What is the Perl version of a Python iterator?

I am learning Perl at my work and enjoying it. I usually do my work in Python but boss wants Perl.

Most of the concepts in Python and Perl match nicely: Python dictionary=Perl hash; Python tuple=Perl list; Python list=Perl array; etc.

Question: Is there a Perl version of the Python form of an Iterator / Generator?

An example: A Classic Python way to generate the Fibonacci numbers is:

#!/usr/bin/python

def fibonacci(mag):
     a, b = 0, 1
     while a<=10**mag:
         yield a
         a, b = b, a+b

for number in fibonacci(15):  
     print "%17d" % number

Iterators are also useful if you want to generate a subsection of a much larger list as needed. Perl 'lists' seem more static - more like a Python tuple. In Perl, can foreach be dynamic or is only based on a static list?

The Python form of Iterator is a form that I have gotten used to, and I do not find it documented in Perl... Other than writing this in loops or recursively or generating a huge static list, how do I (for ex) write the Fibonacci subroutine it in Perl? Is there a Perl yield that I am missing?

Specifically -- how do I write this:

#!/usr/bin/perl
use warnings; use strict; # yes -- i use those!

sub fibonacci {
   # What goes here other than returning an array or list? 
}

foreach my $number (fibonacci(15)) { print $number . "\n"; }

Thanks in advance to being kind to the newbie...