Re: [Haskell-cafe] Compiling an extremely large Haskell file (in GHC)

Hi, On Wednesday 29 June 2005 10:05, Duncan Coutts wrote:

On Tue, 2005-06-28 at 12:11 +0300, Radu Grigore wrote:

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On 6/27/05, Arjun Guha wrote:

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It's the all-pairs shortest paths data for a map of the Hyde Park area of Chicago (no real reason, really).

I wonder: is there really no way to do Floyd-Warshall in Haskell?

Indeed I understand from a colleague who implemented an all-pairs shortest paths algorithm in Haskell over the weekend for a map of the Hyde Park area of Chicago (no real reason, really!), that it takes about 0.1 seconds to execute (if you compile with -O), which is well within the 5 second limit...

you can just use dijkstra from the fgl (http://www.haskell.org/ghc/docs/latest/html/libraries/fgl/Data.Graph.Inducti...) for the paths you are interested. We used it *a lot* and we didn't have any performance problems. There is really no need to precompute all-pairs shortest path! Cheers, Stefan -- Stefan Wehr Web: http://www.stefanwehr.de PGP: Key is available from pgp.mit.edu, ID 0B9F5CE4