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Compilation and Equivalence of Imperative Objects
, 1998
"... We adopt the untyped imperative object calculus of Abadi and Cardelli as a minimal setting in which to study problems of compilation and program equivalence that arise when compiling objectoriented languages. We present both a bigstep and a smallstep substitutionbased operational semantics fo ..."
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Cited by 34 (4 self)
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We adopt the untyped imperative object calculus of Abadi and Cardelli as a minimal setting in which to study problems of compilation and program equivalence that arise when compiling objectoriented languages. We present both a bigstep and a smallstep substitutionbased operational semantics for the calculus. Our rst two results are theorems asserting the equivalence of our substitutionbased semantics with a closurebased semantics like that given by Abadi and Cardelli. Our third result is a direct proof of the correctness of compilation to a stackbased abstract machine via a smallstep decompilation algorithm. Our fourth result is that contextual equivalence of objects coincides with a form of Mason and Talcott's CIU equivalence; the latter provides a tractable means of establishing operational equivalences. Finally, we prove correct an algorithm, used in our prototype compiler, for statically resolving method osets. This is the rst study of correctness of an objectoriented abstract machine, and of operational equivalence for the imperative object calculus.
Compilation by Transformation in NonStrict Functional Languages
, 1995
"... In this thesis we present and analyse a set of automatic sourcetosource program transformations that are suitable for incorporation in optimising compilers for lazy functional languages. These transformations improve the quality of code in many different respects, such as execution time and memory ..."
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Cited by 32 (1 self)
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In this thesis we present and analyse a set of automatic sourcetosource program transformations that are suitable for incorporation in optimising compilers for lazy functional languages. These transformations improve the quality of code in many different respects, such as execution time and memory usage. The transformations presented are divided in two sets: global transformations, which are performed once (or sometimes twice) during the compilation process; and a set of local transformations, which are performed before and after each of the global transformations, so that they can simplify the code before applying the global transformations and also take advantage of them afterwards. Many of the local transformations are simple, well known, and do not have major effects on their own. They become important as they interact with each other and with global transformations, sometimes in nonobvious ways. We present how and why they improve the code, and perform extensive experiments wit...
Relational Reasoning about Functions and Nondeterminism
, 1998
"... Reproduction of all or part of this work is permitted for educational or research use on condition that this copyright notice is included in any copy. See back inner page for a list of recent BRICS Dissertation Series publications. Copies may be obtained by contacting: BRICS ..."
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Cited by 31 (4 self)
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Reproduction of all or part of this work is permitted for educational or research use on condition that this copyright notice is included in any copy. See back inner page for a list of recent BRICS Dissertation Series publications. Copies may be obtained by contacting: BRICS
A Statically Allocated Parallel Functional Language
 In Proceedings of the International Conference on Automata, Languages and Programming (2000
, 2000
"... We describe SAFL, a callbyvalue firstorder functional language which is syntactically restricted so that storage may be statically allocated to fixed locations. Evaluation of independent subexpressions happens in parallel  we use locking techniques to protect shareduse function definitions (i. ..."
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Cited by 31 (11 self)
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We describe SAFL, a callbyvalue firstorder functional language which is syntactically restricted so that storage may be statically allocated to fixed locations. Evaluation of independent subexpressions happens in parallel  we use locking techniques to protect shareduse function definitions (i.e. to prevent unrestricted parallel accesses to their storage locations for argument and return values). SAFL programs have a well defined notion of total (program and data) size which we refer to as `area'; similarly we can talk about execution `time'. Fold/unfold transformations on SAFL provide mappings between different points on the areatime spectrum. The space of functions expressible in SAFL is incomparable with the space of primitive recursive functions, in particular interpreters are expressible. The motivation behind SAFL is hardware description and synthesiswe have built an optimising compiler for translating SAFL to silicon.
Semantic Foundations for Embedding HOL in Nuprl
 ALGEBRAIC METHODOLOGY AND SOFTWARE TECHNOLOGY
, 1996
"... We give a new semantics for Nuprl's constructive type theory that justifies a useful embedding of the logic of the HOL theorem prover inside Nuprl. The embedding gives Nuprl effective access to most of the large body of formalized mathematics that the HOL community has amassed over the last dec ..."
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Cited by 29 (2 self)
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We give a new semantics for Nuprl's constructive type theory that justifies a useful embedding of the logic of the HOL theorem prover inside Nuprl. The embedding gives Nuprl effective access to most of the large body of formalized mathematics that the HOL community has amassed over the last decade. The new semantics is dramatically simpler than the old, and gives a novel and general way of adding settheoretic equivalence classes to untyped functional programming languages.
A Tutorial on Coinduction and Functional Programming
 IN GLASGOW FUNCTIONAL PROGRAMMING WORKSHOP
, 1994
"... Coinduction is an important tool for reasoning about unbounded structures. This tutorial explains the foundations of coinduction, and shows how it justifies intuitive arguments about lazy streams, of central importance to lazy functional programmers. We explain from first principles a theory based ..."
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Cited by 27 (1 self)
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Coinduction is an important tool for reasoning about unbounded structures. This tutorial explains the foundations of coinduction, and shows how it justifies intuitive arguments about lazy streams, of central importance to lazy functional programmers. We explain from first principles a theory based on a new formulation of bisimilarity for functional programs, which coincides exactly with Morrisstyle contextual equivalence. We show how to prove properties of lazy streams by coinduction and derive Bird and Wadler's Take Lemma, a wellknown proof technique for lazy streams.
Monads, effects and transformations
 Electronic Notes in Theoretical Computer Science
, 1999
"... Abstract We define a typed compiler intermediate language, MILlite, which incorporates computational types refined with effect information. We characterise MILlite observational congruence by using Howe's method to prove a ciu theorem for the language in terms of a termination predicate defined di ..."
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Cited by 27 (9 self)
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Abstract We define a typed compiler intermediate language, MILlite, which incorporates computational types refined with effect information. We characterise MILlite observational congruence by using Howe's method to prove a ciu theorem for the language in terms of a termination predicate defined directly on the term. We then define a logical predicate which captures an observable version of the intended meaning of each of our effect annotations. Having proved the fundamental theorem for this predicate, we use it with the ciu theorem to validate a number of effectbased transformations performed by the MLj compiler for Standard ML.
Variations on Algebra: monadicity and generalisations of equational theories
 Formal Aspects of Computing
, 2001
"... this paper the author was partially supported by an SERC/EPSRC Advanced Research Fellowship, EPSRC Research grant GR/L54639, and EU Working Group APPSEM ..."
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Cited by 25 (0 self)
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this paper the author was partially supported by an SERC/EPSRC Advanced Research Fellowship, EPSRC Research grant GR/L54639, and EU Working Group APPSEM
The Impact of the Lambda Calculus in Logic and Computer Science
 Bulletin of Symbolic Logic
, 1997
"... One of the most important contributions of A. Church to logic is his invention of the lambda calculus. We present the genesis of this theory and its two major areas of application: the representation of computations and the resulting functional programming languages on the one hand and the represent ..."
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Cited by 23 (0 self)
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One of the most important contributions of A. Church to logic is his invention of the lambda calculus. We present the genesis of this theory and its two major areas of application: the representation of computations and the resulting functional programming languages on the one hand and the representation of reasoning and the resulting systems of computer mathematics on the other hand. Acknowledgement. The following persons provided help in various ways. Erik Barendsen, Jon Barwise, Johan van Benthem, Andreas Blass, Olivier Danvy, Wil Dekkers, Marko van Eekelen, Sol Feferman, Andrzej Filinski, Twan Laan, Jan Kuper, Pierre Lescanne, Hans Mooij, Robert Maron, Rinus Plasmeijer, Randy Pollack, Kristoffer Rose, Richard Shore, Rick Statman and Simon Thompson. Partial support came from the European HCM project Typed lambda calculus (CHRXCT920046), the Esprit Working Group Types (21900) and the Dutch NWO project WINST (612316607). 1. Introduction This paper is written to honor Church's gr...
A Fully Abstract Semantics for a Concurrent Functional Language With Monadic Types
, 1995
"... This paper presents a typed higherorder concurrent functional programming language, based on Moggi's monadic metalanguage and Reppy's Concurrent ML. We present an operational semantics for the language, and show that a higherorder variant of the traces model is fully abstract for maytesting. This p ..."
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Cited by 21 (4 self)
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This paper presents a typed higherorder concurrent functional programming language, based on Moggi's monadic metalanguage and Reppy's Concurrent ML. We present an operational semantics for the language, and show that a higherorder variant of the traces model is fully abstract for maytesting. This proof uses a program logic based on HennessyMilner logic and Abramsky's domain theory in logical form.