Refactoring in Tunes

Jim Little
Sat, 08 Jan 2000 22:48:00 -0700

"Brian T. Rice" wrote:

> My idea here of a type system is one specified in the manner of predicate
> logic (though not with standard predicate logic only). Subclassing in tunes
> would not be "overridding methods" and "adding variables" but specifying a
> type that obeys more specifications.

This sounds intriguing.  In particular, polymorphism seems cleaner;
rather than saying "accept any variable of this type or its subtypes"
you would say, "accept any variable whose type obeys this specification
(and that one, and that one)."  Or perhaps, "accept any variable whose
type minimally obeys all the specifications of this type."

As far as how you could refactor under this sort of type system; well, I
don't know.  My understanding of "good design" is largely intuitive,
unfortunately, and this is a new enough approach that I can't begin to
say what would be "bad design" or how you would incremently change into
a "good design."