6.8.1. Multi-parameter type classes¶
- MultiParamTypeClasses¶
- Implies:
- Since:
- 6.8.1 
 - Allow the definition of typeclasses with more than one parameter. 
Multi-parameter type classes are permitted, with extension
MultiParamTypeClasses. For example:
class Collection c a where
    union :: c a -> c a -> c a
    ...etc.