there's an equivalent definition of Applicative that may be a bit less intimidating: class Functor f => Applicative f where unit :: f () (**) :: f a

there's an equivalent definition of Applicative that may be a bit less intimidating: class Functor f => Applicative f where unit :: f () (**) :: f a -> f b -> f (a,b) [source - a bit CT heavy](https://stackoverflow.com/a/35013667/5534735 https://stackoverflow.com/a/35013667/5534735) (i'll be writing the second operation as `××` in some places because of HN asterisk weirdness) this gives us: - `unit`, a "template" container with a hole we can fill (by doing `fmap (const myValue) unit`, equivalent to `pure myValue`) - `fa ×× fb`, to "compose" two Applicative values. this shows how, unlike with Monads, the two computations must be "independent". for example, if IO were only an Applicative, you could do print "hello" ** print "world" but not getLine >>= \s -> print ("hello, " ++ s) (where the second computation depends on the string we got in the first one) it also nicely shows the two ways lists can be an Applicative - `fa ×× fb` can be either the Cartesian product `[(a,b) | a <- fa, b <- fb]` or `zip a b` (ZipList). (also, it's kind of like a Monoid, which is neat!)