An iterator class, maintaining loop state for simple enumerations of the elements of a range.
The Index class is derived from the LocBlocksIndex class (see section 7.2) which is in turn derived from Location. These classes are used extensively in Adlib code that has to deal with ranges whose level is not known in advance. Their use can be avoided if the level of the ranges is known at compile time, using code transformations described in section 7.3.
The public interface of the Index class is
class Index : public LocBlocksIndex {
public :
Index(Range x) ;
void begin() ;
void next() ;
} ;