The
Ord class is used for totally ordered datatypes.
Instances of
Ord can be derived for any user-defined datatype
whose constituent types are in
Ord. The declared order of the
constructors in the data declaration determines the ordering in
derived
Ord instances. The
Ordering datatype allows a
single comparison to determine the precise ordering of two objects.
Minimal complete definition: either
compare or
<=.
Using
compare can be more efficient for complex types.