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A Fold for All Seasons
 IN PROC. CONFERENCE ON FUNCTIONAL PROGRAMMING LANGUAGES AND COMPUTER ARCHITECTURE
, 1993
"... Generic control operators, such as fold, can be generated from algebraic type definitions. The class of types to which these techniques are applicable is generalized to all algebraic types definable in languages such as Miranda and ML, i.e. mutually recursive sumsofproducts with tuples and functio ..."
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Cited by 113 (15 self)
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Generic control operators, such as fold, can be generated from algebraic type definitions. The class of types to which these techniques are applicable is generalized to all algebraic types definable in languages such as Miranda and ML, i.e. mutually recursive sumsofproducts with tuples and function types. Several other useful generic operators, also applicable to every type in this class, also are described. A normalization algorithm which automatically calculates improvements to programs expressed in a language based upon folds is described. It reduces programs, expressed using fold as the exclusive control operator, to a canonical form. Based upon a generic promotion theorem, the algorithm is facilitated by the explicit structure of fold programs rather than using an analysis phase to search for implicit structure. Canonical programs are minimal in the sense that they contain the fewest number of fold operations. Because of this property, the normalization algorithm has important ...
Revised 4 report on the algorithmic language Scheme
 Lisp Pointers
, 1991
"... The report gives a defining description of the programming language Scheme. Scheme is a statically scoped and properly tailrecursive dialect of the Lisp programming language invented by Guy Lewis Steele Jr. and Gerald Jay Sussman. It was designed to have an exceptionally clear and simple semantics ..."
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Cited by 80 (1 self)
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The report gives a defining description of the programming language Scheme. Scheme is a statically scoped and properly tailrecursive dialect of the Lisp programming language invented by Guy Lewis Steele Jr. and Gerald Jay Sussman. It was designed to have an exceptionally clear and simple semantics and few different ways to form expressions. A wide variety of programming paradigms, including imperative, functional, and message passing styles, find convenient expression in Scheme. The introduction offers a brief history of the language and of the report. The first three chapters present the fundamental ideas of the language and describe the notational conventions used for describing the language and for writing programs in the language.
Proper Tail Recursion and Space Efficiency
, 1998
"... The IEEE/ANSI standard for Scheme requires implementations to be properly tail recursive. This ensures that portable code can rely upon the space efficiency of continuationpassing style and other idioms. On its face, proper tail recursion concerns the efficiency of procedure calls that occur within ..."
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Cited by 60 (1 self)
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The IEEE/ANSI standard for Scheme requires implementations to be properly tail recursive. This ensures that portable code can rely upon the space efficiency of continuationpassing style and other idioms. On its face, proper tail recursion concerns the efficiency of procedure calls that occur within a tail context. When examined closely, proper tail recursion also depends upon the fact that garbage collection can be asymptotically more spaceefficient than Algollike stack allocation. Proper tail recursion is not the same as ad hoc tail call optimization in stackbased languages. Proper tail recursion often precludes stack allocation of variables, but yields a welldefined asymptotic space complexity that can be relied upon by portable programs. This paper offers a formal and implementationindependent definition of proper tail recursion for Scheme. It also shows how an entire family of reference implementations can be used to characterize related safeforspace properties, and proves ...
For a Better Support of Static Data Flow
 Functional Programming Languages and Computer Architecture
"... . This paper identifies and solves a class of problems that arise in binding time analysis and more generally in partial evaluation of programs: the approximation and loss of static information due to dynamic expressions with static subexpressions. Solving this class of problems yields substantial b ..."
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Cited by 59 (16 self)
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. This paper identifies and solves a class of problems that arise in binding time analysis and more generally in partial evaluation of programs: the approximation and loss of static information due to dynamic expressions with static subexpressions. Solving this class of problems yields substantial binding time improvements and thus dramatically better results not only in the case of partial evaluation but also for static analyses of programs  this last point actually is related to a theoretical result obtained by Nielson. Our work can also be interpreted as providing a solution to the problem of conditionally static data, the dual of partially static data. We point out which changes in the control flow of a source program may improve its static data flow. Unfortunately they require one to iterate earlier phases of partial evaluation. We show how these changes are subsumed by transforming the source program into continuationpassing style (CPS). The transformed programs get specializ...
The UnderAppreciated Unfold
 In Proceedings of the Third ACM SIGPLAN International Conference on Functional Programming
, 1998
"... Folds are appreciated by functional programmers. Their dual, unfolds, are not new, but they are not nearly as well appreciated. We believe they deserve better. To illustrate, we present (indeed, we calculate) a number of algorithms for computing the breadthfirst traversal of a tree. We specify brea ..."
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Cited by 49 (10 self)
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Folds are appreciated by functional programmers. Their dual, unfolds, are not new, but they are not nearly as well appreciated. We believe they deserve better. To illustrate, we present (indeed, we calculate) a number of algorithms for computing the breadthfirst traversal of a tree. We specify breadthfirst traversal in terms of levelorder traversal, which we characterize first as a fold. The presentation as a fold is simple, but it is inefficient, and removing the inefficiency makes it no longer a fold. We calculate a characterization as an unfold from the characterization as a fold; this unfold is equally clear, but more efficient. We also calculate a characterization of breadthfirst traversal directly as an unfold; this turns out to be the `standard' queuebased algorithm.
Revised^3 Report on the Algorithmic Language Scheme
, 1991
"... Programming languages should be designed not by piling feature on top of feature, but by removing the weaknesses and restrictions that make additional features appear necessary. Scheme demonstrates that a very small number of rules for forming expressions, with no restrictions on how they are compos ..."
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Cited by 46 (2 self)
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Programming languages should be designed not by piling feature on top of feature, but by removing the weaknesses and restrictions that make additional features appear necessary. Scheme demonstrates that a very small number of rules for forming expressions, with no restrictions on how they are composed, suffice to form a practical and efficient programming language that is flexible enough to support most of the major programming paradigms in use today.
A Survey and Classification of some Program Transformation Approaches and Techniques
 In TC2 IFIP Working Conference on Program Specification and Transformation
, 1987
"... Program transformation is a means to formally develop efficient programs from lucid specifications. A representative sample of the diverse range of program transformation research is classified into several different approaches based upon the motivations for and styles of constructing such formal de ..."
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Cited by 44 (0 self)
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Program transformation is a means to formally develop efficient programs from lucid specifications. A representative sample of the diverse range of program transformation research is classified into several different approaches based upon the motivations for and styles of constructing such formal developments. Individual techniques for supporting construction of developments are also surveyed, and are related to the various approaches.
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