## Process Semantics of Graph Reduction (1995)

Venue: | Proc. CONCUR '95, volume 962 of Lecture Notes in Computer Science |

Citations: | 6 - 1 self |

### BibTeX

@INPROCEEDINGS{Brock95processsemantics,

author = {Simon Brock and Gerald Ostheimer and North Haugh and Fife Ky Ss},

title = {Process Semantics of Graph Reduction},

booktitle = {Proc. CONCUR '95, volume 962 of Lecture Notes in Computer Science},

year = {1995},

pages = {471--485},

publisher = {Springer-Verlag}

}

### Years of Citing Articles

### OpenURL

### Abstract

This paper introduces an operational semantics for call-by-need reduction in terms of Milner's ß-calculus. The functional programming interest lies in the use of ß-calculus as an abstract yet realistic target language. The practical value of the encoding is demonstrated with an outline for a parallel code generator. From a theoretical perspective, the ß-calculus representation of computational strategies with shared reductions is novel and solves a problem posed by Milner [13]. The compactness of the process calculus presentation makes it interesting as an alternative definition of call-by-need. Correctness of the encoding is proved with respect to the call-by-need -calculus of Ariola et al. [3]. 1 Introduction Graph reduction of extended -calculi has become a mature field of applied research. The efficiency of the implementations is due in great measure to a technique known as `sharing', whereby argument values are computed (at most) once and then memoized for future reference. Both...

### Citations

997 | Active Messages: a Mechanism for Integrated Communication and Computation
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- 1993
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Citation Context ... Leftmost reduction in this calculus essentially models callby -need, although that fact is not established in the paper. Launchbury presents an operational semantics for graph reduction of -terms in =-=[11]-=- with a much simpler set of reduction axioms, albeit at the expense of introducing into these axioms an additional layer of global environments which are not part of the source language. Ariola et al.... |

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Citation Context ...erm `call-by-need' for the parameter passing mechanism. Modern practice is not to perform reduction inside -abstractions, i.e., to stop reduction at weak head normal forms, as pointed out by Abramsky =-=[2]-=-, who studies the semantics of the resulting `lazy' -calculus. Despite the maturity of the applications based on Wadsworth's ideas, the underlying theory of -calculi with shared reductions is currentl... |

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Optimal reduction in weak lambda-calculus with shared environments
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GRIP -- a high-performance architecture for parallel graph reduction
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Citation Context ... terms can be related back to the originals via a simple function that erases the annotations. These states can also be found in some implementations of functional languages, such as the GRIP machine =-=[17]-=-. The initial creation of a let becomes (x:M)N ! let S x = N in M where the subscript implies the evaluation of N is suspended. Subsequently when M needs x then the reduction let S x = N in E[x] ! let... |

7 |
Semantics and Pragmatics of the -Calculus
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Citation Context ...chnique known as `sharing', whereby argument values are computed (at most) once and then memoized for future reference. Both the term `graph reduction' and the original algorithm are due to Wadsworth =-=[20]-=- who also coined the term `call-by-need' for the parameter passing mechanism. Modern practice is not to perform reduction inside -abstractions, i.e., to stop reduction at weak head normal forms, as po... |

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J.-J.Levy. Explicit substitutions
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- 1991
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Citation Context .... In particular, since the ��-calculus only requires the communication of atomic names, rather than of arbitrarily complex terms, our solution makes substitution explicit in the sense of Abadi et =-=al. [1]. Ye-=-t the encoding of Figure 3 is arguably as concise as any specification of call-by-need that we have seen. 5 Implementing the ��-calculus While the reader may agree at this point that the encoding ... |

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Citation Context ...more natural model would be to implement sharing. One of the aims of the work presented here was to solve this problem. We go further than Milner by relating the encodings to implementations. Glauert =-=[6, 7]-=- describes compatible encodings of lazy and eager evaluation in an asynchronous process notation. It is shown the process notation used can be translated into a graph reduction language. In Ostheimer ... |

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Citation Context ...sistent handlers and composite handlers. Then a simple induction on the structure of the encoding 2 This is very similar to the programming model for the STAR:DUST architecture described in Ostheimer =-=[15]-=- shows that we map -terms to actions---a message action in the case of encoding a variable and allocation actions in the encodings of -abstraction and application. Further useful properties of the enc... |

2 |
A call-by-need -calculus
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Citation Context ... the process calculus presentation makes it interesting as an alternative definition of call-by-need. Correctness of the encoding is proved with respect to the call-by-need -calculus of Ariola et al. =-=[3]-=-. 1 Introduction Graph reduction of extended -calculi has become a mature field of applied research. The efficiency of the implementations is due in great measure to a technique known as `sharing', wh... |

2 |
Asynchronous mobile processes
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Citation Context ...more natural model would be to implement sharing. One of the aims of the work presented here was to solve this problem. We go further than Milner by relating the encodings to implementations. Glauert =-=[6, 7]-=- describes compatible encodings of lazy and eager evaluation in an asynchronous process notation. It is shown the process notation used can be translated into a graph reduction language. In Ostheimer ... |

2 |
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Citation Context ... compatible encodings of lazy and eager evaluation in an asynchronous process notation. It is shown the process notation used can be translated into a graph reduction language. In Ostheimer and Davie =-=[16], an-=- encoding for shared reduction strategies was given in the (synchronous) monadic ��-calculus but the correspondence to -terms was not formalized. Boudol [4] encodes a version of -calculus with exp... |