The Art of Assembly Language, 2nd Edition

4.4 enum and HLA Enumerated Data Types

In a previous section discussing constants and constant expressions, you saw the following example:

const          TapeDAT          :=     0;
const          Tape8mm          :=     TapeDAT + 1;
const          TapeQIC80        :=     Tape8mm + 1;
const          TapeTravan       :=     TapeQIC80 + 1;
const          TapeDLT          :=     TapeTravan + 1;

This example demonstrates how to use constant expressions to develop a set of constants that contain unique, consecutive values. There are, however, a couple of problems with this approach. First, it involves a lot of typing (and extra reading when reviewing this program). Second, it's very easy to make a mistake when creating long lists of unique constants and reuse or skip some values. The HLA enum type provides a better way to create a list of constants with ...