[Haskell] [Newbie] Data structure for Dijkstra's algorithm

[ajb at spamcop.net]

G'day all.

Quoting robert dockins <robdockins at fastmail.fm>:

> This algorithm relies pretty fundamentally on mutability, which makes it
>   a less than wonderful fit for a functional language.

Right, which makes me wonder if this is the algorithm that you really want.

Does it have to be Dijkstra's algorithm?  Dynamic programming algorithms
(e.g. the Floyd-Warshall algorithm) are very easy to write in a lazy
language like Haskell, because you don't need mutability; you write
"thunks" into a dictionary data structure (which may depend on other
values in the data structure), and let the evaluation rule do the rest.

Cheers,
Andrew Bromage