A+ is a high-level, interactive, interpreted array programming language designed for numerically intensive applications, especially those found in financial applications.

History

In 1985, Arthur Whitney created the A programming language to replace APL. Other developers at

Morgan Stanley Morgan Stanley is an American multinational investment bank and financial services company headquartered at 1585 Broadway in Midtown Manhattan, New York City. With offices in 42 countries and more than 80,000 employees, the firm's clients in ...

extended it to A+, adding a

graphical user interface A graphical user interface, or GUI, is a form of user interface that allows user (computing), users to human–computer interaction, interact with electronic devices through Graphics, graphical icon (computing), icons and visual indicators such ...

(GUI) and other language features. The GUI A+ was released in 1988. Arthur Whitney went on to create a proprietary array language named K. Like J, K omits the APL character set. It lacks some of the perceived complexities of A+, such as the existence of statements and two different modes of

syntax In linguistics, syntax ( ) is the study of how words and morphemes combine to form larger units such as phrases and sentences. Central concerns of syntax include word order, grammatical relations, hierarchical sentence structure (constituenc ...

Features

A+ provides an extended set of functions and operators, a

with automatic synchronizing of widgets and variables, asynchronous executing of functions associated with variables and events, dynamic loading of user compiled subroutines, and other features. A+ runs on many

Unix Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...

variants, including

Linux Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

. It is

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released under a

GNU General Public License The GNU General Public Licenses (GNU GPL or simply GPL) are a series of widely used free software licenses, or ''copyleft'' licenses, that guarantee end users the freedom to run, study, share, or modify the software. The GPL was the first ...

. A newer GUI has not yet been ported to all supported platforms. The A+ language implements the following changes to the APL language: * an A+ function may have up to nine formal parameters * A+ code statements are separated by semicolons, so a single statement may be divided into two or more physical lines * The explicit result of a function or operator is the result of the last statement executed * A+ implements an object called a dependency, which is a global variable (the dependent variable) and an associated definition that is like a function with no arguments. Values can be explicitly set and referenced in exactly the same ways as for a global variable, but they can also be set through the associated definition. Interactive A+ development is primarily done in the Xemacs editor, through extensions to the editor. Because A+ code uses the original APL symbols, displaying A+ requires a font with those special characters; a font named ''kapl'' is provided on the web site for that purpose.

References

External links

*, aplusdev.org {{APL programming language APL programming language family Array programming languages Data-centric programming languages