View source for SISAL

{{About||the fiber|Sisal|the town|Sisal, Yucatán|the company|Sisal (company)}}
{{Multiple issues|
{{More footnotes|date=April 2018}}
{{More citations needed|date=April 2018}}
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{{Infobox programming language
| name = SISAL
| paradigm = [[Functional programming|functional]], [[Dataflow programming|dataflow]]
| designer = James McGraw
| developer = James McGraw et al., at [[University of Manchester]], [[Lawrence Livermore National Laboratory|LLNL]], [[Colorado State University]], [[Digital Equipment Corporation|DEC]]
| released = {{Start date and age|1983}}
| typing = [[Static typing|static]], [[Strong and weak typing|strong]]
| implementations = osc, sisalc
| influenced by = VAL, [[Pascal (programming language)|Pascal]], [[C (programming language)|C]], [[Fortran]]
| influenced = [[Haskell]],{{citation needed|date=April 2016}} [[SAC programming language|SAC]]
}}
'''SISAL''' ('''Streams and Iteration in a Single Assignment Language''') is a [[General-purpose programming language|general-purpose]] [[single assignment]] [[Functional programming|functional]] [[programming language]] with [[strict semantics]], [[implicit parallelism]], and efficient [[Array (data structure)|array]] handling.

SISAL outputs a [[dataflow]] graph in Intermediary Form 1 (IF1). It was derived from the Value-oriented Algorithmic Language (VAL), designed by [[Jack Dennis]], and adds [[recursion]] and finite streams. It has a [[Pascal (programming language)|Pascal]]-like syntax and was designed to be a common [[high-level programming language]] for numerical programs on a variety of [[Multiprocessing|multiprocessor]]s.

== History ==
SISAL was defined in 1983 by James McGraw et al., at the [[University of Manchester]], [[Lawrence Livermore National Laboratory]] (LLNL), [[Colorado State University]] and [[Digital Equipment Corporation]] (DEC). It was revised in 1985, and the first [[Compiler|compiled]] [[implementation]] was made in 1986. Its performance is superior to [[C (programming language)|C]] and rivals [[Fortran]], according to some sources,<ref>Retire Fortran?: a debate rekindled, David Cann, August 1992, Communications of the ACM, Volume 35, Issue 8</ref> combined with efficient and automatic parallelization.

SISAL's name came from [[grep]]ping "sal" for "Single Assignment Language" from the Unix dictionary /usr/dict/words.

Versions exist for the [[Cray]] [[Cray X-MP|X-MP]], [[Cray Y-MP|Y-MP]], [[Cray-2|2]]; [[Sequent Computer Systems|Sequent]], [[Encore Computer|Encore Alliant]], DEC [[VAX|DEC VAX-11/784]], [[dataflow]] architectures, KSR1, [[Inmos]] [[Transputer]]s, and [[systolic array]]s.

== Architecture==

The requirements for a [[Granularity#Computing|fine-grain parallelism]] language are better met with a [[dataflow programming]] language than a [[system programming language]].{{citation needed|date=December 2016}}

SISAL is more than just a dataflow and fine-grain language. It is a set of tools that convert a textual human readable dataflow language into a graph format (named ''IF1'' - Intermediary Form 1). Part of the SISAL project also involved converting this graph format into runnable C code.<ref name="wpi2010"/>

== SISAL Renaissance Era ==
In 2010 SISAL saw a brief resurgence when a group of undergraduates at [[Worcester Polytechnic Institute]] investigated implementing a fine-grain parallelism backend for the SISAL language.<ref name="wpi2010">[http://www.wpi.edu/Pubs/E-project/Available/E-project-031210-134520/unrestricted/FinalReport.pdf Fine-Grain Parallelism: An Investigative Study into the merits of Graphical Programming and a Fine-grain Execution Mode]</ref>

In 2018 SISAL was modernized with indent-based syntax, first-class functions, lambdas, closures and lazy semantics within a project SISAL-IS.<ref name="sisalis">[https://github.com/parsifal-47/sisal-is Modernized Sisal Interpreter (MSInt)]</ref>

== References ==
===Notes===
{{Reflist}}

===Bibliography===
{{Refbegin}}
* [https://web.archive.org/web/20070920003407/http://hopl.murdoch.edu.au/showlanguage.prx?exp=876 VAL Overview]
* [http://www.cmp.uea.ac.uk/~jrwg/Sisal/00.Contents.html Sisal Language Tutorial]
{{refend}}

== External links ==
* [http://sourceforge.net/projects/sisal SISAL Parallel Programming] SourceForge.net project page

[[Category:Concurrent programming languages]]
[[Category:Functional languages]]