27 Jun
2003
27 Jun
'03
11:49 a.m.
The previous "newtype Labeller a = Labeller (Int -> (Int, a))" (the result tuple is reversed within Control.Monad.State) would simply become (untested):
newtype Labeller a = State Int a
newLabel = do { n <- get; put (n + 1); return (Label n) }
runLabeller l = execState l minBound
it must be "evalState" instead of "execState"