [[Mix|Disclose]]
|-
| <syntaxhighlight lang=apl inline>≥</syntaxhighlight>   || [[Greater than or Equal to]]                  ||
|-
| <syntaxhighlight lang=apl inline>≠</syntaxhighlight>   || [[Not equal to]]                              ||
|-
| <syntaxhighlight lang=apl inline>⍋</syntaxhighlight>   || [[Bins]]                                      || [[Grade up]]
|-
| <syntaxhighlight lang=apl inline>⍒</syntaxhighlight>   ||                                               || [[Grade down]]
|-
| <syntaxhighlight lang=apl inline>≡</syntaxhighlight>   || [[Match]]                                     || [[Depth]]
|-
| <syntaxhighlight lang=apl inline>⍳</syntaxhighlight>   || [[Index Of|Find]]                                      || [[Interval]]
|-
| <syntaxhighlight lang=apl inline>∊</syntaxhighlight>   || [[Member]]                                    || [[Rake]] (like [[Enlist]])
|-
| <syntaxhighlight lang=apl inline>^</syntaxhighlight>   || [[And]]                                       || Stop
|-
| <syntaxhighlight lang=apl inline>∨</syntaxhighlight>   || [[Or]] or Cast                                || [[Type]]
|-
| <syntaxhighlight lang=apl inline>⍕</syntaxhighlight>   || [[Format]]                                    || [[Default Format]]
|-
| <syntaxhighlight lang=apl inline>⍎</syntaxhighlight>   || Execute in Context or Protected Execute       || [[Execute]]
|-
| <syntaxhighlight lang=apl inline>%</syntaxhighlight>   || Value in Context                              || Value (of a symbol)
|-
| <syntaxhighlight lang=apl inline>←</syntaxhighlight>   || [[Assignment]] or [[Selective Assignment]]    || Result (returns from functions)
|-
| <syntaxhighlight lang=apl inline>⊃</syntaxhighlight>   || [[Pick]]                                      || [[Raze]]
|-
| <syntaxhighlight lang=apl inline>#</syntaxhighlight>   || Choose ([[From]])                             || [[Count]]
|-
| <syntaxhighlight lang=apl inline>[;]</syntaxhighlight> ||colspan=2| [[Bracket Indexing]] (varying number of arguments)
|-
| <syntaxhighlight lang=apl inline>↑</syntaxhighlight>   || [[Take]]                                      || [[Signal]]
|-
| <syntaxhighlight lang=apl inline>↓</syntaxhighlight>   || [[Drop]]                                      || Print
|-
| <syntaxhighlight lang=apl inline>⌽</syntaxhighlight>   || [[Rotate]]                                    || [[Reverse]]
|-
| <syntaxhighlight lang=apl inline>⍉</syntaxhighlight>   || [[Dyadic transpose|Transpose Axes]]           || [[Transpose]]
|-
| <syntaxhighlight lang=apl inline>!</syntaxhighlight>   || [[Restructure]]                               || [[Item Ravel]]
|-
| <syntaxhighlight lang=apl inline>⊂</syntaxhighlight>   || Partition (a little like [[Split]])           || Partition Count
|-
| <syntaxhighlight lang=apl inline>⍴</syntaxhighlight>   || [[Reshape]]                                   || [[Shape]]
|-
| <syntaxhighlight lang=apl inline>⊣</syntaxhighlight>   || [[Left]]                                      || [[Stop|Null]] (returns <syntaxhighlight lang=apl inline>()</syntaxhighlight>)
|-
| <syntaxhighlight lang=apl inline>⊢</syntaxhighlight>   ||                                               || [[Right]]
|-
| <syntaxhighlight lang=apl inline>∪</syntaxhighlight>   || Combine Symbols                               || Separate Symbols
|-
| <syntaxhighlight lang=apl inline>,</syntaxhighlight>   || [[Catenate]]                                  || [[Ravel]]
|-
| <syntaxhighlight lang=apl inline>~</syntaxhighlight>   || [[Laminate]]                                  || [[Not]]
|-
| <syntaxhighlight lang=apl inline>/</syntaxhighlight>   || [[Replicate]]                                 || [[Reduce]] (+ × ⌈ ⌊ ∧ ∨)
|-
| <syntaxhighlight lang=apl inline>\</syntaxhighlight>   || [[Expand]]                                    || [[Scan]] (+ × ⌈ ⌊ ∧ ∨)
|-
| <syntaxhighlight lang=apl inline>.</syntaxhighlight>   || [[Inner Product]] (+.×   ⌈.+   ⌊.+)           ||
|-
| <syntaxhighlight lang=apl inline>∘.</syntaxhighlight>  || [[Outer Product]] (+ - × ÷ | ⌈ ⌊ < ≤ = ≥ > ≠) ||
|-
| <syntaxhighlight lang=apl inline>@</syntaxhighlight>   || [[Rank operator|Rank]]                        ||
|-
| <syntaxhighlight lang=apl inline>¨</syntaxhighlight>   ||                                               || [[Each]] or Apply
|-
| <syntaxhighlight lang=apl inline>⍨</syntaxhighlight>   ||                                               || Bitwise
|}

== External links ==
* [[wikipedia:A+ (programming language)|A+]]
{{APL dialects}}[[Category:APL dialects]][[Category:Flat array languages]][[Category:Languages with first-class functions]][[Category:Leading axis languages]]