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A Core Calculus of Dependency
- IN PROC. 26TH ACM SYMP. ON PRINCIPLES OF PROGRAMMING LANGUAGES (POPL
, 1999
"... Notions of program dependency arise in many settings: security, partial evaluation, program slicing, and call-tracking. We argue that there is a central notion of dependency common to these settings that can be captured within a single calculus, the Dependency Core Calculus (DCC), a small extension ..."
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Cited by 248 (21 self)
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Notions of program dependency arise in many settings: security, partial evaluation, program slicing, and call-tracking. We argue that there is a central notion of dependency common to these settings that can be captured within a single calculus, the Dependency Core Calculus (DCC), a small extension of Moggi's computational lambda calculus. To establish this thesis, we translate typed calculi for secure information flow, binding-time analysis, slicing, and call-tracking into DCC. The translations help clarify aspects of the source calculi. We also define a semantic model for DCC and use it to give simple proofs of noninterference results for each case.
Provenance as dependency analysis
- Proceedings of the 11th International Symposium on Database Programming Languages (DBPL 2007), number 4797 in LNCS
, 2007
"... Abstract. Provenance is information recording the source, derivation, or history of some information. Provenance tracking has been studied in a variety of settings; however, although many design points have been explored, the mathematical or semantic foundations of data provenance have received comp ..."
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Cited by 42 (16 self)
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Abstract. Provenance is information recording the source, derivation, or history of some information. Provenance tracking has been studied in a variety of settings; however, although many design points have been explored, the mathematical or semantic foundations of data provenance have received comparatively little attention. In this paper, we argue that dependency analysis techniques familiar from program analysis and program slicing provide a formal foundation for forms of provenance that are intended to show how (part of) the output of a query depends on (parts of) its input. We introduce a semantic characterization of such dependency provenance, show that this form of provenance is not computable, and provide dynamic and static approximation techniques. 1
Functional Programs that Explain their Work
"... We present techniques that enable higher-order functional computations to “explain ” their work by answering questions about how parts of their output were calculated. As explanations, we consider the traditional notion of program slices, which we show can be inadequate, and propose a new notion: tr ..."
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Cited by 5 (3 self)
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We present techniques that enable higher-order functional computations to “explain ” their work by answering questions about how parts of their output were calculated. As explanations, we consider the traditional notion of program slices, which we show can be inadequate, and propose a new notion: trace slices. We present techniques for specifying flexible and rich slicing criteria based on partial expressions, parts of which have been replaced by holes. We characterise program slices in an algorithm-independent fashion and show that a least slice for a given criterion exists. We then present an algorithm, called unevaluation, for computing least program slices from computations reified as traces. Observing a limitation of program slices, we develop a notion of trace slice as another form of explanation and present an algorithm for computing them. The unevaluation algorithm can be applied to any subtrace of a trace slice to compute a program slice whose evaluation generates that subtrace. This close correspondence between programs, traces, and their slices can enable the programmer to understand a computation interactively, in terms of the programming language in which the computation is expressed. We present an implementation in the form of a tool, discuss some important practical implementation concerns and present some techniques for addressing them.
Lightweight Program Specialization via Dynamic Slicing
, 2005
"... Program slicing is a well-known technique that extracts from a program those statements which are relevant to a particular criterion. While static slicing does not consider any input data, dynamic slices are computed from a particular program execution. Thus, dynamic slicers are usually easier to de ..."
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Cited by 2 (0 self)
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Program slicing is a well-known technique that extracts from a program those statements which are relevant to a particular criterion. While static slicing does not consider any input data, dynamic slices are computed from a particular program execution. Thus, dynamic slicers are usually easier to design and implement. In this work, we present a program specialization technique for lazy functional logic programming which is based on dynamic slicing. Our method exploits the code size reduction capabilities of slicing in order to produce a version of the original program specialized w.r.t. a given criterion. We also introduce some simple, post-processing transformations that allow us to further simplify the specialized program. The kind of specialization performed by our approach cannot be achieved with other related techniques like partial evaluation.
L.S.: Higher-Order Lazy Functional Slicing
"... Abstract: Program slicing is a well known family of techniques intended to identify and isolate code fragments which depend on, or are depended upon, specific program entities. This is particularly useful in the areas of reverse engineering, program understanding, testing and software maintenance. M ..."
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Cited by 1 (1 self)
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Abstract: Program slicing is a well known family of techniques intended to identify and isolate code fragments which depend on, or are depended upon, specific program entities. This is particularly useful in the areas of reverse engineering, program understanding, testing and software maintenance. Most slicing methods, and corresponding tools, target either the imperative or the object oriented paradigms, where program slices are computed with respect to a variable or a program statement. Taking a complementary point of view, this paper focuses on the slicing of higher-order functional programs under a lazy evaluation strategy. A prototype of a Haskell slicer, built as proof-of-concept for these ideas, is also introduced.
Dynamic Slicing of Lazy Functional Programs Based on Redex Trails
, 2007
"... Tracing computations is a widely used methodology for program debugging. Lazy languages, however, pose new demands on tracing techniques because following the actual trace of a computation is generally useless. Typically, tracers for lazy languages rely on the construction of a redex trail, a graph ..."
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Cited by 1 (0 self)
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Tracing computations is a widely used methodology for program debugging. Lazy languages, however, pose new demands on tracing techniques because following the actual trace of a computation is generally useless. Typically, tracers for lazy languages rely on the construction of a redex trail, a graph that stores the reductions performed in a computation. While tracing provides a significant help for locating bugs, the task still remains complex. A well-known debugging technique for imperative programs is based on dynamic slicing, a method for finding the program statements that influence the computation of a value for a specific program input. In this work, we introduce a novel technique for dynamic slicing in first-order lazy functional languages. Rather than starting from scratch, our technique relies on (a slight extension of) redex trails. We provide a notion of dynamic slice and introduce a method to compute it from the redex trail of a computation. We also sketch the extension of our technique to deal with a functional logic language. A clear advantage of our proposal is that one can enhance existing tracers with slicing capabilities with a modest implementation effort, since the same data structure (the redex trail) can be used for both tracing and slicing.
Under consideration for publication in Theory and Practice of Logic Programming 1 Forward Slicing of Functional Logic Programs by Partial Evaluation∗
, 2005
"... Program slicing has been mainly studied in the context of imperative languages, where it has been applied to a wide variety of software engineering tasks, like program understanding, maintenance, debugging, testing, code reuse, etc. This work introduces the first forward slicing technique for declar ..."
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Program slicing has been mainly studied in the context of imperative languages, where it has been applied to a wide variety of software engineering tasks, like program understanding, maintenance, debugging, testing, code reuse, etc. This work introduces the first forward slicing technique for declarative multi-paradigm programs which integrate features from functional and logic programming. Basically, given a program and a slicing criterion (a function call in our setting), the computed forward slice contains those parts of the original program which are reachable from the slicing criterion. Our approach to program slicing is based on an extension of (online) partial evaluation. Therefore, it provides a simple way to develop program slicing tools from existing partial evaluators and helps to clarify the relation between both methodologies. A slicing tool for the multi-paradigm language Curry, which demonstrates the usefulness of our approach, has been implemented in Curry itself.
A Core Calculus of Dependency
"... ...partial evaluation, program slicing, and call-tracking. We argue that there is a central notion of dependency common to these settings that can be captured within a single calculus, the Dependency Core Calculus (DCC), a small extension of Moggi’s computational lambda calculus. To establish this t ..."
Abstract
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...partial evaluation, program slicing, and call-tracking. We argue that there is a central notion of dependency common to these settings that can be captured within a single calculus, the Dependency Core Calculus (DCC), a small extension of Moggi’s computational lambda calculus. To establish this thesis, we translate typed calculi for secure information flow, binding-time analysis, slicing, and call-tracking into DCC. The translations help clarify aspects of the source calculi. We also define a semantic model for DCC and use it to give simple proofs of noninterference results for each case.
ABSTRACT Dynamic Slicing Based on Redex Trails ∗
"... Tracing computations is a widely used methodology for program debugging. Lazy languages, in particular, pose new demands on tracing techniques since following the actual trace of a computation is generally useless. Typically, they rely on the construction of a redex trail, a graph that describes the ..."
Abstract
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Tracing computations is a widely used methodology for program debugging. Lazy languages, in particular, pose new demands on tracing techniques since following the actual trace of a computation is generally useless. Typically, they rely on the construction of a redex trail, a graph that describes the reductions of a computation and its relationships. While tracing provides a significant help for locating bugs, the task still remains complex. A well-known debugging technique for imperative programs is based on dynamic slicing, a method to find the program statements that influence the computation of a value for a specific program input. In this work, we introduce a novel technique for dynamic slicing in lazy functional logic languages. Rather than starting from scratch, our technique relies on (a slight extension of) redex trails. We provide a method to compute a correct and minimal dynamic slice from the redex trail of a computation. A clear advantage of our proposal is that one can enhance existing tracers with slicing capabilities with a modest implementation effort, since the same data structure (the redex trail) can be used for both tracing and slicing.
