The signature of a generic comparison function.
A comparison function represents an ordering on a type of objects. A total ordering on a type means that for two values, either they are equal or one is greater than the other (and the latter must then be smaller than the former).
A Comparator function represents such a total ordering by returning
- a negative integer if
ais smaller than
- zero if
ais equal to
- a positive integer if
ais greater than