[Haskell-cafe] Tree Construction

[Sjoerd Visscher]

Hi,

I think what you need is a trie. See f.e. http://hackage.haskell.org/package/list-tries

On Sep 25, 2010, at 11:54 AM, Tom Hawkins wrote:

> Hi,
> 
> Often I need to assemble a tree from things with unstructured
> hierarchical paths.  I built a function [1] to do this for ImProve.
> But does a library already exist that does this?  If not I may create
> one, as I need it for a few different libraries.
> 
> data Tree a b = Branch a [Tree a b] | Leaf a b
> 
> tree :: (Eq a, Ord a) => (b -> [a]) -> [b] -> [Tree a b]
> 
> Note, type 'a' is some sort of label, most often a string, and type
> 'b' form the leaves of the tree.  The function passed into 'tree'
> returns the hierarchical path of a leaf object.
> 
> -Tom
> 
> [1] http://hackage.haskell.org/packages/archive/improve/0.0.12/doc/html/Language-ImProve-Tree.html
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--
Sjoerd Visscher
http://w3future.com