[Haskell-beginners] Type Tree variables

[Ozgur Akgun]

(Replying to the list again)

On 11 March 2012 14:15, bahadýr altan <doaltan at yahoo.co.uk> wrote:

> Hi,
> Thanks for your reply. I tried your solution but my function becomes
>  like this and it gives an error on the right side :
>
function (Node a (Node b _ _) (Node c _ _))  = (Node c (Node a _ _) (Node b
> _ _))
>

This is not what you originally said though. If you need to refer to the
subtrees, you just need to name them. (Instead of using _)

[ not a very useful function, but still: ]

f :: Tree a -> Tree a
f (Node x (Node y y1 y2) (Node z z1 z2)) = Node x (Node y y1 y2) (Node z z1
z2)
-- also think about the types: (x, y, z :: a) (y1, y2, z1, z2 :: Tree a)


> The thing is I don't need to process the subtrees but I still have to
> return them as an output. I still can't do that. And I read a few chapters
> in LYAH, it was pretty good, I learned haskell from there. However, I think
> the answer of this question isn't in LYAH.
> Thanks..
> Bahadir
>

-- 
Ozgur Akgun
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