adding new practice - on type classes

robertaarcoverde · Oct 12, 2011 · 1120bd3 · 1120bd3
1 parent 4da0421
commit 1120bd3
Showing 1 changed file with 11 additions and 0 deletions.
diff --git a/type_classes.hs b/type_classes.hs
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+{------------------------------------------------------------------------------
+ 
+Type Classes - Defining Set
+
+------------------------------------------------------------------------------}
+
+data Set a = Set [a]
+
+instance Eq a => Eq Set a where
+	Set [] == Set [] = True
+	Set (x:xs) == Set (y:ys) = x == y && (xs == ys)