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With this revision, occam became a language able to express useful programs, whereas occam 1 was more suited to examining algorithms and exploring the new language (however, the occam 1 compiler was written in occam 1, so there is an existence proof that reasonably sized, useful programs could be
342:
ALT count1 < 100 & c1 ? data SEQ count1 := count1 + 1 merged ! data count2 < 100 & c2 ? data SEQ count2 := count2 + 1 merged ! data status ? request SEQ out ! count1 out !
413:
language (also referred to as "occam91" during its early development) created by Geoff
Barrett at Inmos in the early 1990s. A revised Reference Manual describing occam 3 was distributed for community comment, but the language was never fully implemented in a compiler.
338:
commands. The guards are a combination of a boolean condition and an input expression, both optional. Each guard for which the condition is true and the input channel is ready is successful. One of the successful alternatives is selected for execution. Example:
346:
This will read data from channels c1 or c2 (whichever is ready) and pass it into a merged channel. If countN reaches 100, reads from the corresponding channel will be disabled. A request on the status channel is answered by outputting the counts to
246:
In the following examples indentation and formatting are critical for parsing the code: expressions are terminated by the end of the line, lists of expressions need to be on the same level of indentation. This feature, named the
379:'s work on EPL and Tony Hoare's CSP. This supported only the VAR data type, which was an integral type corresponding to the native word length of the target architecture, and arrays of only one dimension.
530:
234:, but implementations for other platforms are available. The most widely known version is occam 2; its programming manual was written by Steven Ericsson-Zenith and others at
894:
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was the last of the series of occam language developments contributed by Inmos. Defined in 1994, it was influenced by an earlier proposal for an
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introduces a list of expressions that are evaluated sequentially. This is not implicit as it is in most other programming languages. Example:
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support, functions, multi-dimensional arrays and more data types such as varying sizes of integers (INT16, INT32) and bytes.
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is the common name for the occam variant implemented by later versions of the Kent
Retargetable occam Compiler (
630:. 22nd World Occam and Transputer User Group Technical Meeting. Keele, United Kingdom: IOS Press. p. 219.
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208:
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47:
43:
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264:
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Compilers, documentation, examples, projects and utilities at the
Internet Parallel Computing Archive
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186:
182:
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51:
38:
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871:– (translator from occam to C from Kent) a Haskell-based compiler for occam and related languages.
70:
276:. Input and output cannot proceed until the other end is ready to accept or offer data. (In the
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775:
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735:
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470:(pi) to the occam name is an allusion to KRoC occam including several ideas inspired by the
198:
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444:
58:
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391:
231:
193:(CSP) process algebra, and shares many of its features. It is named after philosopher
878:
474:. It contains several significant extensions to the occam 2.1 compiler, for example:
471:
248:
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on the channel. However, the program will neither spin nor poll; thus terms like
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375:(released 1983) was a preliminary version of the language which borrowed from
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The XC programming language, which is based on occam but with C-style syntax.
323:
begins a list of expressions that may be evaluated concurrently. Example:
851:
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other independent processes from running.) Examples (c is a variable):
252:
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Information, compilers, editors and utilities at the WoTUG occam pages
110:
2.1 (official), 2.5 (unofficial), 3 (not fully implemented) / 1994
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may also convey the behaviour; also in the context that it will not
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358:
235:
220:
75:
17:
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occam 2.1 introduced several new features to occam 2, including:
461:
846:
628:
Architectures, Languages and
Techniques for Concurrent Systems
708:"occam-pi: Blending the best of CSP and the pi-calculus"
390:
is an extension produced by Inmos Ltd in 1987 that adds
833:
Egorov, A., Technical
University – Sofia, (1983–2011)
657:
Barrett, Geoff; Ericsson-Zenith, Steven (1992-03-31).
531:
List of concurrent and parallel programming languages
443:
For a full list of the changes see
Appendix P of the
772:
Communicating
Process Architectures 2005 – WoTUG-28
752:
Communicating
Process Architectures 2006 – WoTUG-29
732:
Communicating
Process Architectures 2007 – WoTUG-30
439:
Ability to return fixed-length array from function.
262:Communication between processes work through named
156:
144:
129:
103:
81:
69:
57:
37:
792:
829:. Programming Research Group, Oxford University.
561:. SGS-Thomson Microelectronics Ltd. 1995-05-12.
430:Relaxation of some of the type conversion rules
227:, as the native programming language for their
795:Transputer and Occam Research: New Directions
8:
548:
546:
268:. One process outputs data to a channel via
23:
251:, is also found in other languages such as
317:SEQ x := x + 1 y := x * x
22:
706:Barnes, Fred; Welch, Peter (2006-01-14).
624:"Occam on Field-Programmable Gate Arrays"
398:written in occam 1, despite its limits).
774:. IOS Press. 2005. pp. 405 pages.
754:. IOS Press. 2006. pp. 391 pages.
734:. IOS Press. 2007. pp. 513 pages.
622:Cook, Barry M; Peel, RMA (1999-04-11).
542:
280:case it is often said that the process
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895:Programming languages created in 1983
7:
489:Mobile channels, data, and processes
436:Channel retyping and channel arrays
421:Named data types (DATA TYPE x IS y)
272:while another one inputs data with
191:communicating sequential processes
151:Communicating sequential processes
14:
835:Записки по Компютърни архитектури
890:Procedural programming languages
885:Concurrent programming languages
597:Ericsson-Zenith, Steven (1988).
526:Concurrent programming languages
445:Inmos occam 2.1 Reference Manual
29:
464:). The addition of the symbol
223:(trademark INMOS), advised by
1:
858:Occam books on Transputer.net
827:The Laws of Occam Programming
823:Hoare, Charles Antony Richard
363:1983 "occam" by INMOS Limited
433:New operators (e.g. BYTESIN)
791:Kerridge, Jon, ed. (1993).
626:. In Cook, Barry M. (ed.).
563:Inmos document 72 occ 45 03
112:; 30 years ago
87:; 41 years ago
911:
659:"occam 3 Reference Manual"
555:occam 2.1 Reference Manual
15:
486:Run-time process creation
161:
149:
136:
125:
99:
28:
599:occam 2 Reference Manual
574:occam Programming Manual
16:Not to be confused with
576:. Prentice-Hall. 1984.
215:). It was developed by
854:(no longer maintained)
819:Roscoe, Andrew William
799:. IOS Press. pp.
687:Cite journal requires
364:
863:The occam-pi language
362:
332:specifies a list of
183:programming language
869:Tock occam compiler
82:First appeared
25:
365:
355:Language revisions
326:PAR p() q()
305:keyboard ? c
211:language (such as
189:and builds on the
781:978-1-58603-561-7
761:978-1-58603-671-3
741:978-1-58603-767-3
601:. Prentice-Hall.
195:William of Ockham
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711:. Retrieved
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680:cite journal
669:. Retrieved
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641:. Retrieved
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505:constructors
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204:occam is an
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178:
177:
499:inheritance
197:after whom
879:Categories
713:2006-11-24
671:2008-03-24
643:2016-11-28
537:References
511:rendezvous
472:π-calculus
229:transputer
225:Tony Hoare
209:procedural
206:imperative
201:is named.
187:concurrent
157:Influenced
52:concurrent
48:procedural
44:Imperative
801:253 pages
509:Extended
497:Protocol
493:Recursion
482:protocols
407:occam 2.1
402:occam 2.1
377:David May
217:David May
185:which is
71:Developer
64:David May
825:(1986).
517:See also
265:channels
242:Overview
131:Dialects
39:Paradigm
457:occam-π
451:occam-π
411:occam 3
388:occam 2
383:occam 2
373:occam 1
368:occam 1
343:count2
335:guarded
253:Haskell
138:occam-π
115: (
90: (
807:
778:
758:
738:
634:
605:
580:
503:Array
479:Nested
283:blocks
257:Python
213:Pascal
171:Python
666:Inmos
662:(PDF)
559:(PDF)
300:block
296:yield
236:Inmos
221:Inmos
181:is a
179:occam
76:Inmos
24:occam
18:OCaml
805:ISBN
776:ISBN
756:ISBN
736:ISBN
693:help
632:ISBN
603:ISBN
578:ISBN
462:KRoC
292:hang
288:wait
255:and
163:Ease
140:(pi)
117:1994
92:1983
85:1983
349:out
330:ALT
321:PAR
312:SEQ
294:or
881::
821:;
803:.
684::
682:}}
678:{{
664:.
545:^
447:.
351:.
290:,
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238:.
169:,
167:Go
165:,
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813:.
784:.
764:.
744:.
716:.
695:)
691:(
674:.
646:.
611:.
586:.
467:π
274:?
270:!
119:)
94:)
20:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
