It seems like you would, going by semantics of System F, where types
with type variables name a certain subset of types, => constraints
further restrict the types of the same "shape" (are they an
independent kind of restriction?), so typeclass declarations
with/without => specify a partial order over types because the subset
relation is.
On Mon, Nov 14, 2011 at 3:47 AM, Patrick Browne
Is there a partial order on Haskell type classes? If so, does it induce any quasi-order relation on types named in the instances? In the example below types C and D have the same operation f Thanks, Pat
data C = C deriving Show data D = D deriving Show
class A t where f::t->t f t = t
instance A C where instance A D where
class A t => B t where
instance B C where instance B D where
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