May 26, 2018
General-purpose iterator class
This module is meant to be the definitive implementation of iterators, as popularized by Mark Jason Dominus’s lectures and recent book Higher Order Perl, Morgan Kauffman, 2005.
An “iterator” is an object, represented as a code block that generates the “next value” of a sequence, and generally implemented as a closure. When you need a value to operate on, you pull it from the iterator. If it depends on other iterators, it pulls values from them when it needs to. Iterators can be chained together see IteratorUtil for functions that help you do just that, queuing up work to be done but not actually doing it until a value is needed at the front end of the chain. At that time, one data value is pulled through the chain.
Iterator.pm provides a class that simplifies creation and use of these iterator objects. Other Iterator modules see “SEE ALSO” provide many general-purpose and special-purpose iterator functions.