Hi,
I have read the online postscript paper " Lazy Functional State Threads".
I think the typing (page 4)
f :: MutVar s a -> Mutvar s a
is wrong, since the definition of f is :
f v = runST ( newVar v 'thenST' \w ->
readVar w)
and since newVar is typed as:
newVar :: a -> ST s (MutVar s a)
hence v is of type a. Furthermore runST has type
runST :: (forall s. ST s a) -> a
hence f v can't have the type " MutVar s a ". If I understand well the
definition of f v ,thenST and readVar (see above) , f v must have type
a.
Thanks for any comments.
Jan
