title: Why does the Alternative typeclass need to be a sub-class of Control.Applicative
body: <p>Haskell provides a standard typeclass 'Alternative' that effectively provides the <code>&lt;|&gt;</code> operator for any type that is also an Applicative.</p>
  
  <p>As I understand it Alternative is considered a Monoid on Applicative's, however the <code>&lt;|&gt;</code> operator seems to make complete sense in a lot of types that aren't Applicative Functors as well, and there doesn't need to be any specific dependency on the Applicative typeclass for it to work properly.</p>
  
  <p>Is there a reason why Alternative needs to be a subclass of Applicative, and if so is there a standard typeclass to define similar functionality on non-applicative types?</p>