$Header: /home/cvsroot/cql-java/README,v 1.1.1.1 2002-10-24 15:57:56 mike Exp $

cql-java -- a free CQL compiler for Java


This project provides a set of classes for representing a CQL parse
tree (CQLBooleanNode, CQLTermNode, etc.) and a Compiler class which
builds a parse tree given a CQL query as input.  It also provides
compiler back-ends to render out the parse tree either as XCQL or
Yaz-style Prefix Query Format (PQF).

CQL is "Common Query Language", a new query language designed under
the umbrella of the ZING initiative (Z39.59-International Next
Generation).  More information at
	http://zing.z3950.org/cql/index.html

XCQL is "XML CQL", a representation of CQL-equivalent queries in XML
which is supposed to be easier to parse.  More information at
	http://www.loc.gov/z3950/agency/zing/srwu/xcql.html
(not much more, though)

But if you didn't know that, why are you even reading this?  :-)


SYNOPSIS
--------

Test-harness:

	$ echo "foo and (bar or baz)" | java org.z3950.zing.cql.CQLParser

Library:

	import org.z3950.zing.cql.*

	CQLParser parser = new CQLParser();
	CQLNode root = parser.parse("title=dinosaur");
	print root.toXCQL();
	print root.toPQF(qualSet);
	// ... where `qualSet' specifies CQL-qualfier => Z-attr mapping


DESCRIPTION
-----------

Se the automatically generated class documentation in the "doc"
subdirectory.  (### It's not there yet, of course)


AUTHOR
------

Mike Taylor <mike@z3950.org>
http://www.miketaylor.org.uk


LICENCE
-------

This software is open source, but I've not yet decided exactly what
licence to use.  Be good.  Assume I'm going with the GPL (most
restrictive) until I say otherwise.


SEE ALSO
--------

Adam Dickmeiss's CQL compiler, written in C.
Rob Sanderson's CQL compiler, written in Python.
All the other free CQL compilers everyone's going to write.