places where sets are useful

[J. Shapiro]

[Pacman's revenge...]

	It seems to me that in compiler writing, the case where one has
multiple transitions on a single input character is an ideal case for sets.
This is of course only an intermediate stage, so perhaps it does not
justify a full blown set type.

	A better example is one of modal software, where one's modes are
defined by a set of their names... For you pascalions:

type
	mymodes = (insert, error, append, ...);
var
	status = set of mymodes;

begin
...
if (status * [insert, append]) <> [] then begin....
...
end
...
end.

Is much more readable and therefore less likely to get mangled in software
rewrites then is the exhaustive "if" phrasing.


Jon Shapiro