ored pattern that matches dates:
<pre>
    re&#62; /\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d/
  data&#62; The date is 23ja\=ph
  Partial match: 23ja
</pre>
At this stage, an application could discard the text preceding "23ja", add on
text from the next segment, and call the matching function again. Unlike the
DFA matching function, the entire matching string must always be available,
and the complete matching process occurs for each call, so more memory and more
processing time is needed.
