[Haskell-beginners] Grappling with State Monad get
Olumide
50295 at web.de
Tue Aug 1 23:16:04 UTC 2017
Ahoy Haskellers,
In the section "Getting and Setting State"
(http://learnyouahaskell.com/for-a-few-monads-more#state) in LYH get is
defined as
get = state $ \s -> (s, s)
How does does get determine the type s, is considering that it has no
argument as per the definition given above? Or is the definition written
in some sort of point-free notation where an argument has been dropped?
I find the line stackNow <- get in the the function(?) stackyStack
confusing for the same reason. I guess my difficulty is that state $ \s
->(s , s) has a generic type (s) whereas the stackyStack has a concrete
type. Is the type of s determined from the type of the stateful
computation/do notation?
Regards,
- Olumide
More information about the Beginners
mailing list