摘要:

AbstractThe correctness of an indenting program for Pascal is proved at an intermediate level of rigour. The specifications of the program are given in the companion paper.1The program is approximately 330 lines long and consists of four modules:io, lex, stackandindent. We prove first that the individual procedures contained in these modules meet their specifications as given by the entry and exit assertions. A global proof of the main routine then establishes that the interaction between modules is such that the main routine meets the specification of the entire program. We argue that correctness proofs at the level of rigour used here serve very well to transfer one's understanding of a program to others. We believe proofs at this level should become commonplace before more formal proofs can take over to reduce traditional testing to an inconsequential place.

ISSN:0038-0644    

DOI:10.1002/spe.4380130302

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractThe design and implementation of a microcomputer network to support laboratory automation is described and discussed. It is a multi‐level hierarchical star network connected to a multiprogrammed computer on which all program development is done. The system is capable of supporting a large number of experimental setups. The microcomputers are either used as (1) local microcomputers for experiment control, (2) multiplexers for other microcomputers or (3) controllers for peripherals known in the multiprogrammed computer.The system combines the advantages of a large multiprogrammed computer with those of a small cheap dedicated computer close to the experiment.Character‐oriented peripherals are connected to the multiprogrammed computer only. This reduces the amount of system software to be written for the network by an order of magnitude and eliminates the need for interfacing to existing small computer software. The system software consist of three small programs (monitors) providing a process concept and multibuffering of data in the involved computers. The monitor establishes a hierarchy of control and they eliminate the need for any local load device for the microcomputers as their monitors are in a read‐only store.The system developed is designed for control of experiments in an environment where the experiments and the control strategies change with time and where the data refinement required is beyond what can be done on the present generation of microcomp

ISSN:0038-0644    

DOI:10.1002/spe.4380130303

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractThe performance of a throw‐away compiler for Pascal is compared with an interpreter, a threaded code compiler and a traditional compiler. In addition an evaluation is given of the performance of various strategies for dynamic and throw‐away compiling in a small worksp

ISSN:0038-0644    

DOI:10.1002/spe.4380130304

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractThe XERROR package is a collection of portable Fortran routines for processing of errors that occur in other routines. It was developed as the error‐handling package for the SLATEC Common Mathematical Library, which is currently in use at a number of U.S. Department of Energy and other facilities. This paper describes how to use the package, from the viewpoint of the writer of library routines that need to call the XERROR package to handle errors, and from the viewpoint of the user of those library routine

ISSN:0038-0644    

DOI:10.1002/spe.4380130305

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractPS‐Algol is a dialect of Algol for the programming of problems that would normally require a database management system. It supports a persistent heap, and an associative store; it has embedded within the language features to support tasks normally carried out by filing systems or database management system

ISSN:0038-0644    

DOI:10.1002/spe.4380130306

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractThe chunk manager provides simple transaction management, concurrency control and allocates, administers and retrieves apparently contiguous chunks of data of arbitrary and varying size on disc. This system is designed to permit students and research workers to rapidly assemble and test their own DBMS, supporting any data model. Currently it is being used to support PS‐Algol, an implementation of DAPLEX, a relational system and student database exercises.A chunk is similar to the common meaning of ‘record’ except that there is no implication of internal structure or consistent and static size. An efficient table processing capability is also provided.Locking and access control are implemented at the bag level to prevent conflicting use of data without excessive operating cost. The problems associated with concurrent access of shared bags have been studied and the currently implemented and future proposed solutions are disc

ISSN:0038-0644    

DOI:10.1002/spe.4380130307

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractThe programming language Pascal was designed and implemented in a non‐interactive programming environment. This paper surveys proposals for incorporating interaction into Pascal, and focuses on a scheme known as ‘lazy evaluation’. It presents and compares performance measurements of two Pascal run‐time systems for the same compiler; a buffered, non‐interactive version, and a modification of that system to support lazy e

ISSN:0038-0644    

DOI:10.1002/spe.4380130308

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

ISSN:0038-0644    

DOI:10.1002/spe.4380130301

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY