[Haskell-cafe] walking a directory tree efficiently

Don Stewart dons at galois.com
Tue Jan 13 18:27:08 EST 2009

> Hi.
> During a tentative (quite unsuccessfull) to convert a simple Python 
> script that prints on stdout a directory and all its subdirectory [1] in 
> a good Haskell (mostly to start to do real practice with the language), 
> I came across this blog post:
> http://blog.moertel.com/articles/2007/03/28/directory-tree-printing-in-haskell-part-three-lazy-i-o
> Since recently I read about alternatives to lazy IO (like iteratee), I'm 
> curious to know if a flexible, efficient and safe alternative exists, 
> for the task of display a directory tree.
> [1] http://paste.pocoo.org/show/99523/

If you can do it with strict IO in Python, do the same thing in Haskell
with System.IO.Strict. It should be mechanical to translate Python
programs directly into naive IO-based Haskell using strict IO. Boring,
but mechanical.

There's no iteratee/fold-based IO system yet.

-- Don

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