[Haskell-cafe] Re: walking a directory tree efficiently

Massimiliano Gubinelli wrote:

Hi, what about avoid the use of the unfold over the tree and construct it directly (e.g. see http://hpaste.org/13919#a3)?

Nice solution!

I wonder if there is (an easy) possibility to construct the tree lazily so that output start immediately for large trees.

I think the modular approach would be that of using a fold-left enumerator that produces the list of paths and navigation operations by traversing the dir hierarchy "Depth First": data DirTraversalInfo = Path String | DirUp | DirDown I guess you know: http://okmij.org/ftp/papers/LL3-collections-talk.pdf

best, Massimiliano Gubinelli

Ciao Paolo