Alternative

The Alternative typeclass provides monoid-like operations on type constructors instead of values.

Parent

The Alternative typeclass extends the Applicative typeclass and the Plus typeclass.

The Alternative typeclass do not expose any new method with respect to Applicative and Plus.

The Alternative typeclass require more laws to hold, in addition to the ones required by the Applicative and Plus typeclasses.

$alternative->apply($alternative->alt($f, $g), $x) == $alternative->alt($alternative->apply($f, $x), $alternative->apply($g, $x))

$alternative->apply($alternative->empty(), $f) == $alternative->empty()