ConstructorIn3.hs.expected

module ConstructorIn3 where


--Any type/data constructor name declared in this module can be renamed.
--Any type variable can be renamed.

--Rename tyoe variable 'a' in BTree to 'b'

data BTree b = Empty | T b (BTree b) (BTree b)
               deriving Show

buildtree :: Ord a => [a] -> BTree a
buildtree [] = Empty
buildtree (x:xs) = insert x (buildtree xs)

insert :: Ord a => a -> BTree a -> BTree a
insert val Empty = T val Empty Empty
insert val tree@(T tval left right)
   | val > tval = T tval left (insert val right)
   | otherwise = T tval (insert val left) right

main :: BTree Int
main = buildtree [3,1,2]