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Fully abstract semantics for observably sequential languages
 Information and Computation
, 1994
"... One of the major challenges in denotational semantics is the construction of a fully abstract semantics for a higherorder sequential programming language. For the past fifteen years, research on this problem has focused on developing a semantics for PCF, an idealized functional programming language ..."
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Cited by 49 (4 self)
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One of the major challenges in denotational semantics is the construction of a fully abstract semantics for a higherorder sequential programming language. For the past fifteen years, research on this problem has focused on developing a semantics for PCF, an idealized functional programming language based on the typed λcalculus. Unlike most practical languages, PCF has no facilities for observing and exploiting the evaluation order of arguments to procedures. Since we believe that these facilities play a crucial role in sequential computation, this paper focuses on a sequential extension of PCF, called SPCF, that includes two classes of control operators: a possibly empty set of error generators and a collection of catch and throw constructs. For each set of error generators, the paper presents a fully abstract semantics for SPCF. If the set of error generators is empty, the semantics interprets all procedures—including catch and throw—as BerryCurien sequential algorithms. If the language contains error generators, procedures denote manifestly sequential functions. The manifestly sequential functions form a Scott domain that is isomorphic to a domain of decision trees, which is the natural
Back to Direct Style
, 1994
"... This paper describes the transformation of lambdaterms from continuationpassing style (CPS) to direct style. This transformation is the left inverse of Plotkin's lefttoright callbyvalue CPS encoding for the pure lambdacalculus. Not all terms are CPS terms, and not all CPS terms encode a left ..."
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Cited by 49 (22 self)
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This paper describes the transformation of lambdaterms from continuationpassing style (CPS) to direct style. This transformation is the left inverse of Plotkin's lefttoright callbyvalue CPS encoding for the pure lambdacalculus. Not all terms are CPS terms, and not all CPS terms encode a lefttoright callbyvalue evaluation. These CPS terms are characterized here; they can be mapped back to direct style. In addition, the two transformations  to continuationpassing style and to direct style  are factored using a language where all intermediate values are named and their computation is sequentialized. The issue of proper tailrecursion is also addressed.
Explaining Crossover and Superiority as LefttoRight Evaluation
 LINGUISTICS AND PHILOSOPHY
, 2006
"... We present a general theory of scope and binding in which both crossover and superiority violations are ruled out by one key assumption: that natural language expressions are normally evaluated (processed) from left to right. Our theory is an extension of Shan’s (2002) account of multiplewh questi ..."
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Cited by 45 (12 self)
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We present a general theory of scope and binding in which both crossover and superiority violations are ruled out by one key assumption: that natural language expressions are normally evaluated (processed) from left to right. Our theory is an extension of Shan’s (2002) account of multiplewh questions, combining continuations (Barker, 2002) and dynamic typeshifting. Like other continuationbased analyses, but unlike most other treatments of crossover or superiority, our analysis is directly compositional (in the sense of, e.g., Jacobson, 1999). In particular, it does not postulate a level of Logical Form or any other representation distinct from surface syntax. One advantage of using continuations is that they are the standard tool for modeling orderofevaluation in programming languages. This provides us with a natural and independently motivated characterization of what it means to evaluate expressions from left to right. We give a combinatory categorial grammar that models the syntax and the semantics of quantifier scope and whquestion formation. It allows quantificational binding but not crossover, insitu wh but not superiority violations. In addition, the analysis automatically accounts for a variety of sentence types involving binding in the presence of pied piping, including reconstruction cases such as Whose criticism of hisi mother did each personi resent?
Privacy via Subsumption
 Information and Computation
, 1998
"... We describe an object calculus that allows both extension of objects and full width subtyping (hiding arbitrary components). In contrast to other proposals, the types of our calculus do not mention "missing " methods. To avoid type unsoundness, the calculus mediates all interaction with objects via ..."
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Cited by 44 (2 self)
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We describe an object calculus that allows both extension of objects and full width subtyping (hiding arbitrary components). In contrast to other proposals, the types of our calculus do not mention "missing " methods. To avoid type unsoundness, the calculus mediates all interaction with objects via "dictionaries" that resemble the method dispatch tables in conventional implementations. Private fields and methods can be modeled and enforced by scoping restrictions: forgetting a field or method through subsumption makes it private. We prove that the type system is sound, give a variant which allows covariant self types, and give some examples of the expressiveness of the calculus. 1 Introduction One of the most important principles of software engineering is information hiding: the ability to build and enforce data or procedural abstractions in order to make programs readable and maintainable. Most objectoriented programming languages provide direct support for information hiding. Clas...
Observable Sequentiality and Full Abstraction
 In Proceedings of POPL ’92
, 1992
"... ion Robert Cartwright Matthias Felleisen Department of Computer Science Rice University Houston, TX 772511892 Abstract One of the major challenges in denotational semantics is the construction of fully abstract models for sequential programming languages. For the past fifteen years, research o ..."
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Cited by 39 (5 self)
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ion Robert Cartwright Matthias Felleisen Department of Computer Science Rice University Houston, TX 772511892 Abstract One of the major challenges in denotational semantics is the construction of fully abstract models for sequential programming languages. For the past fifteen years, research on this problem has focused on developing models for PCF, an idealized functional programming language based on the typed lambda calculus. Unlike most practical languages, PCF has no facilities for observing and exploiting the evaluation order of arguments in procedures. Since we believe that such facilities are crucial for understanding the nature of sequential computation, this paper focuses on a sequential extension of PCF (called SPCF) that includes two classes of control operators: error generators and escape handlers. These new control operators enable us to construct a fully abstract model for SPCF that interprets higher types as sets of errorsensitive functions instead of continuous...
Monads and Composable Continuations
, 1993
"... . Moggi's use of monads to factor semantics is used to model the composable continuations of Danvy and Filinski. This yields some insights into the type systems proposed by Murthy and by Danvy and Filinski. Interestingly, modelling some aspects of composable continuations requires a structure that i ..."
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Cited by 35 (1 self)
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. Moggi's use of monads to factor semantics is used to model the composable continuations of Danvy and Filinski. This yields some insights into the type systems proposed by Murthy and by Danvy and Filinski. Interestingly, modelling some aspects of composable continuations requires a structure that is almost, but not quite, a monad. 1. Introduction Continuationpassing style was introduced to model one feature of programming languages  the jump  and to explicate the execution order of programs [14, 12]. Recently, Moggi has shown how monads, a notion from category theory, generalise the continuationpassing style transformation [9]. Monads can model a wide variety of features, including continuations, state, exceptions, inputoutput, nondeterminism, and parallellism. Monads have also been applied both as a way of structuring functional programs [16, 17] and as a way of introducing new features into functional languages [11]. It begins to seem as if any feature of a programming lang...
Reasoning with Continuations II: Full Abstraction for Models of Control
 In Proceedings of the 1990 ACM Conference on Lisp and Functional Programming
, 1990
"... A fully abstract model of a programming language assigns the same meaning to two terms if and only if they have the same operational behavior. Such models are wellknown for functional languages but little is known about extended functional languages with sophisticated control structures. We show th ..."
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Cited by 32 (4 self)
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A fully abstract model of a programming language assigns the same meaning to two terms if and only if they have the same operational behavior. Such models are wellknown for functional languages but little is known about extended functional languages with sophisticated control structures. We show that a direct model with error values and the conventional continuation model are adequate for functional languages augmented with first and higherorder control facilities, respectively. Furthermore, both models become fully abstract on adding a control delimiter and a parallel conditional to the programming languages.
Delimited Dynamic Binding
, 2006
"... Dynamic binding and delimited control are useful together in many settings, including Web applications, database cursors, and mobile code. We examine this pair of language features to show that the semantics of their interaction is illdefined yet not expressive enough for these uses. We solve this ..."
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Cited by 31 (11 self)
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Dynamic binding and delimited control are useful together in many settings, including Web applications, database cursors, and mobile code. We examine this pair of language features to show that the semantics of their interaction is illdefined yet not expressive enough for these uses. We solve this open and subtle problem. We formalise a typed language DB+DC that combines a calculus DB of dynamic binding and a calculus DC of delimited control. We argue from theoretical and practical points of view that its semantics should be based on delimited dynamic binding: capturing a delimited continuation closes over part of the dynamic environment, rather than all or none of it; reinstating the captured continuation supplements the dynamic environment, rather than replacing or inheriting it. We introduce a type and reductionpreserving translation from DB + DC to DC, which proves that delimited control macroexpresses dynamic binding. We use this translation to implement DB + DC in Scheme, OCaml, and Haskell. We extend DB + DC with mutable dynamic variables and a facility to obtain not only the latest binding of a dynamic variable but also older bindings. This facility provides for stack inspection and (more generally) folding over the execution context as an inductive data structure.
Region Analysis and the Polymorphic Lambda Calculus
 In Proc. of the 14th Annual IEEE Symposium on Logic in Computer Science
, 1999
"... We show how to translate the region calculus of Tofte and Talpin, a typed lambda calculus that can statically delimit the lifetimes of objects, into an extension of the polymorphic lambda calculus called F # . We give a denotational semantics of F # , and use it to give a simple and abstract proof o ..."
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Cited by 28 (0 self)
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We show how to translate the region calculus of Tofte and Talpin, a typed lambda calculus that can statically delimit the lifetimes of objects, into an extension of the polymorphic lambda calculus called F # . We give a denotational semantics of F # , and use it to give a simple and abstract proof of the correctness of memory deallocation. 1 Introduction Implementations of modern programming languages divide dynamically allocated memory into two parts. The stack is used for data that has a simple lastin, firstout lifetime determined by block structure; the other part (often called the heap) is used for data whose lifetime extends beyond the scope of program blocks. The heap is periodically "garbage collected" to reclaim memory that is no longer needed. Tofte and Talpin's region calculus [23] attempts to unify these two styles of memory management. The region calculus divides memory into regions, and provides a local scoping mechanism for those regions. Every value created by the pro...
A rational deconstruction of Landin’s SECD machine
 Implementation and Application of Functional Languages, 16th International Workshop, IFL’04, number 3474 in Lecture Notes in Computer Science
, 2004
"... Abstract. Landin’s SECD machine was the first abstract machine for applicative expressions, i.e., functional programs. Landin’s J operator was the first control operator for functional languages, and was specified by an extension of the SECD machine. We present a family of evaluation functions corre ..."
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Cited by 27 (19 self)
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Abstract. Landin’s SECD machine was the first abstract machine for applicative expressions, i.e., functional programs. Landin’s J operator was the first control operator for functional languages, and was specified by an extension of the SECD machine. We present a family of evaluation functions corresponding to this extension of the SECD machine, using a series of elementary transformations (transformation into continuationpassing style (CPS) and defunctionalization, chiefly) and their left inverses (transformation into direct style and refunctionalization). To this end, we modernize the SECD machine into a bisimilar one that operates in lockstep with the original one but that (1) does not use a data stack and (2) uses the callersave rather than the calleesave convention for environments. We also identify that the dump component of the SECD machine is managed in a calleesave way. The callersave counterpart of the modernized SECD machine precisely corresponds to Thielecke’s doublebarrelled continuations and to Felleisen’s encoding of J in terms of call/cc. We then variously characterize the J operator in terms of CPS and in terms of delimitedcontrol operators in the CPS hierarchy. As a byproduct, we also present several reduction semantics for applicative expressions