We report on the design and implementation of an extensible programminglanguage and its intrinsic support for formal verification. Our language is targeted at low-level programming of infrastructure like operating sy...
详细信息
We report on the design and implementation of an extensible programminglanguage and its intrinsic support for formal verification. Our language is targeted at low-level programming of infrastructure like operating systems and runtime systems. It is based on a cross-platform core combining characteristics of assembly languages and compiler intermediate languages. From this foundation, we take literally the saying that C is a "macro assembly language": we introduce an expressive notion of certified low-level macros, sufficient to build up the usual features of C and beyond as macros with no special support in the core. Furthermore, our macros have integrated support for strongest postcondition calculation and verification condition generation, so that we can provide a high-productivity formal verification environment within Coq for programs composed from any combination of macros. Our macro interface is expressive enough to support features that low-level programs usually only access through external tools with no formal guarantees, such as declarative parsing or SQL-inspired querying. The abstraction level of these macros only imposes a compile-time cost, via the execution of functional Coq programs that compute programs in our intermediate language;but the run-time cost is not substantially greater than for more conventional C code. We describe our experiences constructing a full C-like language stack using macros, with some experiments on the verifiability and performance of individual programs running on that stack.
The field of quantum algorithms is vibrant. Still, there is currently a lack of programminglanguages for describing quantum computation on a practical scale, i.e., not just at the level of toy problems. We address th...
详细信息
ISBN:
(纸本)9781450320146
The field of quantum algorithms is vibrant. Still, there is currently a lack of programminglanguages for describing quantum computation on a practical scale, i.e., not just at the level of toy problems. We address this issue by introducing Quipper, a scalable, expressive, functional, higher-order quantum programminglanguage. Quipper has been used to program a diverse set of non-trivial quantum algorithms, and can generate quantum gate representations using trillions of gates. It is geared towards a model of computation that uses a classical computer to control a quantum device, but is not dependent on any particular model of quantum hardware. Quipper has proven effective and easy to use, and opens the door towards using formal methods to analyze quantum algorithms.
We propose a technique to efficiently search a large family of abstractions in order to prove a query using a parametric dataflow analysis. Our technique either finds the cheapest such abstraction or shows that none e...
详细信息
ISBN:
(纸本)9781450320146
We propose a technique to efficiently search a large family of abstractions in order to prove a query using a parametric dataflow analysis. Our technique either finds the cheapest such abstraction or shows that none exists. It is based on counterexample-guided abstraction refinement but applies a novel meta-analysis on abstract counterexample traces to efficiently find abstractions that are incapable of proving the query. We formalize the technique in a generic framework and apply it to two analyses: a type-state analysis and a thread-escape analysis. We demonstrate the effectiveness of the technique on a suite of Java benchmark programs.
High-performance computing applications, such as auto-tuners and domain-specific languages, rely on generative programming techniques to achieve high performance and portability. However, these systems are often imple...
详细信息
ISBN:
(纸本)9781450320146
High-performance computing applications, such as auto-tuners and domain-specific languages, rely on generative programming techniques to achieve high performance and portability. However, these systems are often implemented in multiple disparate languages and perform code generation in a separate process from program execution, making certain optimizations difficult to engineer. We leverage a popular scripting language, Lua, to stage the execution of a novel low-level language, Terra. Users can implement optimizations in the high-level language, and use built-in constructs to generate and execute high-performance Terra code. To simplify meta-programming, Lua and Terra share the same lexical environment, but, to ensure performance, Terra code can execute independently of Lua's runtime. We evaluate our design by reimplementing existing multi-language systems entirely in Terra. Our Terra-based auto-tuner for BLAS routines performs within 20% of ATLAS, and our DSL for stencil computations runs 2.3x faster than hand-written C.
Graphical user interfaces (GUIs) mediate many of our interactions with computers. Functional Reactive programming (FRP) is a promising approach to GUI design, providing high-level, declarative, compositional abstracti...
详细信息
ISBN:
(纸本)9781450320146
Graphical user interfaces (GUIs) mediate many of our interactions with computers. Functional Reactive programming (FRP) is a promising approach to GUI design, providing high-level, declarative, compositional abstractions to describe user interactions and time-dependent computations. We present Elm, a practical FRP language focused on easy creation of responsive GUIs. Elm has two major features: simple declarative support for Asynchronous FRP; and purely functional graphical layout. Asynchronous FRP allows the programmer to specify when the global ordering of event processing can be violated, and thus enables efficient concurrent execution of FRP programs; long-running computation can be executed asynchronously and not adversely affect the responsiveness of the user interface. Layout in Elm is achieved using a purely functional declarative framework that makes it simple to create and combine text, images, and video into rich multimedia displays. Together, Elm's two major features simplify the complicated task of creating responsive and usable GUIs.
作者:
Kim, Ju-WhanNam, Tek-JinCIDR Lab
Department of Industrial Design KAIST 291 Daehak-ro Yuseong-gu Daejeon 305-701 Korea Republic of
Prototyping of gestural interactions in the early phase of design is one of the most challenging tasks for designers without advanced programming skills. Relating users' input from gesture-based sensor values requ...
详细信息
Live programming allows programmers to edit the code of a running program and immediately see the effect of the code changes. This tightening of the traditional edit-compile-run cycle reduces the cognitive gap between...
详细信息
ISBN:
(纸本)9781450320146
Live programming allows programmers to edit the code of a running program and immediately see the effect of the code changes. This tightening of the traditional edit-compile-run cycle reduces the cognitive gap between program code and execution, improving the learning experience of beginning programmers while boosting the productivity of seasoned ones. Unfortunately, live programming is difficult to realize in practice as imperative languages lack well-defined abstraction boundaries that make live programming responsive or its feedback comprehensible. This paper enables live programming for user interface programming by cleanly separating the rendering and non-rendering aspects of a UI program, allowing the display to be refreshed on a code change without restarting the program. A type and effect system formalizes this separation and provides an evaluation model that incorporates the code update step. By putting live programming on a more formal footing, we hope to enable critical and technical discussion of live programming systems.
Pattern matching, an important feature of functional languages, is in conflict with data abstraction and extensibility, which are central to object-oriented languages. Modal abstraction offers an integration of deep p...
详细信息
ISBN:
(纸本)9781450320146
Pattern matching, an important feature of functional languages, is in conflict with data abstraction and extensibility, which are central to object-oriented languages. Modal abstraction offers an integration of deep pattern matching and convenient iteration abstractions into an object-oriented setting; however, because of data abstraction, it is challenging for a compiler to statically verify properties such as exhaustiveness. In this work, we extend modal abstraction in the JMatch language to support static, modular reasoning about exhaustiveness and redundancy. New matching specifications allow these properties to be checked using an SMT solver. We also introduce expressive pattern-matching constructs. Our evaluation shows that these new features enable more concise code and that the performance of checking exhaustiveness and redundancy is acceptable.
暂无评论