A “break iterator” is an ICU object that exposes methods for locating
boundaries in text (e.g. word or sentence boundaries).
The PHP IntlBreakIterator serves as the base class
for all types of ICU break iterators. Where extra functionality is
available, the intl extension may expose the ICU break iterator with
suitable subclasses, such as
IntlRuleBasedBreakIterator or
IntlCodePointBreakIterator.
This class implements IteratorAggregate. Traversing an
IntlBreakIterator yields non-negative integer
values representing the successive locations of the text boundaries,
expressed as UTF-8 code units (byte) counts, taken from the beginning of
the text (which has the location 0). The keys yielded
by the iterator simply form the sequence of natural numbers
{0, 1, 2, …}.