25 Jan
2005
25 Jan
'05
9:29 a.m.
On 25 Jan 2005, at 13:20, Keean Schupke wrote:
f = getChar >>= (\a -> if a == "F" then mzero else return a)
In this case if the LHS returns "F" the LHS should not have been run... this contradicts itself, so this is a non option I guess.
Good paradox. That is what is upsetting me, too.
Acutally looking at GHC CVS libraries, there is not a definition for MonadPlus on the state or IO monads...
It's in Control.Monad.Error. Not documented though. Jules