Computers as Components, 2nd Edition

3.7 Design Example: Data Compressor 145

If, on the other hand, we did not care about the ability to run multiple com-

pressions simultaneously, we can make the functions a little more readable by using

global variables for the class variables:

static data_buffer buffer;

static int current_bit;

static sym_table table;

We have used the C static declaration to ensure that these globals are not defined

outside the file in which they are defined; this gives us a little added modularity. We

would, of course, have to update the specification so that it makes clear that only

one compressor object can be running at a time. The functions that implement the

methods