516:. Unlike most other languages with exception handling, exceptions are not implicitly resignaled up the calling chain. Also unlike most other languages that provide exception handling, exceptions in CLU are considered part of ordinary execution flow and are considered a "normal" and efficient type-safe way to break out of loops or to return from functions; this allows for direct assignment of return values "except when" other conditions apply. Exceptions that are neither caught nor resignaled explicitly are immediately converted into a special failure exception that typically terminates the program.
22:
440:
A cluster is a module that encapsulates all of its components except for those explicitly named in the "is" clause. These correspond to the public components of a class in recent OO languages. A cluster also defines a type that can be named outside the cluster (in this case, "complex_number"), but
860:
The Swift language is the product of tireless effort from a team of language experts, documentation gurus, compiler optimization ninjas, and an incredibly important internal dogfooding group who provided feedback to help refine and battle-test ideas. Of course, it also greatly benefited from the
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complex_number = cluster is add, subtract, multiply, ... rep = record add = proc ... end add; subtract = proc ... end subtract; multiply = proc ... end multiply; ... end complex_number;
429:, CLU's type extension system and the root of the language's name (CLUster). Clusters correspond generally to the concept of a "class" in an OO language. For instance, here is the CLU syntax for a cluster that implements
580:
to express constraints on actual type arguments. Unlike in languages with template-based generics, a use of such a data abstraction can be type-checked without access to the implementation of the abstraction.
501:
statement. Iterators like those in CLU are now a common feature of many modern languages, such as C#, Ruby, and Python, though recently they are often referred to as generators.
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and her students starting in 1973. While it did not find extensive use, it introduced many features that are used widely now, and is seen as a step in the development of
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replace "CLU" with "Python", "record" with "instance", and "procedure" with "function or method", and you get a pretty accurate description of Python's object model.
1219:
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experiences hard-won by many other languages in the field, drawing ideas from
Objective-C, Rust, Haskell, Ruby, Python, C#, CLU, and far too many others to list.
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Matz feels that blocks are the greatest invention of Ruby (I agree.) He got the idea from a 1970s language called CLU from MIT, which called them 'iterators'...
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Cluster names are global, and no namespace mechanism was provided to group clusters or allow them to be created "locally" inside other clusters.
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s. A distinctive feature of CLU iterators is that they are implemented as coroutines, with each value being provided to the caller via a
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change between the abstract type and the representation; implicit conversions between these types are signified using the special type
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467:, and a procedure force to check that an object is a certain type. Objects may be mutable or immutable, the latter being
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129:
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1177:
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Liskov, Barbara (1992). "A history of CLU". The second ACM SIGPLAN conference on
History of programming languages.
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user-defined data abstractions. It was the first language to offer type-safe bounded parameterized types, using
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Liskov, B.; Atkinson, R.; Bloom, T.; Moss, E.; Schaffert, J.C.; Scheifler, R.; Snyder, A. (1981).
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32:
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425:, then the starting point for most new language designs. The key addition was the concept of a
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Proceedings of the third ACM SIGPLAN conference on
History of programming languages – HOPL III
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538:(multiple assignment), where more than one variable can appear on the left hand side of an
355:
124:
929:; Snyder, A.; Atkinson, R.; Schaffert, C. (August 1977). "Abstraction mechanisms in CLU".
489:(API) no matter what data they are being used with. Thus the iterator for a collection of
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Programming
Methodology Group, Computer Science and Artificial Intelligence Laboratory
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Programming
Methodology Group, Computer Science and Artificial Intelligence Laboratory
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558:. Parallel assignment (though not multiple return values) predates CLU, appearing in
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All objects in a CLU program live in the heap, and memory management is automatic.
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735:. Department of Distinctive Collections, Massachusetts Institute of Technology.
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Barron, D. W.; Buxton, J. N.; Hartley, D. F.; Nixon, E.; Strachey, C. (1963).
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787:. New York, NY, USA: Association for Computing Machinery. pp. 699–769.
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took multiple assignment and multiple returns from function calls from CLU.
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CLU's exception handling mechanisms influenced later languages like C++ and
508:, based on various attempts in other languages; exceptions are raised using
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comparison at '99 bottles of beer' multi-language demo algorithm site
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Proceedings of the ACM SIGPLAN symposium on Very high level languages
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255:
21:
622:
481:
382:
291:
1010:
888:; Zilles, Stephen (1974). "Programming with abstract data types".
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CLU is often credited as being the first language with type-safe
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610:
554:. In the same way, functions could return several values, like
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its representation type (rep) is hidden from external clients.
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1164:. Lecture Notes in Computer Science. Vol. 114. Springer.
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422:
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1085:"Functional Programming HOWTO — Python 3.8.3 documentation"
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Ierusalimschy, R.; De
Figueiredo, L. H.; Celes, W. (2007).
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s can be used interchangeably with that for an array of
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such as integers, booleans, characters and strings.
46:. Unsourced material may be challenged and removed.
737:swh:1:dir:5dc935d1c236b15a99b0750cf236b2d89ec951d0
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733:Tapes of Tech Square (ToTS) collection, MC-0741
479:Another key feature of the CLU type system are
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710:. Massachusetts Institute of Technology
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681:. Massachusetts Institute of Technology
1235:Programming languages created by women
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534:A final distinctive feature in CLU is
1230:Programming languages created in 1975
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360:Massachusetts Institute of Technology
163:Massachusetts Institute of Technology
1057:"Ruby's Roots and Matz's Leadership"
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653:statement, and multiple assignment.
397:. It is also notable for its use of
385:, multiple return values (a form of
218:Portable CLU / November 6, 2009
44:adding citations to reliable sources
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1149:Dictionary of Programming Languages
1142:: a program to compile CLU code to
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1215:Class-based programming languages
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487:application programming interface
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459:. CLU does not otherwise perform
1225:Procedural programming languages
1128:. MIT-LCS-TR-561. Archived from
1045:from the original on 2010-07-03.
542:operator. For instance, writing
20:
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1002:
969:
625:, which first appeared in CLU.
55:"CLU" programming language
31:needs additional citations for
1210:Academic programming languages
1205:Articles with example CLU code
1121:Liskov, Barbara (April 1992).
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702:Curtis, Dorothy (2009-11-06).
673:Curtis, Dorothy (2009-11-06).
1:
847:Lattner, Chris (2014-06-03).
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463:. There is a universal type
784:A History of C++: 1979--1991
593:were major inspirations for
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781:Stroustrup, Bjarne (1996).
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368:object-oriented programming
174:; 49 years ago
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978:"The main features of CPL"
849:"Chris Lattner's Homepage"
373:Key contributions include
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793:10.1145/234286.1057836
729:"CLU files, 1976–1989"
527:, before the language
220:; 14 years ago
207:; 35 years ago
1020:. pp. 2-1–2-26.
955:10.1145/359763.359789
908:10.1145/800233.807045
205:) / May 26, 1989
1162:CLU Reference Manual
1061:Appfolio Engineering
704:"Index of /pub/pclu"
421:of CLU was based on
356:programming language
40:improve this article
825:on 23 November 2019
536:parallel assignment
391:parameterized types
387:parallel assignment
375:abstract data types
169:First appeared
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1170:10.1007/BFb0035014
1123:"A History of CLU"
892:. pp. 50–59.
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556:x,y,z := f(t)
506:exception handling
504:CLU also includes
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750:Ushijima, Tetsu.
512:and handled with
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29:This article
27:
23:
18:
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1161:
1130:the original
1092:. Retrieved
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1063:. 2019-11-08
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38:Please help
33:verification
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829:21 November
407:inheritance
1199:Categories
1094:2020-05-25
1067:2019-11-15
927:Liskov, B.
855:2014-06-03
819:effbot.org
762:2016-05-26
714:2016-05-26
685:2016-05-26
657:References
540:assignment
531:had them.
469:base types
310:Influenced
225:2009-11-06
212:1989-05-26
138:procedural
66:newspapers
941:CiteSeerX
894:CiteSeerX
645:borrowed
623:iterators
598:templates
585:Influence
523:, called
482:iterators
383:iterators
362:(MIT) by
158:Developer
1188:27382594
1040:Archived
963:17343380
798:25 March
621:include
589:CLU and
413:Clusters
292:ALGOL 60
125:Paradigm
752:"clu2c"
495:integer
427:cluster
399:classes
370:(OOP).
304:Alphard
251:Website
223: (
210: (
177: (
80:scholar
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649:, the
639:Python
617:, and
615:Python
611:Sather
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514:except
510:signal
419:syntax
354:is a
340:Sather
332:Python
300:Simula
273:Major
258:.csail
245:strong
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1133:(PDF)
1126:(PDF)
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756:clu2c
651:yield
499:yield
423:ALGOL
401:with
344:Swift
320:Argus
266:.html
199:SPARC
87:JSTOR
73:books
1174:ISBN
1030:ISBN
831:2017
800:2022
643:Ruby
641:and
631:and
629:Perl
605:Java
550:and
453:down
451:and
417:The
336:Ruby
296:Lisp
264:/CLU
262:.edu
260:.mit
179:1975
172:1975
59:news
1166:doi
1154:CLU
1022:doi
990:doi
951:doi
904:doi
789:doi
633:Lua
595:C++
591:Ada
560:CPL
465:any
457:cvt
352:CLU
328:Lua
324:C++
316:Ada
256:pmg
203:VAX
119:CLU
42:by
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