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The Semantics of Program Dependence
 Proceedings of the ACM SIGPLAN 89 Conference on Programming Language Design and Implementation
, 1989
"... Optimizing and parallelizing compilers for procedural languages rely on various forms of program dependence graphs (pdgs) to express the essential control and data dependences among atomic program operations. In this paper, we provide a semantic justification for this practice by deriving two differ ..."
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Optimizing and parallelizing compilers for procedural languages rely on various forms of program dependence graphs (pdgs) to express the essential control and data dependences among atomic program operations. In this paper, we provide a semantic justification for this practice by deriving two different forms of program dependence graphthe output pdg and the deforder pdgand their semantic definitions from nonstrict generalizations of the denotational semantics of the programming language. In the process, we demonstrate that both the output pdg and the deforder pdg (with minor technical modifications) are conventional dataflow programs. In addition, we show that the semantics of the deforder pdg dominates the semantics of the output pdg and that both of these semantics dominaterather than preservethe semantics of sequential execution. 1 Program Dependence Graphs Optimizing and parallelizing compilers for procedural languages rely on intermediate graph representations t...
Normal Forms and Conservative Properties for Query Languages over Collection Types
 In Proceedings of 12th ACM Symposium on Principles of Database Systems
, 1993
"... Strong normalization results are obtained for a general language for collection types. An induced normal form for sets and bags is then used to show that the class of functions whose input has height (that is, the maximal depth of nestings of sets/bags/lists in the complex object) at most i and out ..."
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Cited by 64 (30 self)
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Strong normalization results are obtained for a general language for collection types. An induced normal form for sets and bags is then used to show that the class of functions whose input has height (that is, the maximal depth of nestings of sets/bags/lists in the complex object) at most i and output has height at most o definable in a nested relational query language without powerset operator is independent of the height of intermediate expressions used. Our proof holds regardless of whether the language is used for querying sets, bags, or lists, even in the presence of variant types. Moreover, the normal forms are useful in a general approach to query optimization. Paredaens and Van Gucht proved a similar result for the special case when i = o = 1. Their result is complemented by Hull and Su who demonstrated the failure of independence when powerset operator is present and i = o = 1. The theorem of Hull and Su was generalized to all i and o by Grumbach and Vianu. Our result genera...
The rewriting logic semantics project
 University of Illinois at UrbanaChampaign
, 2005
"... Rewriting logic is a flexible and expressive logical framework that unifies algebraic denotational semantics and structural operational semantics (SOS) in a novel way, avoiding their respective limitations and allowing succinct semantic definitions. The fact that a rewrite logic theory’s axioms incl ..."
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Cited by 59 (15 self)
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Rewriting logic is a flexible and expressive logical framework that unifies algebraic denotational semantics and structural operational semantics (SOS) in a novel way, avoiding their respective limitations and allowing succinct semantic definitions. The fact that a rewrite logic theory’s axioms include both equations and rewrite rules provides a useful “abstraction dial ” to find the right balance between abstraction and computational observability in semantic definitions. Such semantic definitions are directly executable as interpreters in a rewriting logic language such as Maude, whose generic formal tools can be used to endow those interpreters with powerful program analysis capabilities. Key words: Semantics and analysis of programming languages, rewriting logic 1
Core Metamodelling semantics of UML: the pUML approach
, 1999
"... Abstract. The current UML semantics documentation has made a signi cant step towards providing a precise description of the UML. However, at present the semantic model it proposes only provides a description of the language's syntax and wellformedness rules. The meaning of the language, which ..."
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Cited by 56 (4 self)
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Abstract. The current UML semantics documentation has made a signi cant step towards providing a precise description of the UML. However, at present the semantic model it proposes only provides a description of the language's syntax and wellformedness rules. The meaning of the language, which is mainly described in English, is too informal and unstructured to provide a foundation for developing formal analysis and development techniques. Another problem is the scope of the model, which is both complex and large. This paper describes work currently being undertaken by the precise UML group (pUML), an international group of researchers and practitioners, to address these problems. A formalisation strategy is presented which concentrates on giving a precise denotational semantics to core elements of UML. This is illustrated through the development of precise de nitions of two important concepts: generalization and packages. Finally, a viewpoint architecture is proposed as a means of providing improved separation of concerns in the semantics de nition. 1
Parallel Programming using Functional Languages
, 1991
"... I am greatly indebted to Simon Peyton Jones, my supervisor, for his encouragement and technical assistance. His overwhelming enthusiasm was of great support to me. I particularly want to thank Simon and Geoff Burn for commenting on earlier drafts of this thesis. Through his excellent lecturing Cohn ..."
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Cited by 54 (3 self)
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I am greatly indebted to Simon Peyton Jones, my supervisor, for his encouragement and technical assistance. His overwhelming enthusiasm was of great support to me. I particularly want to thank Simon and Geoff Burn for commenting on earlier drafts of this thesis. Through his excellent lecturing Cohn Runciman initiated my interest in functional programming. I am grateful to Phil Trinder for his simulator, on which mine is based, and Will Partain for his help with LaTex and graphs. I would like to thank the Science and Engineering Research Council of Great Britain for their financial support. Finally, I would like to thank Michelle, whose culinary skills supported me whilst I was writingup.The Imagination the only nation worth defending a nation without alienation a nation whose flag is invisible and whose borders are forever beyond the horizon a nation whose motto is why have one or the other when you can have one the other and both
Terminological Cycles in KLONEbased Knowledge Representation Languages
, 1990
"... Cyclic definitions are often prohibited in terminological knowledge representation languages because, from a theoretical point of view, their semantics is not clear and, from a practical point of view, existing inference algorithms may go astray in the presence of cycles. In this paper, we shall con ..."
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Cyclic definitions are often prohibited in terminological knowledge representation languages because, from a theoretical point of view, their semantics is not clear and, from a practical point of view, existing inference algorithms may go astray in the presence of cycles. In this paper, we shall consider terminological cycles in a very small KLONEbased language. For this language, the effect of the three types of semantics introduced by (Nebel 1987,1989,1989a) can be completely described with the help of finite automata. These descriptions provide a rather intuitive understanding of terminologies with cyclic definitions and give insight into the essential features of the respective semantics. In addition, one obtains algorithms and complexity results for subsumption determination. As it stands, the greatest fixedpoint semantics comes off best. The characterization of this semantics is easy and has an obvious intuitive interpretation. Furthermore, important constructs such as valuerestriction with respect to the transitive or reflexivetransitive closure of a role can easily be expressed. 1.
Static and Dynamic Semantics Processing
 Proceedings of the Eighteenth Annual ACM Symposium on Principles of Programming Languages
, 1991
"... This paper presents a step forward in the use of partial evaluation for interpreting and compiling programs, as well as for automatically generating a compiler from denotational definitions of programming languages. We determine the static and dynamic semantics of a programming language, reduce the ..."
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Cited by 48 (23 self)
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This paper presents a step forward in the use of partial evaluation for interpreting and compiling programs, as well as for automatically generating a compiler from denotational definitions of programming languages. We determine the static and dynamic semantics of a programming language, reduce the expressions representing the static semantics, and generate object code by instantiating the expressions representing the dynamic semantics. By processing the static semantics of the language, programs get compiled. By processing the static semantics of the partial evaluator, compilers are generated. The correctness of a compiler is guaranteed by the correctness of both the executable specification and our partial evaluator. The results reported in this paper improve on previous work in the domain of compiler generation [16, 30], and solves several open problems in the domain of partial evaluation [15]. In essence: ffl Our compilation goes beyond a mere syntaxtosemantics mapping since the ...
VLISP: A verified implementation of Scheme
 Lisp and Symbolic Computation
, 1995
"... VLISP has produced a rigorously verified compiler from Scheme to byte codes, and a verified interpreter for the resulting byte codes. The official denotational semantics for Scheme provides the main criterion of correctness. The WandClinger technique was used to prove correctness of the main compil ..."
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Cited by 46 (3 self)
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VLISP has produced a rigorously verified compiler from Scheme to byte codes, and a verified interpreter for the resulting byte codes. The official denotational semantics for Scheme provides the main criterion of correctness. The WandClinger technique was used to prove correctness of the main compiler step. Then a state machine operational semantics is proved to be faithful to the denotational semantics. The remainder of the implementation is verified by a succession of state machine refinement proofs. These include proofs that garbage collection is a sound implementation strategy,
Bibliography: Temporal Databases
 ACM SIGMOD Record
, 1986
"... 17. COSATI CODES j18. SUBJECT TERMS (Continue an revetse If necensaiy and Identify by block number' ..."
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Cited by 45 (4 self)
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17. COSATI CODES j18. SUBJECT TERMS (Continue an revetse If necensaiy and Identify by block number'