public package Foswiki::Iterator

public package Foswiki::Iterator

This class cannot be instantiated on its own - it is an interface specification for iterators. See for more information on the iterator pattern.

The interface only supports forward iteration. Subclasses should use this as their base class (so that $it->isa("Foswiki::Iterator") returns true), and must implement hasNext and next per the specification below.

See Foswiki::ListIterator for an example implementation.

hasNext() -> $boolean

Returns true if the iterator has more items, or false when the iterator is exhausted.

next() -> $data

Return the next data in the iteration.

The data may be any type.

The iterator object can be customised to pre- and post-process entries from the list before returning them. This is done by setting two fields in the iterator object:

  • {filter} can be defined to be a sub that filters each entry. The entry will be ignored (next() will not return it) if the filter returns false.
  • {process} can be defined to be a sub to process each entry before it is returned by next. The value returned from next is the value returned by the process function.

reset() -> $boolean

resets the iterator to the begining - returns false if it can't

ObjectMethod all() → @list

Exhaust the iterator. Return all remaining elements in the iteration as a list. The returned list should be considered to be immutable.

The default implementation simply runs the iterator to its end.

This site is powered by FoswikiCopyright © by the contributing authors. All material on this site is the property of the contributing authors.
Ideas, requests, problems regarding AustLII Communities? Send feedback
This website is using cookies. More info. That's Fine