Class Iterator

Description

This is the interface for iterator objects. They implement an interface to a collection or stream of data items and a cursor that can be used to iterate over and examine individual items in the data set.

Iterators are typically created to access a data set in some specific object, array, mapping, multiset or string. An object can have several iterators that access different data sets in it, or the same in different ways. E.g. strings have both an iterator for access char-by-char (String.Iterator), and another for access over splitted substrings (String.SplitIterator). lfun::_get_iterator may be defined in an object to get an instance of the canonical iterator type for it. It's used by e.g. foreach to iterate over objects conveniently.

It's not an error to advance an iterator past the beginning or end of the data set; _iterator_index and _iterator_value will just return UNDEFINED then. An iterator in that state need not keep track of positions, so it's undefined what happens if it's "moved back" into the set of items.

Backward movement for iterators is currently not supported.

See also

get_iterator, lfun::_get_iterator, Array.Iterator, Mapping.Iterator, Multiset.Iterator, String.Iterator, String.SplitIterator, 8.0::Iterator.

Method create

Iterator Iterator(void|mixed data)

Description

Initialize this iterator to access a data set in data. The type of data is specific to the iterator implementation. An iterator may also access some implicit data set, in which case data isn't specified at all.

The iterator initially points to before the first item in the data set, if there is any.

The iterator does not need to support being reused, so this function is typically declared protected.

Note

In the iterator API in Pike 8.0 and earlier the iterators initially pointed to the first element.

See also

CompatIterator