`make-range-generator``start``#!optional``end``step`procedureCreates a generator of a sequence of numbers. The sequence begins with

`start`, increases by`step`(default 1), and continues while the number is less than`end`, or forever if`end`is omitted. If both`start`and`step`are exact, it generates exact numbers; otherwise it generates inexact numbers. The exactness of`end`doesn't affect the exactness of the results.(generator->list (make-range-generator 3) 4) ⇒ (3 4 5 6) (generator->list (make-range-generator 3 8)) ⇒ (3 4 5 6 7) (generator->list (make-range-generator 3 8 2)) ⇒ (3 5 7)