类C解释器中语法树及函数调用的研究与实现

本文中的解释器是对C语言语法加以限定和扩展,使得语法更加简便。文中主要讨论了类C解释器中语法树的建立、符号表的建立以及函数调用的实现,并给出了实例。     

工业机器人语言解释器的设计与实现

定义了工业机器人编程语言,并设计、实现了机器人语言的解释器。解释器的主要功能是将机器人语言源程序转换成合适的中间数据结构,并对中间数据结构进行解释执行。解释器分为前端和后端,前端包括词法分析、语法分析、语义分析、中间数据结构的生成,后端包括语句解释器和插补器。词法分析借助flex工具实现,语法分析借助bison实现,并得到抽象语法树。语义分析通过对语法树的遍历完成类型检查及符号表的建立,同时生成中间数据结构。语句解释器对中间数据结构进行解释执行,并启动插补器进行插补计算。最后,对该解释器的功能进行了测试验证,符合预期要求。     

数据库过程语言解释器的设计与实现

本文主要介绍了作者参与开发数据库过程语言解释器,在解释器的设计中借鉴了Java虚拟机和.NETCLR的思想。结合作者的经验,对解释器系统的设计技术与实现方法进行了一定探讨。     

WMLScript解释器的原理与实现

阐述了WMLScript解释器在原理、体系结构及实现WMLScript解释器所要解决的关键技术。     

下一代网络CPL解释器的实现①

简化业务开发和提供是下一代网络(NGN)发展的关键,业务描述工具CPL是NGN创建业务的重要工具。研究了CPL解释器的网络功能和基本工作机制,提出了CPL解释器的设计与实现框架,并从执行效率和扩展性两个方面对CPL解释器设计进行了深入讨论,通过CPL解释器工作流程对CPL解释器的工作机制进行了进一步的说明。所提出的CPL解释器原型在下一代网络业务应用服务器的开发中得到了应用,有效支持了业务开发的简化,获得了良好的应用效果。     

高性能数控系统解释技术的研究与实现

针对高性能数控系统中解释器面临的要求,通过深入分析现有数控系统中解释器及与之交互的任务控制器的主要功能及实现方法,指出其在高速高精加工时存在的不足,在此基础上设计并实现了一种高效的NC代码解释机制;然后,对现有数控系统进行了基于STEP-NC的改造,提出了面向网络化制造STEP-NC数控系统的基本框架,并重点介绍了基于XML的STEP-NC程序解释器的设计与实现.     

计算机专业汇编语言课程教学研究

汇编语言依然是计算机类专业的核心课程,特别是本科类教育。阐述了汇编语言的特点,分析了当前汇编语言教学中存在的若干问题,针对问题提出了相关的解决思路和方法,对汇编语言的教学发展进行了展望。     

一种嵌入式数控代码解释器设计

该数控代码解释器用于一个嵌入式数控系统中央控制单元,给出了解释器的结构和各功能模块的实现,在实际的加工测试中该解释器能够适应各种工作情况.     

ECMAScript解释器的中间代码生成技术研究

论文详细介绍了在ECMAScript解释器中,中间代码生成部分的设计和实现方法。同时也简要介绍了解释器的整体结构。     

基于Selenium的Web自动化测试解释器

Selenium自动化测试工具在测试领域已经被广泛应用.使用时它需要依赖其它编译器或解释器才能执行测试.一方面让测试人员需要熟练的编程技术才能使用,另一方面让测试开发难度过高.为了降低自动化测试门槛,针对Web自动化测试设计了一种基于Selenium的解释器.首先深入剖析Selenium的测试原理,依据它测试接口的使用状况对主要的测试类构建依赖关系,然后根据Web程序的测试需求构建解释器的各个模块.参照编程人员的编码习惯和参考Python、JQuery等语法对每个模块的语法详细设计.最后设计一个具体的测试用例对解释器进行评价.实验结果表明,该解释器克服了使用Selenium门槛高的缺点,让编写的测试脚本更加简短整洁,测试性能也有明显的提高.     

Assembly language design and development for reconfigurable flexible assembly line

To improve the efficiency and controllability of our previous proposed cross-category product assembly line, we design an assembly language (A-code) to express a product's assembly process. We further develop an IDE to describe assembly processes as statements, which are organized according to predefined syntax as an A-code file. The interpreter translates statements into executable low-level commands. In addition, a four-layer architecture of the A-code assembly system (ACAS) is proposed to implement this language, thus an A-code files can be run on the assembly line physically. The proposed ACAS can reconfigure each unit for specific products, and control their assembly processes. The expressivity of this language is validated in two assembly cases, a simple shuttle valve and a complex relief valve. The functionality and feasibility of this system are tested by assembling 50 relief valves. The results demonstrate our ACAS can perform complex assembly tasks in a more efficient way.     

Deriving a compiler from an operational semantics written in VDL

This paper addresses the issue of compiler correctness. The approach taken is to systematically construct a correct compiler for a language from a formal semantic definition of the language. For this purpose, an operational semantics of a language is chosen as the basis for the approach. That is, the compiler for a language is derived from an interpreter of the language. The derivation process uses the notion of mixed computation proposed by Ershov. Briefly stated, one begins interpreting and when a primitive state changing instruction is about to be executed, the instruction is emitted as code instead. The correctness of all compilers produced by the method is guaranteed by proving the derivation rules correct. This proof is a one-time task for each specification language. The specification language studied in this paper is the Vienna Definition Language (VDL). The object code generated by the compiler is in an intermediate language close to an assembly language. Therefore, the translation from the intermediate language into the assembly language should be straightforward.     

基于ActiveX Scripting组件的语言解释器实现

ActiveX Scripting技术可使软件扩充变得简单,提高其可重用性.介绍了基于组件的ActiveX Scripting结构,分析了语言解释器程序的基本原理,并给出了程序的具体实现.实验测试表明,该解释器工作良好.     

Optimized H.264 compression of sign language video

In TV broadcasting deaf people are not able to get information from the audio content. In public television, some programs may be accompanied by a sign language interpreter as a part of the broadcasted signal. As a supplementary service, it would enable more programs to be accessible with a sign language interpreter to assist in comprehension. To be able to transmit such data flow separately, we define the parameters of compression of sign language interpreter image to ensure intelligibility and quality while maintaining low bitrate. This paper deals with specific video compression of Czech sign language interpreter based on regions of interest implemented to the ×264 open source library. The results of this approach are verified in subjective tests with the deaf and hearing evaluators. The experiments examine the intelligibility of sign language expressions containing minimal pairs for different levels of image compression and also evaluate the subjective quality of the final image.     

面向过程的编译和解释环境在工控组态软件系统中的应用

本文分析了开放式工控组态软件系统的优势和不足,介绍了自定义的Child-C语言编译和解释系统。使用该系统可以较大地增强组态软件系统在流程控制和应急处理方面的能力。同时还引进了事件的概念。文章重点介绍了在解释执行环境中处理二进制可执行代码的一种有效方案。     

The cost of a generated parser

The ‘fact’ that compilers employing generated parsers suffer significant performance degradation dis-a-vis recursive descent compilers is entrenched in the folklore of computing. We give detailed measurements that support this belief when the entire compiler is written in Pascal. We then define a general interface for a parsing module that hides significantly more information than usual, simplifying the process of generation and integration. This interface makes an assembly-coded parse table interpreter feasible without changing the language used for the remainder of the compiler. When the parse table interpreter is written in assembly language, the costs of the generated parser are essentially the same as those for recursive descent. (A minor space/time trade-off is possible, with the recursive descent implementation being slightly bigger and slightly faster.)     

A mechanically verified language implementation

This paper briefly describes a programming language, its implementation on a microprocessor via a compiler and link-assembler, and the mechanically checked proof of the correctness of the implementation. The programming language, called Piton, is a high-level assembly language designed for verified applications and as the target language for high-level language compilers. It provides executeonly programs, recursive subroutine call and return, stack based parameter passing, local variables, global variables and arrays, a user-visible stack for intermediate results, and seven abstract data types including integers, data addresses, program addresses and subroutine names. Piton is formally specified by an interpreter written for it in the computational logic of Boyer and Moore. Piton has been implemented on the FM8502, a general purpose microprocessor whose gate-level design has been mechanically proved to implement its machine code interpreter. The FM8502 implementation of Piton is via a function in the Boyer-Moore logic which maps a Piton initial state into an FM8502 binary core image. The compiler and link-assembler are both defined as functions in the logic. The implementation requires approximately 36K bytes and 1400 lines of prettyprinted source code in the Pure Lisp-like syntax of the logic. The implementation has been mechanically proved correct. In particular, if a Piton state can be run to completion without error, then the final values of all the global data structures can be ascertained from an inspection of an FM8502 core image obtained by running the core image produced by the compiler and link-assembler. Thus, verified Piton programs running on FM8502 can be thought of as having been verified down to the gate level.This work was supported in part by the Defense Advanced Research Projects Agency under DARPA Orders 6082 and 9151, contract MDA904-87-C-H009.     

The heart of IGES

This paper describes the problems and complexity of implementing an interpreter for IGES. IGES (the Initial Graphics Exchange Standard) is an attempt to define a language that can specify geometrical, electrical and mechanical specifications with a uniform syntax. The syntax of IGES is sketched first. This is followed by a short review of the primitives available within IGES. The interior of the interpreter is presented next with particular attention paid to the implementation of the macro language residing inside of IGES.