{- Setup DO NOT CHANGE -}
{-# LANGUAGE CPP #-}
module Exercise_8_Sol_Tree (Tree, delete, insert, update) where

#ifdef Testing
import Tree (Tree, modify)
#else
import Exercise_8_Sol (Tree, modify)
#endif
{- End Setup -}

insert :: Ord a => b -> a -> Tree (a,b) -> Tree (a,b)
insert = modify . const . Just

update :: Ord a => (b -> b) -> a -> Tree (a,b) -> Tree (a,b)
update = modify . maybeMap
  where
    maybeMap _ Nothing = Nothing
    maybeMap f (Just x) = Just (f x)

delete :: Ord a => a -> Tree (a,b) -> Tree (a,b)
delete = modify (const Nothing)