-$Id: README,v 1.4 2002-10-29 10:15:58 mike Exp $
+$Id: README,v 1.15 2002-11-06 20:13:45 mike Exp $
-cql-java -- a free CQL compiler for Java
+cql-java - a free CQL compiler, and other CQL tools, 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).
+INTRODUCTION
+------------
+
+cql-java is a Free Software project that provides:
+
+* A set of classes for representing a CQL parse tree (a base CQLNode
+ class, CQLBooleanNode and its subclasses, CQLTermNode, etc.)
+* A CQLCompiler class (and its lexer) which builds a parse tree given
+ a CQL query as input.
+* 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)
+* 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
But if you didn't know that, why are you even reading this? :-)
+What's what in this distribution?
+
+ README This file
+ VERSION The version-number of this distribution
+ src Source-code for the cql-java library
+ lib The compiled library file, "cql-java.jar"
+ bin Simple shell-scripts to invoke the test-harnesses
+ docs Documentation automatically generated by "javadoc"
+ test Various testing and sanity-checking frameworks
+ 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.
+
+
SYNOPSIS
--------
-Test-harness:
+Using the test-harnesses:
- $ echo "foo and (bar or baz)" | java org.z3950.zing.cql.CQLParser
+ $ CQLParser '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
-Library:
+Using the library in your own applications:
import org.z3950.zing.cql.*
// Building a parse-tree by hand
- CQLNode n1 = new CQLTermNode("dc.author", "=", "kernighan");
- CQLNode n2 = new CQLTermNode("dc.title", "all", "elements style");
+ CQLNode n1 = new CQLTermNode("dc.author", new CQLRelation("="),
+ "kernighan");
+ CQLNode n2 = new CQLTermNode("dc.title", new CQLRelation("all"),
+ "elements style");
CQLNode root = new CQLAndNode(n1, n2);
- System.out.println(root.toXCQL(3));
+ System.out.println(root.toXCQL(0));
// Parsing a CQL query
CQLParser parser = new CQLParser();
CQLNode root = parser.parse("title=dinosaur");
- System.out.println(root.toXCQL(0));
+ 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
-----------
-Se the automatically generated class documentation in the "doc"
-subdirectory. (### It's not there yet, of course)
+See the automatically generated class documentation in the "doc"
+subdirectory.
AUTHOR
------
-Mike Taylor <mike@z3950.org>
-http://www.miketaylor.org.uk
+All code and documentation by Mike Taylor <mike@z3950.org>
+ http://www.miketaylor.org.uk
+Please email me with bug-reports, wishlist items, patches, deployment
+stories and, of course, large cash donations.
LICENCE
-------
-This software is open source, but I've not yet decided exactly what
+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.
+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.
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.
+All the other free CQL compilers everyone's going to write :-)
+
+THINGS TO DO
+------------
-TO DO
------
+* ### 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.
-### Finish the parser:
-### * multi-character relations DONE but ### single "<" fails!
-### * word relations
-### * relation modifiers
-### * proximity,
+* Write javadoc comments for CQLRelation and ModifierSet.
-### Finish the CXQL-rendering back end (mostly a matter of quoting
- characters to be emitted as part of an XML document).
- DONE
+* Write "overview" file for the javadoc documentation.
-### Finish CQL-decompiling back end (mostly a matter of quoting)
+* Allow keywords to be used unquoted as search terms.
-### Write PQN-generating back end (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.)
+* 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 stochastic query generator, driven off MA grammar.
+* 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.
-### Write "javadoc" comments.
+* 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