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Programming of Data Structures BEYOND APL

IP.com Disclosure Number: IPCOM000128549D
Original Publication Date: 1978-Dec-31
Included in the Prior Art Database: 2005-Sep-16
Document File: 11 page(s) / 36K

Publishing Venue

Software Patent Institute

Related People

Helmut K. Berg: AUTHOR [+3]

Abstract

This report describes the capabilities of a general-purpose, high-level programming language, BEYOND APL, for the programming of data structures. BEYOND APL is a compiler language into which the most valuable features of APL are carried over, yet which remedies the shortcomings of APL. The extension of the .APL information structure by the introduction of a data type IDENTIFIER, of data type and structure type declarations, and of a specific structure type LIST is the basis of a unique generalized approach to the programming of arbitrary data structures. Requirements for the construction and manipulation of data.structures are derived through a theoretical analysis of data structures. The completeness and minimality of the BEYOND APL approach to the programming of data structures is demonstrated by appropriate examples. Keywords: HIGH-LEVEL PROGRAMMING LANGUAGE, APL, DATA STRUCTURE TYPES, ORDERED SETS, DATA MODEL, DATA STRUCTURE IMPLEMENTATION, DATA STRUCTURE MANI PULATION, PARALLEL PROCESSING ' 1

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THIS DOCUMENT IS AN APPROXIMATE REPRESENTATION OF THE ORIGINAL.

Programming of Data Structures BEYOND APL

by Helmut K. Berg

Computer Science Department

114 Lind Hall Institute of Technology University of Minnesota Minneapolis, Minnesota 55455 Technical .Report 78-2 January 1978 Cover design courtesy of Ruth and Jay Leavitt Programming of Data Structures BEYOND APL

by

Helmut K. Berg

Department of Computer Science University of Minnesota

Abstract

This report describes the capabilities of a general-purpose, high-level programming language, BEYOND APL, for the programming of data structures. BEYOND APL is a compiler language into which the most valuable features of APL are carried over, yet which remedies the shortcomings of APL. The extension of the .APL information structure by the introduction of a data type IDENTIFIER, of data type and structure type declarations, and of a specific structure type LIST is the basis of a unique generalized approach to the programming of arbitrary data structures. Requirements for the construction and manipulation of data.structures are derived through a theoretical analysis of data structures. The completeness and minimality of the BEYOND APL approach to the programming of data structures is demonstrated by appropriate examples. Keywords: HIGH-LEVEL PROGRAMMING LANGUAGE, APL, DATA STRUCTURE TYPES, ORDERED SETS, DATA MODEL, DATA STRUCTURE IMPLEMENTATION, DATA STRUCTURE MANI PULATION, PARALLEL PROCESSING ' 1

1. Introduction

Although control structures and procedure concepts of high-level pro- gramming languages have become well-understood topics, the programming of data structures in general-purpose programming languages still raises some problems. In real-world computations we find always structuring relationships between the data of a program which constitute the basis for data retrieval ,. and processing. Such structuring relations usually define regular and homogeneous array-type structures in scientific applications, whereas irregular or inhomogeneous structures are inherent in applications such as data base management systems. Hence, it should be expected that such structure types exist as primitive data entities in general-purpose, high- . level programming languages. In our opinion, a structured data entity is only a primitive data entity, if the language provides an adequate set of operators on the appropriate type of data structure. Obviously, languages such as FORTRAN or ALGOL 60 are lacking such capabilities. The definitions of the type "structure" in ALGOL 68 or of the "structured data types" in PASCAL are certainly an improvement, but not a general solution to the addressed problem. The

University of Minnesota Page 1 Dec 31, 1978

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Programming of Data Structures BEYOND APL

deficiency of such languages in processing structured data entities is primarily due to the fact that they are modeled after the 30 year old concept of the von Neumann computer which defines machine variabl...