Generic Types

Abstract

In Chapter 11 we discussed the advantages of implementing object classes using opaque abstract data types. One of the advantages was the reusability of code. A useful feature in a language would be to introduce a higher hierarchical concept than the modules and procedures we have seen so far in Modula-2, where the same code for say, a QUEUE, can be used to implement queues of REAL values, INTEGER values, CHAR values or some other ADT values. Similarly, in sorting REAL values, INTEGER values, CHAR values or some other ADT values it would be nice to write the sort code only once.