How do you get a subtype in Haskell (or any other functional language
come to that)? I'm thinking along the lines of (pseudo-notation):
type weekday = {Mon, Tue, Wed, Thur, Fri}
type weekend = {Sat, Sun}
type day = weekend + weekday
It springs to mind that this kind of problem is possibly solved by
inheritance in the class system, but that only works for pre-defined
classes. Or does it?
Maybe subtypes don't fit elegantly into the functional model. Maybe
they aren't necessary anyway.
Thoughts appreciated.
Rob
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Rob Turner, Dept. of Computer Science, University of Hull, UK.
Internet: [EMAIL PROTECTED] Phone: (0482) 465212
