On 23/06/10 06:54, Christopher Done wrote:
I'm not sure how Alternative differs from MonadPlus, other than being
defined for Applicative rather than Monad. They have the same laws
(identity and associativity).
Importantly, MonadPlus must satisfy some laws for (=) and (),
whereas
Hey everyone,
Could someone explain to me (or point me to a reference explaining) the
purpose of the some and many methods of the Alternative class?
Also, there is a link posted in the documentation for
Control.Applicative to a paper which describes the motivation behind the
Applicative
I'm not sure how Alternative differs from MonadPlus, other than being
defined for Applicative rather than Monad. They have the same laws
(identity and associativity).
Some and many are probably motivated by their usefulness in
parsers. Hence optional, etc. I'm sure there are plenty of other
