Mainstream programminglanguages like Java have limited support for language extensibility. Without mechanisms for syntactic abstraction, new programming styles can only be embedded in the form of libraries, limiting ...
详细信息
ISBN:
(纸本)9781450344463
Mainstream programminglanguages like Java have limited support for language extensibility. Without mechanisms for syntactic abstraction, new programming styles can only be embedded in the form of libraries, limiting expressiveness. In this paper, we present Recaf, a lightweight tool for creating Java dialects;effectively extending Java with new language constructs and user defined semantics. The Recaf compiler generically transforms designated method bodies to code that is parameterized by a semantic factory (Object Algebra), defined in plain Java. The implementation of such a factory defines the desired runtime semantics. We applied our design to produce several examples from a diverse set of programming styles and two case studies: we define i) extensions for generators, asynchronous computations and asynchronous streams and ii) a Domain-Specific language (DSL) for Parsing Expression Grammars (PEGs), in a few lines of code.
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.
We present a way to restrict recursive inheritance without sacrificing the benefits of F-bounded polymorphism. In particular, we distinguish two new concepts, materials and shapes, and demonstrate through a survey of ...
详细信息
ISBN:
(纸本)9781450327848
We present a way to restrict recursive inheritance without sacrificing the benefits of F-bounded polymorphism. In particular, we distinguish two new concepts, materials and shapes, and demonstrate through a survey of 13.5 million lines of open-source generic-Java code that these two concepts never actually overlap in practice. With this Material-Shape Separation, we prove that even naive type-checking algorithms are sound and complete, some of which address problems that were unsolvable even under the existing proposals for restricting inheritance. We illustrate how the simplicity of our design reflects the design intuitions employed by programmers and potentially enables new features coming into demand for upcoming programminglanguages.
This paper presents the design and implementation of Event-driven State-machines programming (ESP) - a language for programmable devices. In traditional languages, like C, using event-driven state-machines forces a tr...
详细信息
ISBN:
(纸本)9781581134148
This paper presents the design and implementation of Event-driven State-machines programming (ESP) - a language for programmable devices. In traditional languages, like C, using event-driven state-machines forces a tradeoff that requires giving up ease of development and reliability to achieve high performance ESP is designed to provide all of these three properties simultaneously. ESP provides a comprehensive set of features to support development of compact and modular programs. The ESP compiler compiles the programs into two targets - a C file that can be used to generate efficient firmware For the device;and a specification that can be used by a verifier like SPIN to extensively test the firmware. As a case study, we reimplemented VMMC firmware that;runs on Myrinet network interface cards using ESP. We found that ESP simplifies the task of programming with event-driven state machines. It required an order of magnitude fewer lines of code than the previous implementation. We also found that model-checking verifiers like SPIN can be used to effectively debug the firmware. Finally. our measurements indicate that, the performance overhead of using ESP is relatively small.
We present a new method for automatically providing feedback for introductory programming problems. In order to use this method, we need a reference implementation of the assignment, and an error model consisting of p...
详细信息
ISBN:
(纸本)9781450320146
We present a new method for automatically providing feedback for introductory programming problems. In order to use this method, we need a reference implementation of the assignment, and an error model consisting of potential corrections to errors that students might make. Using this information, the system automatically derives minimal corrections to student's incorrect solutions, providing them with a measure of exactly how incorrect a given solution was, as well as feedback about what they did wrong. We introduce a simple language for describing error models in terms of correction rules, and formally define a rule-directed translation strategy that reduces the problem of finding minimal corrections in an incorrect program to the problem of synthesizing a correct program from a sketch. We have evaluated our system on thousands of real student attempts obtained from the Introduction to programming course at MIT (6.00) and MITx (6.00x). Our results show that relatively simple error models can correct on average 64% of all incorrect submissions in our benchmark set.
Many program analyses can be reduced to graph reachability problems involving a limited form of context-free language reachability called Dyck-CFL reachability. We show a new reduction from Dyck-CFL reachability to se...
详细信息
Many program analyses can be reduced to graph reachability problems involving a limited form of context-free language reachability called Dyck-CFL reachability. We show a new reduction from Dyck-CFL reachability to set constraints that can be used in practice to solve these problems. Our reduction is much simpler than the general reduction from context-free language reachability to set constraints. We have implemented our reduction on top of a set constraints toolkit and tested its performance on a substantial polymorphic flow analysis application.
We propose an aspect-oriented programming (AOP) language called Aspectual Caml based on a strongly-typed functional language Objective Caml with two AOP mechanisms similar to those in AspectJ language. This paper desc...
详细信息
ISBN:
(纸本)9781595930644
We propose an aspect-oriented programming (AOP) language called Aspectual Caml based on a strongly-typed functional language Objective Caml with two AOP mechanisms similar to those in AspectJ language. This paper describes the design and implementation issues of those AOP mechanisms that give us insights into the interaction between AOP features and common features in strongly-typed functional languages such as type inference, polymorphic types and curried functions. We implemented a prototype compiler of the language and used the language for separating crosscutting concerns in application programs, including for separating descriptions of a type system from compiler descriptions.
Most:programminglanguages use static scope rules for associating uses of identifiers with their declarations. Static scope helps catch errors at compile time, and it can be implemented efficiently. Some popular langu...
详细信息
ISBN:
(纸本)9781581134148
Most:programminglanguages use static scope rules for associating uses of identifiers with their declarations. Static scope helps catch errors at compile time, and it can be implemented efficiently. Some popular languages - Perl, Tcl, TeX, and Postscript - offer dynamic scope, because dynamic scope works well for variables that "customize" the execution environment, for example. Programmers must simulate dynamic scope to implement this kind of usage in statically scoped languages. This paper describes the design and implementation of imperative language constructs for introducing and referencing dynamically scoped variables-dynamic variables for short. The design is a minimalist one, because dynamic variables are best used sparingly, much like exceptions. The facility does, however, cater to the typical uses for dynamic scope, and it provides a cleaner mechanism for so-called thread-local variables. A particularly simple implementation suffices for languages without exception handling. For languages with exception handling, a more efficient implementation builds on existing compiler infrastructure. Exception handling can be viewed as a control construct with dynamic scope. Likewise, dynamic variables are a data construct with dynamic scope.
programming efficient asynchronous systems is challenging because it can often be hard to express the design declaratively, or to defend against data races and interleaving-dependent assertion violations. Previous wor...
详细信息
We address the problem of synthesizing code completions for programs using APIs. Given a program with holes, we synthesize completions for holes with the most likely sequences of method calls. Our main idea is to redu...
详细信息
ISBN:
(纸本)9781450327848
We address the problem of synthesizing code completions for programs using APIs. Given a program with holes, we synthesize completions for holes with the most likely sequences of method calls. Our main idea is to reduce the problem of code completion to a natural-language processing problem of predicting probabilities of sentences. We design a simple and scalable static analysis that extracts sequences of method calls from a large codebase, and index these into a statistical language model. We then employ the language model to find the highest ranked sentences, and use them to synthesize a code completion. Our approach is able to synthesize sequences of calls across multiple objects together with their arguments. Experiments show that our approach is fast and effective. Virtually all computed completions typecheck, and the desired completion appears in the top 3 results in 90% of the cases.
暂无评论