Ruby implements Range of T Abstract data type

Ruby implements Range of T ADT in its Range class. Elements of carrier set are represented in Range instances by recording internally type, start, and end values of range, along with an indication of whether range is exclusive or inclusive. Ruby implements all the operations above, returning nil when ADT operations are undefined. It's quite easy to see how to implement these operations given representation elements of the carrier set. Additionally Range class provides operations for accessing begin and end values defining the range that are easily accessible as they are recorded. Ultimately, Range class has an include?()operation which tests range membership by stepping through the values of the range from start value to end value when range is non-numeric. This gives slightly different results from cover?()in some cases (such as with String instances).