Hello,
1) Do you really need a Monad instance for this?
Only for training purposes.
2) One possibility is just have it being (Node x _ _) = f = f x
I've already tried to do so, but i get only 1 element. Look.
I have a function fillTree that's fill this binary tree.
let a = fillTree 1 Empty
Hello,
I built binary tree with:
data Tree a = Empty
| Node a (Tree a) (Tree a)
deriving (Eq, Ord, Read, Show)
How can i make Monad type class instance for this tree? And can i make it on
not?
i try:
instance Monad Tree where
return x = Node x Empty Empty
Hello,
I have binary tree, with every leaf tuple - (k,v):
data Tree k v = EmptyTree
| Node (k, v) (Tree k v) (Tree k v)
How can i make Show Instance for (Tree Int Int) ?
I try:
instance Show (Tree k v) where
show EmptyTree = show Empty
show (Node (Int, Int) left
Hello, thank you for reply. I know that i can derive this. But i want to know
how can i make it by hand.
Thank you.
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Hello, Willem Van Lint, Thank you for help, it works.
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Hello,
I'm new in haskell. I want to use xml library
(http://hackage.haskell.org/package/xml) in my project.
I downloaded it.then try to build and install:
runhaskell Setup.hs configure
runhaskell Setup.hs build
runhaskell Setup.hs install
All ok. There are no errors. When i try import
Thank you, for reply.
Yes i use ghc.
First thing is to do 'ghc-pkg list'. If your package doesn't show up
then it's not installed, according to the package registry. 'cabal
install' should have registered it. If it is in the list, then it
depends how you're building. If you use ghc manually,
