A base62 transformation format of ISO 10646 for multilingual identifiers

ISO 10646 Universal Character Set (UCS) is a 31‐bit coding architecture that covers symbols in most of the world's written languages. Identifiers in programming languages are usually defined by using alphanumeric characters of ASCII, which represent mainly English words. An approach for working around this deficiency is to encode multilingual identifiers into the alphanumeric range of ASCII. For case‐sensitive languages, an encoding that utilizes [0–9][A–Z][a–z] can be more space‐efficient for multilingual identifiers. This paper proposes a base62 transformation format of ISO 10646 called UTF‐62. The resulting string of UTF‐62 is within a [0–9][A–Z][a–z] range, a total of 62 base characters. UTF‐62 also preserves the lexicographic sorting order of UCS‐4. Copyright © 2001 John Wiley & Sons, Ltd.     

A residualizing semantics for the partial evaluation of functional logic programs

Recent proposals for multi-paradigm declarative programming combine the most important features of functional, logic and concurrent programming into a single framework. The operational semantics of these languages is usually based on a combination of narrowing and residuation. In this paper, we introduce a non-standard, residualizing semantics for multi-paradigm declarative programs and prove its equivalence with a standard operational semantics. Our residualizing semantics is particularly relevant within the area of program transformation where it is useful, e.g., to perform computations during partial evaluation. Thus, the proof of equivalence is a crucial result to demonstrate the correctness of (existing) partial evaluation schemes.     

Common knowledge does not have the Beth property

Common knowledge is an essential notion for coordination among agents. We show that the logic of common knowledge does not have the Beth property and thus it also lacks interpolation. The proof we present is a variant of Maksimova's proof that temporal logics with ‘the next’ do not have the Beth property. Our result also provides an explanation why it is so difficult to find ‘nice’ deductive systems for common knowledge.     

高校外语调频台自动播出系统研究

给出了一套数字式自动播出系统的方案,以及音频资源库建设的方法,同时提出工作实践中的注意事项,便于系统的推广与实现。利用计算机技术实现校园外语调频台的数字式自动播出,大大提高了播放质量和效率。     

Interpretation and code generation based on intermediate languages

The possibility of supporting high level languages through intermediate languages to be used for direct interpretation and as intermediate forms in compilers is investigated. An accomplished project in the construction of an interpreter and a code generator using one common intermediate form is evaluated. The subject is analysed in general, and a proposal for an improved design scheme is given.     

Dispel: A run-time debugging language

Dispel is a language designed to aid communication between an interactive user and a run-time, symbolic debugging system. Important attributes of Dispel are that it provides a small set of primitive debugging actions, most traditional debugging aids (such as variable traces and postmortem dumps) are written in terms of these primitives as debugging routines, and Dispel serves both as an interactive debugging command language and as a special-purpose programming language. The syntax and semantics of Dispel are explained and examples of Dispel commands and routines are presented.     

Illustrating Client and Implementation Readability Tradeoffs in Ada and C++

The relative merits of Ada and C++ have fostered numerous discussions among software developers. With the release of Ada 95 and its object-oriented features, we expect these discussions to intensify, particularly given the increasing number of features for which there are implementations in both languages. In this paper, we compare Ada and C++ based on the readability of class and client implementations. We examine this issue using a case study. Our case study illustrates a partial tradeoff that exists between the readability of a class and the readability of its clients. This tradeoff depends on the degree to which overloading is used; extensive use of overloading adds to class complexity, although it increases client readability.     

一种基于属性文法的形式描述方法

本文通过讨论软件测试自动化的基本条件和特殊要求,给出了一种基于属性文法的形式描述方法,它是对一般属性文法作以下两方面扩展得到的:(1)扩展运算函数的值域;(2)补充运算函数在条件不成立时的定义.这样的形式描述方法满足软件测试自动化对形式描述的要求.