declaring a generic type in type synonyms
21 Feb 2002 21:06:28 +0100
"Andre W B Furtado" <firstname.lastname@example.org> writes:
> Is is possible to declare a generic type without using "data" or "newtype"?
> For example, I woud like that "pair" is a type synonym for "(t,t)" where t
> is a generic type, but just saying:
> > type pair = (t,t)
> won't work: i get a parse error.
- types in haskell must be capitalized (maybe a better syntax error message
would be nice, i ran into the same pb)
- "t" is a free variable, so you can't write this. Either write:
type Pair t = (t,t)
type Pair = (Int,Int)
type Pair t1 t2 = (t1, t2)