9.0 Chapter Goals

The purpose of this chapter is to explore in some detail the concept of structured data. The array type was considered in earlier chapters; here the set and record types are introduced. On completing the chapter, the student should understand and be able to use the following:

Data Representation Abstractions


structured and unstructured data, sets, set elements, records, and record fields

Realized in the Modula-2 notation:

the Modula-2 set and record types

random Access Files

Data Manipulation Abstractions


set operations

Realized in the Modula-2 notation:

set operations, and the manipulation of record fields

reading and writing random access files

Programming Abstractions


unqualifying record field identifiers

Realized in the Modula-2 notation:

the WITH statement