-$Id: README,v 1.13 2002-11-05 17:20:30 mike Exp $
+$Id: README,v 1.21 2002-11-20 09:49:28 mike Exp $
cql-java - a free CQL compiler, and other CQL tools, for Java
* A selection of compiler back-ends to render out the parse tree as:
* XCQL (the standard XML representation)
* CQL (i.e. decompiling the parse-tree)
- * PQF (Yaz-style Prefix Query Format) [### NOT YET]
+ * PQF (Yaz-style Prefix Query Format)
* A random query generator, useful for testing.
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
+Generation). The official specification is at
+ http://www.loc.gov/z3950/agency/zing/cql/cql-syntax.html
+and there's more (and friendlier) 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)
+which is supposed to be easier to parse. The specification is at
+ http://www.loc.gov/z3950/agency/zing/cql/xcql.html
+and includes an XML Schema.
But if you didn't know that, why are you even reading this? :-)
etc Other files: CQL Grammar, generator properties, etc.
"Installation" of this package would consist of putting the bin
-directory on your PATH and the lib directory on your CLASSPATH.
+directory on your PATH and lib/cql-java.jar on your CLASSPATH.
SYNOPSIS
Using the test-harnesses:
$ CQLParser 'title=foo and author=(bar or baz)'
+ $ CQLParser -c 'title=foo and author=(bar or baz)'
+ $ CQLParser -p /etc/pqf.properties 'title=foo and author=(bar or baz)'
$ CQLLexer 'title=foo and author=(bar or baz)'
(not very interesting unless you're debugging)
$ CQLGenerator etc/generate.properties seed 18
CQLNode root = parser.parse("title=dinosaur");
System.out.print(root.toXCQL(0));
System.out.println(root.toCQL());
- System.out.println(root.toPQF(qualSet));
- // ... where `qualSet' specifies CQL-qualfier => Z-attr mapping
+ System.out.println(root.toPQF(config));
+ // ... where `config' specifies CQL-qualfier => Z-attr mapping
DESCRIPTION
-----------
See the automatically generated class documentation in the "doc"
-subdirectory. (It's not all there yet, but it's coming.)
+subdirectory.
AUTHOR
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. For what it's worth, I think the
-most likely licence is the LGPL (GNU's Lesser General Public Licence)
-which lets you deploy cql-java as a part of a non-free larger work.
+The cql-java suite is Free Software, which is pretty much legally
+equivalent -- though not morally equivalent -- to Open Source. See
+ http://www.gnu.org/philosophy/free-software-for-freedom.html
+for a detailed if somewhat one-sided discussion of the differences,
+and particularly of why Free Software is an important idea.
+
+cql-java is distributed under version 2.1 of the LGPL (GNU LESSER
+GENERAL PUBLIC LICENSE). A copy of the licence is included in this
+distribution, as the file LGPL-2.1. This licence does not allow you
+to restrict the freedom of others to use derived versions of cql-java
+(i.e. you must share your enhancements), but does let you deploy
+cql-java as a part of a non-free larger work.
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 :-)
-
-
-THINGS TO DO
-------------
-
-* ### Make necessary parts of CQLNode etc. public.
-
-* ### Fix bug where "9x" is parsed as two tokens, a TT_NUMBER followed
- by a TT_WORD. The problem here is that I don't think it's actually
- possible to fix this without throwing out StreakTokenizer and
- rolling our own, which we absolutely _don't_ want to do.
-
-* Allow keywords to be used unquoted as search terms.
-
-* Some niceties for the cql-decompiling back-end:
- * don't emit redundant parentheses.
- * don't put spaces around relations that don't need them.
-
-* Write the PQN-generating back-end. This will need to be driven from
- a configuation file specifying how to represent the qualifiers,
- relations, relation modifiers and wildcard characters as z39.50
- attributes. I think Ray has such a thing, though perhaps not yet in
- a form sufficiently rigorous to be computer-readable.
-
-* Consider the utility of yet another back-end that translates a
- CQLNode tree into a Type-1 query tree using the JZKit data
- structures. That would be nice so that CQL could become a JZKit
- query-type; but you could achieve the same effect by generating PQN,
- and running that through JZKit's existing PQN-to-Type-1 compiler.
-
-* Many refinements to the random query generator:
- * Generate relation modifiers
- * Proximity support
- * Don't always generate qualifier/relation for terms
- * Better selection of qualifier (configurable?)
- * Better selection of terms (from a dictionary file?)
- * Introduce wildcard characters into generated terms
- * Generate multi-word terms
-
-* Write fuller "javadoc" comments.
+The "Changes" file, including the "Still to do" section.