23 Jun
2015
23 Jun
'15
4:33 p.m.
FYI, Data.Map uses an Ord instance for keys, not an Eq instance.
On Tue, Jun 23, 2015 at 1:15 PM Imants Cekusins
alter its Eq => definition
module MatchTuple (MyP) where
data MyP t = MyP(t,t) deriving Show instance Eq t => Eq (MyP t) where (==) = match
match::Eq t => MyP t-> MyP t -> Bool match (MyP(x1,x2)) (MyP(x3,x4)) | x1 == x3 && x2 == x4 = True | x1 == x4 && x2 == x3 = True | otherwise = False
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