Language: Scheme

(define my_iterator (forAll 1 5)) (my_iterator + 0)  15 (my_iterator * 1)  120 (my_iterator (lambda (x y) (display x)(display " ")) "")  1 2 3 4 5 

The forAll procedure takes two arguments: the start and end values of a series, and returns a function (a closure, called my_iterator in the examples above). The resulting closure expects two new arguments: an operation to be applied to all elements in the series, as well as an initial value to start the operations. The operation passed to the closure (+, *, and lambda in the examples above), should expect two arguments as well: an element from the series and the running total.