IMP (programming language): Difference between revisions

Revision as of 06:05, 18 May 2012

Revision as of 08:15, 25 May 2012

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'''IMP''' was a [[systems (programming)|systems]] [[programming language]] developed by [[NedE. T. Irons]] in the late 1960s through early 1970s. Unlike most other systems programming languages, IMP was an [[:Category:Extensible syntax programming languages|extensible syntax programming language]].

Even though its designer refers to the language as "being based on [[ALGOL]]", IMP excludes many ''defining'' features of that language, while supporting a very non-ALGOL-like one: syntax extensibility.

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A compiler for IMP existed as early as 1965 and was used for programming the [[CDC 6600]] time-sharing system, which was in use at the [[Institute for Defense Analyses]] since 1967. Although the compiler is slower than comparable ones for non-extensible languages, it has been used for practical production work.

IMP compilers were developed for the [[CDC-6600]], [[Cray]], [[PDP-10]] and [[PDP-11]] computers. Important IMP versions were '''IMP65''', '''IMP70''', and '''IMP72'''.

IMP is unrelated to the [[Edinburgh IMP programming language]].

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<ATOM> ::= ABS ( <ATOM,A> ) ::= DEWOP(214B,AREG1(1,13),A)

The semantic part of this statement consists of a call on the semantic routine <code>DEWOP</code>. The arguments are the octal constant <code>214B</code>, the semantic routine call <code>AREG1(1,13)</code>, and <code>A</code>, which is the object on top of the stack at the moment this production is invoked. <code>DEWOP</code> is a semantic routine which respectively takes as its arguments a PDP-10 machine language [[opcode]], a register object, and any other object, and produces an object whose value is the result of executing the designated machine instruction using as address field the object which is its last argument. In this specific example, the opcode <code>214B</code> designates the <code>Load Magnitude</code> instruction, and thus the result of the above syntax statement will be to compile code to compute the absolute value of <code>A</code>.

==Folklore Operating System==

IMP was the language used on [[NSA]]'s homegrown [[time-sharing]] system known as '''Folklore'''.

<ref>{{cite web|last=Cotter|first=George|title=High-Performance Computing at the National Security Agency|url=http://publishing.cdlib.org/ucpressebooks/view?docId=ft0f59n73z&chunk.id=d0e12339&toc.depth=1&toc.id=d0e12308&brand=ucpress|work=Frontiers of Supercomputing II|publisher=UNIVERSITY OF CALIFORNIA PRESS|accessdate=25 May 2012}}</ref>

==See also==

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==References==

{{Reflist}}

* ''Experience with an Extensible Language'', Irons E.T., '''CACM''', Vol. 13, No. 1, January 1970.

* ''Syntax Extension and the IMP72 Programming Language'', Walter Bilofsky, Yale University, '''SIGPLAN Notices''', May 1974.