摘要:

AbstractWe describe a program for the display and exploration of complex, domain‐specific information: ytracc, an interactive grammar debugging tool for compiler writers. The ytracc system provides the designer of a yacc grammar a method of tracing a parser as it uses the grammar, ytracc captures the states of the parse as it is carried out. The captured parse can then be replayed forwards or backwards, step‐by‐step, or subtree‐by‐subtree, as defined by the non‐terminals of the grammar. The tool has been successfully used by students as an assistant in an advanced undergraduate compiler construction class, and we use the tool in our ev

ISSN:0038-0644    

DOI:10.1002/spe.4380210202

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractThis paper describes an intelligent computerized tool designed to aid managers of software development projects in planning, managing and controlling the development process of medium‐ to large‐scale software projects. Systems dynamics is used to model and simulate the dynamic process of software development. The software development process is affected by some imprecise and vague variables that are treated as fuzzy variables. The simulation model is integrated with two expert systems. The fuzzy input variables to the system dynamics simulation model are handled by an input expert system having fuzzy logic. This expert system is designed to check the consistency of input variables. The simulation results are analysed by an output expert system having fuzzy logic. This expert system is designed to make recommendations based on experimentation with the simulation mo

ISSN:0038-0644    

DOI:10.1002/spe.4380210203

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractThe method used to save and restore the values of registers across function calls can affect performance and influence the design of specific instructions. This paper describes the results of an experiment that empirically evaluated six different schemes for saving and restoring registers on CISC machines. The methods do not require special hardware or interprocedural analysis to be performed. The six schemes were logically divided into two classes. Three of the techniques do not require the compiler to perform data‐flow analysis, whereas the other three schemes do. Within each class one scheme delegates the responsibility of preserving the state of the registers to the calling function. The second scheme of each class delegates the responsibility of saving the registers to the function being called. In the third scheme of the two classes, the registers are partitioned into two disjoint sets. The calling function is responsible for preserving register values in one of the sets whereas the called function is responsible for the other set. For each class the third scheme is shown to produce the most effective cod

ISSN:0038-0644    

DOI:10.1002/spe.4380210204

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractNumerous engineering application systems have been developed over the past twenty years, and many of these applications will continue to be used for many years to come. Examples of such applications include CAD Systems, finite‐element analysis packages and inspection systems. Because many of these applications were developed before graphical workstations became available, they often have simple command‐line user interfaces. Thus, there is a need for a graphical user interface management system (UIMS) that can be used to build point‐and‐click style interfaces for these existing engineering applications.In this paper we describe such a UIMS, and discuss its implementation using an object‐oriented database tool. This UIMS allows users to create and modify user interfaces by editing graphical representations of the interfaces, thus eliminating the need to write code to build or modify an interface. The UIMS is implemented using an object‐oriented database tool to take advantage of the data manipulation and storage management capabilities it provides. This approach reduces both the quantity and complexity of the code needed to implement the UIMS. It also allowed the UIMS to be implemented in a minimal amo

ISSN:0038-0644    

DOI:10.1002/spe.4380210205

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractProgramming environments for interactive graphics software typically have a multiplicity of tools and applications. Many of these programs contain ad hoc ‘little language’ interpreters1that do many similar things in needlessly different ways. In particular, many little languages have, in addition to their special‐purpose constructs, vestigial support for ordinary programming, such as variables, loops and conditionals. If a single, standard programming language were the basis for all these little languages, they could have complete, coherent programming semantics; they could communicate with each other more easily; no design work for basic constructs would be needed; and interpreter implementation work would be saved. The approach of reusing and extending the same core language and interpreter for a variety of little languages is theextension languageapproach.Scheme is proposed as a good choice for such a core language. Scheme is a simple, elegant, high‐level programming language. Extendable implementations are readily available in C source form. Example applications in Scheme from interactive graphics are presented that would be nearly impossible to code in a typical scripting language and very tedious to code in a lower‐level implementation language

ISSN:0038-0644    

DOI:10.1002/spe.4380210206

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractThis paper describes a novel approach to event‐based debugging. The approach is based on a (coarsegrained) dataflow view of events: a high‐level event is recognized when an appropriate combination of lower‐level events on which it depends has occurred. Event recognition is controlled using familiar programming language constructs. This approach is more flexible and powerful than current ones. It allows arbitrary debugger language commands to be executed when attempting to form higher‐level events. It also allows users to specify event recognition in much the same way that they write programs.This paper also describes a prototype, Dalek, that employs the dataflow approach for debugging sequential programs. Dalek demonstrates the feasibility and attractiveness of the dataflow approach. One important motivation for this work is that current sequential debugging tools are inadequate. Dalek contributes toward remedying such inadequacies by providing events and a powerful debugging language. Generalizing the dataflow approach so that it can aid in the debugging of concurrent programs is under invest

ISSN:0038-0644    

DOI:10.1002/spe.4380210207

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractThe unification of two patterns both containing variables is a ubiquitous operation in logic programming and in many artificial intelligence applications. Thus, many texts present unification algorithms. Unfortunately, at least seven of these presentations are incorrect. The common error occurs when logic variables are represented as binding lists; implementations that destructively update variable cells do not manifest the error. This note gives the examples that uncover the error and presents a correction.

ISSN:0038-0644    

DOI:10.1002/spe.4380210208

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

ISSN:0038-0644    

DOI:10.1002/spe.4380210201

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY