EN 28631:1993

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Information technology - Program constructs and conventions for their representation (ISO/IEC 8631:1989)Informationstechnik - Programmkonstrukte und Regeln für ihre Anwendung (ISO/IEC 8631:1989)Technologies de l'information - Structures de programmes et normes pour leur représentation (ISO/IEC 8631:1989)Information technology - Program constructs and conventions for their representation (ISO/IEC 8631:1989)35.080Dokumentiranje razvoja programske opreme in sistemov (sistemska dokumentacija)Software development and system documentationICS:Ta slovenski standard je istoveten z:EN 28631:1993SIST EN 28631:1997en01-december-1997SIST EN 28631:1997SLOVENSKI
STANDARD



SIST EN 28631:1997



SIST EN 28631:1997



SIST EN 28631:1997



INTERNATIONAL STANDARD lSO/lEC 8631 Second edition 1989-08-01 Information technology - Program constructs and conventions for their representation Technologies de l’informa tion - Structures de Programmes et normes pour leur reprben ta tion Reference number ISWIEC 8631 : 1989 (E) SIST EN 28631:1997



ISO/IEC 8631 : 1989 (E) Contents Page Foreword. iii Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv 1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2 Definition of program construct . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 3 How constructs may be combined. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4 Specification of constructs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4.1 Imperative construct . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4.2 Serial construct . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4.3 Parallel construct . . 1 4.4 Iterative construct . . 1 4.5 Selective choice construct . . 1 5 Termination. . . 2 6 Definition of subsets . 2 Annex A Charting notations for program constructs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 @ ISO/IEC 1989 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronie or mechanical, including photocopying and microfilm, without Permission in writing from the publisher. ISO/IEC Copyright Office l Case postale 56 e CH-1211 Geneve 20 l Switzerland Printed in Switzerland ii SIST EN 28631:1997



ISO/IEC 8631 : 1989 (EI Foreword ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) together form a System for worldwide standardization as a whole. National bodies that are members of ISO or IEC participate in the develop- ment of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information technology, ISO and IEC have established a joint technical committee, ISOIIEC JTC 1. Draft International Standards adopted by the joint technical committee are circulated to national bodies for approval before their accep- tance as International Standards. They are approved in accordance with procedures re- quiring at least 75 % approval by the national bodies voting. International Standard ISO/IEC 8631 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology. This second edition cancels a constitutes a minor revision. nd ces the first edition (ISO 8631 : 1986), of which it Annex A of this International Standard is for information only. . . . Ill SIST EN 28631:1997



ISO/IEC 8631 : 1989 (EI Introduction It is accepted that a limited number of distinct constructs combined in a weil-defined manner is sufficient to express any process. A program is considered to be well- structured if it is built from the constructs contained in this International Standard and follows the rules of combination. A program may be viewed at several conceptual levels. At any but the lowest construct may be represented as a number of constructs at a lower Ievel. level, one SIST EN 28631:1997



INTERNATIONAL STANDARD ISO/IEC8631 : 1989 (E) Information technology - Program constructs and conventions for their representation 1 Scope This International Standard is concerned with the expression of procedure oriented algorithms. lt a) defines the nature of program constructs; b) indicates the manner in which constructs tan be combined; c) provides specifications for a set of constructs; d) permits the definition of a variety of subsets of the defined constructs. 4.2 Serial construct This construct contains two or more procedure Parts and an implicit control part which determines that the procedure Parts are to be executed exactly once in the sequence given. 4.3 Parallel construct This construct consists of two or more procedure Parts and a control part which initiates these procedure Parts. Execution of the construct is finished when all initiated procedure Parts are completely executed. 4.4 Iterative construct See annex A for symbolic representations. a) Pre-tested iteration 2 Definition of program construct A program construct consists of a set of one or more procedure Parts and a control part which may be implicit. Esch procedure part consists of one or more operations to be performed or may be null. The control part determines the manner in which the procedure Parts are to be executed. lt tan consist of a directive and a set of conditions. The control part then activates or de-activates the procedure Part(s) depending on the nature of the directive and the values of the conditions. If there is neither directive nor condition, control is called implicit. 3 How constructs may be combined The only way in which constructs tan be combined to build a weil-structured program is by replacing a procedure part of one construct by a complete construct. 4 Specification of constructs 4.1 Imperative construct This construct contains one procedure part and an implicit control part which determines that the procedure part is executed exactly once. This construct consists of a procedure part and a control part with one condition, the value of which determines whether the procedure part is executed zero or more times. b) Post-tested iteration This construct consists of a procedure part and a control part with one condition, the value of which determines whether the procedure part is executed more than once. c) Continuous iteration This construct consists of a procedure part and a control part with an implicit condition which specifies that the procedure part will be repeated indefinitely. 4.5 Selective choice construct a) Monadic selective This construct consists of a Single procedure part and a control part with one condition, the value of which determines whether or not the procedure part is to be executed. b) Dyadic selective This construct consists of two procedu
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