Re: [Haskell-cafe] lists of arbitrary depth

2010/7/13 Ivan Lazar Miljenovic :

vadali writes:

...

hello, iam really new to haskell,

i want to define a function which takes as a parameter a list which can contain other lists, eg. [1,[2,3],[4,[5,6]]]

how would i define a function that can iterate through the items so (in this example) iter1 = 1 iter2 = [2,3] iter3 = [4,[5,6]]

?

( can i do that without using the Tree data type? )

Well, that's what a tree is, so why not use a tree?

Your only other option is to define your own tree-like structure:

data MyTree a = Value a | SubTree [MyTree a]

Defining your own tree structure is better in this case as Data.Tree store elements in each node, not just in the leaves. Cheers, Thu