BiIndex README

A BiIndex is a data structure which records relations between values.  Pairs
of values can be stored together in the BiIndex.  Later, all of the values
which have been stored with a particular value can be retrieved.  This can be
done for either of the values which were stored together, though the BiIndex
remembers which was the first and which the second value.

This software is Alpha (subject to interface change - see below).  I
will accept bug reports mailed to me.  Please put BiIndex in the
subject (Michael De La Rue <miked@ed.ac.uk>).  Reports with fixes
(diff -ur by preference) will get fixed, but please explain what you
are fixing and give an example.  Problems without fixes will have to
wait till I have time.

Please note: I'm not sure about the name.  I've had things like
suggested like

	String::BiIndex - doesn't seem right becuase it's for any
			values? I use it for URLs others maybe number?

and

	Search::BiIndex - maybe?  it isn't for general searching..

I'll probably change to the latter unless someone gives me a better
suggestion or reason to choose something different.

I'm not sure about the reference counting that is built in.  I think
maybe it causes needless inefficiency and a slightly difficult
interface (maybe returning references to arrays from the search
instead of associative arrays).  Perhaps two implementations are
called for?

The module is distributed under the same terms as perl.

If you use this stuff for something interesting a note would be nice.  Code
contributions to the perl or free software community would be even nicer.

	Michael De La Rue