Re: [Haskell-cafe] simple state monad exercises? (besides labeling trees)

On Mon, Jul 06, 2009 at 12:54:54PM -0400, Thomas Hartman wrote:

Can someone give some simple common scenarios where the state monad is useful, besides labeling trees?

Implementing the Union-Find data structure[1] for unification based type inference. As far as I know, no good alternative exists that has the same very low computational complexity of the true stateful union-find. Also, it's computational complexity has the ackermann's function in it, which is just neat. John [1] http://en.wikipedia.org/wiki/Disjoint-set_data_structure -- John Meacham - ⑆repetae.net⑆john⑈ - http://notanumber.net/