摘要:

AbstractIn recent years interest in coroutines has increased considerably and their usefulness is no longer in question. This paper describes a simple coroutine mechanism that fits neatly into the philosophy of the BCPL language. A few diverse applications of the mechanism are presented at the end.

ISSN:0038-0644    

DOI:10.1002/spe.4380101002

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractThis paper describes an extension of Pascal by coroutines as a basic tool to make quasi‐parallel programming possible. This extension is acheived by predefined procedures, i.e. by semantical means without modification of the syntax of the language. Process and simulation concepts are developed entirely in the extended Pascal. These concepts are suited for quasi‐parallel programming and for process‐oriented simulation of discrete‐event systems. The presented simulation system is easy to implement, it is flexible and modifiable. It retains the powerful facilities and the portability and availability of

ISSN:0038-0644    

DOI:10.1002/spe.4380101003

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractA COBOL preprocessor to implement Michael Jackson's program design language, Schematic Logic, has been written and used in the Computation Department at UMIST. This paper investigates the problems inherent in using preprocessors of this type and details the advantages which accrue from the preprocessor when teaching and using the Jackson Method.

ISSN:0038-0644    

DOI:10.1002/spe.4380101004

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractThe paper describes an implemented inter‐task communication scheme, and its design motivation. The scheme provides a well‐defined environment for all situations, including abnormal ones, such as misuse of its facilities. The main design goal is that users of the scheme should be able to verify their communication logic by inspection. Methods are described for reducing the complexity of communication logic to a minimum. The analogy with inter‐CPU communication is disc

ISSN:0038-0644    

DOI:10.1002/spe.4380101005

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractThe proliferation of different versions of a program complicates maintenance: a change to the common ancestor of several versions requires a change to all versions. Some software distributors publish editor command scripts to automate these changes, but extensive modifications of the software by a remote installer can invalidate the scripts. This paper describes a program that alleviates this problem by merging editor scripts and shows how it has simplified a substantial version maintenance problem.

ISSN:0038-0644    

DOI:10.1002/spe.4380101006

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractElectrostatic plotter type devices, CRT or hardcopy, are basically printers which allow the ‘paper’ movement only in one direction. As a result, the entire display file has to be created before the process of generating the display can begin. This arrangement differs significantly from theX‐Yplotters where the ‘plotting pencil’ and/or paper may be moved in any direction. An algorithm for generating a display on the electrostatic plotter type devices is described in this paper. This algorithm is based upon creating and maintaining a vector file consisting of end points of visible vectors, sorting these vectors, and then generating the plot—a strip at a time. Only the points that lie within the strip are calculated. The details of implementation and the data structure used are discussed. There is no restriction on the size of the display that can be generated; in fact, plots of size 100 in by 20 in have been produced using this algorithm. Noa‐prioriknowledge of the extent of the plot is required. The algorithm has been designed to operate in a device independent computer plotting system and has worked very satisfactorily without imposing any restrictions

ISSN:0038-0644    

DOI:10.1002/spe.4380101007

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractThe creation, manipulation and evaluation of univariate infinite power series is discussed. Unlike truncated power series, which store the firstnterms of an expansion, infinite power series create a procedure for calculating a general term, and are thus a formal representation of the entire expansion. No term is calculated until it is actually needed. All results may be saved along with the environment in which they were evaluated in order to prevent repeated calculation. Laurent expansion is used, and expansion in rational powers is allowed to expand expressions containing poles and branch points. The formulas applicable to the manipulation of these extended series forms are presented. The system is implemented in MODE‐REDUCE with infinite power series a new data type, or mode, which allows interfacing with the usual algebraic operators including substitution, differentiation, and integration. A series may also be inverted. Examples of the capabilities and use of the system are presente

ISSN:0038-0644    

DOI:10.1002/spe.4380101008

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

ISSN:0038-0644    

DOI:10.1002/spe.4380101010

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

ISSN:0038-0644    

DOI:10.1002/spe.4380101011

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY

ISSN:0038-0644    

DOI:10.1002/spe.4380101001

出版商:John Wiley&Sons, Ltd.    

年代:1980

数据来源: WILEY