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Can I suggest that we ignore the above exhortation and make all comments visible. There really is no good reason to hide them and it's almost impossible to recognise that we're looking at the same page after hitting the edit button. -- PhilLast 2009-07-27 07:10:49

APL is an acronym for A Programming Language - it is based on a strict (unambiguous) mathematical notation invented by the late Kenneth E Iverson; it is an interpreted, interactive, and array oriented commercial language available for all contemporary platforms. Amongst programming languages, APL has at least three unique/exclusive hallmarks:

1. It is culture 'neutral'; it uses symbols rather than 'reserved' keywords.

Really? The manuals are still available in English only. All System commands and System variables are English. All workspaces delivered by vendors are English-centric as well. I don't think it's a good idea to claim that. I cannot see a Chinaman withouth English language skills learning APL. -- KaiJaeger 2009-07-26 08:04:22

2. It is solution 'focussed'; it promotes the expression of algorithms without any consideration of machine architecture or operating system - APL is a type 'inferred' language that rarely necessitates coding structures for loops.

3. It has just one 'simple' operator precedence rule: all expressions evaluate from right to left; if necessary, this default can be overrridden by enclosing parts of an expression in round brackets, with innermost sets of brackets imposing the highest level of precedence.

APL is one of the oldest programming languages, and an important influence on the development of spreadsheets, functional programming[1], Mathematica and MatLab[2]. It is a dynamic, interpreted language based on Iverson's mathematical notation. All data are arrays. Primitive operations all extend to arrays, and are denoted by distinctive graphic symbols rather than words, making APL programs compact and visually striking, with few or no loops.

The language flourishes in scientific[3], actuarial, statistical and financial applications, and is favored by domain experts writing software for their own purposes. APL is also associated with rapid and lightweight development projects in volatile business environments.

Flourishing?! Certainly not. "APL is still used in..." or "APL is used in..." seems to me much more appropriate.

Favoured by Domain Experts?. Certainly not. There is a whole range of programming languages available which focus on that. Some of them are quite successful. Almost all of them are more successful than APL in total.

The Wikipedia article about this (see http://en.wikipedia.org/wiki/Domain_specific_language) mentions APL:

"Although notorious for its use of Greek letters and special symbols, the APL programming language, with its interactive session, provided for rapid design and deployment of interactive and scriptable domain specific languages. These usually, by design, required no special input consideration from its users such as APL keyboards or fonts."

The first sentence is gramatically incorrect. Both sentences make no sense. Worse, these sentences are located under the caption "Unix Shell Scripts". -- KaiJaeger 2009-07-26 08:04:22

Interpreters are available for a wide range of platforms including PCs, Macs, Linux, mainframes and hand-held computers. Recent notable extensions to APL interpreters and IDEs include:

• anonymous lambdas[4]

• support for class/object programming
  

• support .Net assemblies

But this is not a feature of APL as such! It is a matter of implementation. In other words, it should not be mentioned here at all.

Exactly! that's what this list is - recent extensions! Any extension must of necessity be implemented somewhere first! And it shows that APL continues to develop!

Otherwise the two things should not be summarized under one topic: OO and .NET are in this context two different things. -- KaiJaeger 2009-07-26 08:07:09

• a version of APL, Visual APL, that is a native .NET language using Visual Studio 2008 as its IDE.

• ActiveX or COM Interrop support allowing APL to use Windows resources, notably the operating system's Shell, Win32 APIs, and WMI (Windows Management Instrumentation),as well as any COM aware applications, including the MS Office suite.

• XML-array conversion primitives [5] * support for Subversion and Unicode text handling

-- StephenTaylor 2009-07-25 05:36:32

I'd just like to point out that none (not one) of the editors amending the above has seen fit to include a citation leaving the only two citations gathered so far (the main point of the excercise) sitting quietly here at the bottom with no remaining referent! -- PhilLast 2009-07-27 06:58:01

[1] http://awards.acm.org/citation.cfm?id=0703524&srt=all&aw=140&ao=AMTURING
[2] http://www.mathworks.com/company/newsletters/news_notes/clevescorner/jan06.pdf
[3] http://www.vector.org.uk/archive/v233/webber.htm
[4] insert ref to JScholes Dynamic functions paper here!
[5] insert ref to APLX & Dyalog []XML here!