in reply to "a bit of sugar "(HOP)

Your program will run equally well if you replace 
return Iterator {

[download]
by 
return sub {

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but then you are missing a clue that you have written an iterator-like sub.

CountZero

A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James

In Section Seekers of Perl Wisdom