Re: [Haskell-cafe] elem of infinite set of tuple

On Friday 16 May 2008, leledumbo wrote:

I don't know how Haskell should behave on this. Consider this function: elemOf (x,y) = (x,y) `elem` [ (a,b) | a <- [0..], b <- [0..] ]

FYI: The control-monad-omega package on hackage.haskell.org can handle this sort of thing (liberties taken with ghci formatting): Prelude> :m + Control.Monad.Omega Prelude Control.Monad.Omega> (1,1) `elem` runOmega (do x <- each [0..] ; y <- each [0..] ; return (x,y)) True Prelude Control.Monad.Omega> It does breadth-first instead of depth-first search. -- Dan