Hi. Help me to solve the problem I faced with. I'm trying to delete items from the AVL tree 'itree' that are between 0 and 2. But as you can see the result tree contains value of 1.
import Data.Tree.AVL import Data.COrdering
mydelete' :: (Ord a) => a -> a -> AVL a -> AVL a mydelete' p1 p2 tree = let res = delete cmp tree in case contains res cmp of True -> mydelete' p1 p2 res otherwise -> res where cmp = between p1 p2
between a b x = if x < a then LT else if x > b then GT else EQ
itree = push ((sndByCC compare) 3) 3 (pair 1 2) idel = mydelete' 0 2
*Main> idel itree P (Z E 1 E) 3 E *Main> idel $ idel itree P (Z E 1 E) 3 E *Main> Explain me why I got following results and where I made error. *Main> (mydelete' 0 3) itree E *Main> (mydelete' 0 2) itree P (Z E 1 E) 3 E *Main> (mydelete' 1 2) itree P (Z E 1 E) 3 E *Main> (mydelete' 1 1) itree Z (Z E 1 E) 2 (Z E 3 E) *Main> (mydelete' 2 1) itree Z (Z E 1 E) 2 (Z E 3 E) *Main> (mydelete' 0 1) itree Z (Z E 1 E) 2 (Z E 3 E) *Main> (mydelete' 0 2) itree P (Z E 1 E) 3 E *Main> (mydelete' (-1) 2) itree P (Z E 1 E) 3 E Alexander