From: mike <mike>
Date: Wed, 6 Nov 2002 20:13:45 +0000 (+0000)
Subject: Finish (more or less) to CQL-to-PQF translator.
X-Git-Tag: v1.5~233
X-Git-Url: http://lists.indexdata.dk/?a=commitdiff_plain;h=fc82b225d39cc66cb85c2557db0c0d4a4c5a6e27;p=cql-java-moved-to-github.git

Finish (more or less) to CQL-to-PQF translator.
Add new exceptions arising from PQF translation.
Substantially rework the PQF-translation configuration properties.
Add new javadoc comments for various classes.
Fix visibility of some methods.
---

diff --git a/Changes b/Changes
index cc072fe..884403f 100644
--- a/Changes
+++ b/Changes
@@ -1,4 +1,4 @@
-$Id: Changes,v 1.1 2002-11-06 00:05:57 mike Exp $
+$Id: Changes,v 1.2 2002-11-06 20:13:45 mike Exp $
 
 Revision history for "cql-java"
 
@@ -13,14 +13,19 @@ Revision history for "cql-java"
 	  through parse-trees and so implement its own back-end
 	  (e.g. to build BER-friendly data structures using whatever
 	  Z39.50 toolkit is preferred.)
-	- Add javadoc comments for CQLNode and subclasses.
-	- Add the toPQF(Properties p) method to CQLNode and subclasses.
-		(### NOT YET FINISHED)
-	- Add UnknownQualifierException and UnknownRelationException.
+	- Add the toPQF(Properties p) method to CQLNode and
+	  subclasses.  This produces a query in YAZ-style Prefix Query
+	  Format, which can be trivially translated into a Z39.50
+	  Type-1 query (see, for example, JZKit's code to do so).
+	- Add etc/pqf.properties to configure to toPQF() method.
 	- Add "-p <props-file>" option to the CQLParser test-harness,
 	  indicating that the parsed tree is to be rendered to PQF.
-	- Add etc/pqf.properties to configure to toPQF() method.
+	- Add PQFTranslationException and its subclasses
+	  UnknownQualifierException, UnknownRelationException,
+	  UnknownRelationModifierException and
+	  UnknownPositionException.
 	- Rename ParameterMissingException to MissingParameterException.
+	- Add javadoc comments for CQLNode and its subclasses.
 
 0.1  Sun Nov  3 20:58:27 2002
 	- First public release.
diff --git a/README b/README
index ee96d8a..a508b3d 100644
--- a/README
+++ b/README
@@ -1,4 +1,4 @@
-$Id: README,v 1.14 2002-11-06 00:05:58 mike Exp $
+$Id: README,v 1.15 2002-11-06 20:13:45 mike Exp $
 
 cql-java - a free CQL compiler, and other CQL tools, for Java
 
@@ -15,7 +15,7 @@ cql-java is a Free Software project that provides:
 * 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
@@ -73,15 +73,15 @@ Using the library in your own applications:
 	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
@@ -119,8 +119,9 @@ THINGS TO DO
   possible to fix this without throwing out StreakTokenizer and
   rolling our own, which we absolutely _don't_ want to do.
 
-* Write javadoc comments for CQLRelation, ModifierSet and the
-  Exception classes.
+* Write javadoc comments for CQLRelation and ModifierSet.
+
+* Write "overview" file for the javadoc documentation.
 
 * Allow keywords to be used unquoted as search terms.
 
@@ -128,12 +129,6 @@ THINGS TO DO
 	* 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
@@ -149,4 +144,3 @@ THINGS TO DO
 	* Introduce wildcard characters into generated terms
 	* Generate multi-word terms
 
-* Write fuller "javadoc" comments.
diff --git a/etc/pqf.properties b/etc/pqf.properties
index 4508572..875d871 100644
--- a/etc/pqf.properties
+++ b/etc/pqf.properties
@@ -1,67 +1,95 @@
-# $Id: pqf.properties,v 1.2 2002-11-06 10:37:06 mike Exp $
+# $Id: pqf.properties,v 1.3 2002-11-06 20:13:45 mike Exp $
 #
 # Propeties file to drive org.z3950.zing.cql.CQLNode's toPQF()
 # back-end.  This specifies the interpretation of various CQL
-# qualifiers in terms of Type-1 query attributes.
+# qualifiers, relations, etc. in terms of Type-1 query attributes.
 #
 # See http://www.loc.gov/z3950/agency/zing/srwu/dc-indexes.html
 # for the Maintenance Agency's work-in-progress mapping of Dublic Core
 # qualifiers to Attribute Architecture (util, XD and BIB-2)
 # attributes.
+
+# The default access point:
 #
-dc.title			= 1=4
-dc.subject			= 1=21
-dc.creator			= 1=1003
-dc.editor			= 1=1020
-dc.publisher			= 1=1018
-dc.description			= 1=62	# "abstract"
-dc.date				= 1=30
-dc.resourceType			= 1=1031	# guesswork: "Material-type"
-dc.format			= 1=1034	# guesswork: "Content-type"
-dc.resourceIdentifier		= 1=12	# "Local number"
-dc.source			= 1=1019	# "Record-source"
-dc.language			= 1=54	# "Code--language"
-dc.relation			= 1=?	###
-dc.coverage			= 1=?	###
-dc.rights			= 1=?	###
-#
-# Aside from the mainstream qualifiers -- the Dublin Core stuff, Bath
-# Profile stuff and suchlike -- this file may also specific a few
-# special qualifiers in the "cql-java" pseudo-qualifier-set, and these
-# affect the translation of qualifiers into Type-1 attributes as
-# follows:
-#
+qualifier.srw.serverChoice		= 1=1016
+	# "any"
+
+qualifier.dc.title			= 1=4
+qualifier.dc.subject			= 1=21
+qualifier.dc.creator			= 1=1003
+qualifier.dc.author			= 1=1003
+	### Unofficial synonym for "creator"
+qualifier.dc.editor			= 1=1020
+qualifier.dc.publisher			= 1=1018
+qualifier.dc.description		= 1=62
+	# "abstract"
+qualifier.dc.date			= 1=30
+qualifier.dc.resourceType		= 1=1031
+	# guesswork: "Material-type"
+qualifier.dc.format			= 1=1034
+	# guesswork: "Content-type"
+qualifier.dc.resourceIdentifier		= 1=12
+	# "Local number"
+qualifier.dc.source			= 1=1019
+	# "Record-source"
+qualifier.dc.language			= 1=54
+	# "Code--language"
+qualifier.dc.relation			= 1=?
+	### No idea how to represent this
+qualifier.dc.coverage			= 1=?
+	### No idea how to represent this
+qualifier.dc.rights			= 1=?
+	### No idea how to represent this
+
+### These aren't right: I've just put them here for the Generator
+qualifier.bath.subject			= 1=21
+qualifier.bath.author			= 1=1003
+qualifier.foo>bar			= 1=2000
+
 # Relation attributes are selected according to the CQL relation by
-# looking up the "cql-java.relation.<relation>" property:
-#
-cql-java.relation.<		= 2=1
-cql-java.relation.<=		= 2=2
-cql-java.relation.=		= 2=3
-cql-java.relation.exact		= 2=3
-cql-java.relation.>=		= 2=4
-cql-java.relation.>		= 2=5
-cql-java.relation.<>		= 2=6
+# looking up the "relation.<relation>" property:
 #
-#	### Should add support for relation modifiers
+relation.<				= 2=1
+relation.le				= 2=2
+relation.eq				= 2=3
+relation.exact				= 2=3
+relation.ge				= 2=4
+relation.>				= 2=5
+relation.<>				= 2=6
+
+### These two are not really right:
+relation.all				= 2=3
+relation.any				= 2=3
+
+# Relation modifiers.
 #
+relationModifier.relevant		= 2=102
+relationModifier.fuzzy			= 2=100
+	### 100 is "phonetic", which is not quite the same thing
+relationModifier.stem			= 2=101
+
 # Position attributes may be specified for anchored terms (those
 # beginning with "^", which is stripped) and unanchored (those not
 # beginning with "^").  This may change when we get a BIB-1 truncation
 # attribute that says "do what CQL does".
 #
-cql-java.position.anchored	= 3=1	# "first in field"
-cql-java.position.unanchored	= 3=3	# "any position in field"
-#
+position.anchored			= 3=1
+	# "first in field"
+position.unanchored			= 3=3
+	# "any position in field"
+
 # Structure attributes may be specified for individual relations; a
 # default structure attribute my be specified by the pseudo-relation
 # "*", to be used whenever a relation not listed here occurs.
 #
-cql-java.structure.exact	= 4=108	# phrase
-cql-java.structure.*		= 4=1	# phrase
-#
+structure.exact				= 4=108
+	# phrase
+structure.*				= 4=1
+	# phrase
+
 # Finally, any additional attributes that should always be included
-# with each term can be specified in the "cql-java.always" property.
+# with each term can be specified in the "always" property.
 #
-cql-java.always			= 5=104 6=1
+always					= 5=104 6=1
 # 5=104: some kind of vaguely CQL-like masking, IIRC.
 # 6=1: completeness = incomplete subfield
diff --git a/src/org/z3950/zing/cql/CQLBooleanNode.java b/src/org/z3950/zing/cql/CQLBooleanNode.java
index a3c3749..b0ca761 100644
--- a/src/org/z3950/zing/cql/CQLBooleanNode.java
+++ b/src/org/z3950/zing/cql/CQLBooleanNode.java
@@ -1,12 +1,13 @@
-// $Id: CQLBooleanNode.java,v 1.7 2002-11-06 00:05:58 mike Exp $
+// $Id: CQLBooleanNode.java,v 1.8 2002-11-06 20:13:45 mike Exp $
 
 package org.z3950.zing.cql;
+import java.util.Properties;
 
 
 /**
  * Represents a boolean node in a CQL parse-tree.
  *
- * @version	$Id: CQLBooleanNode.java,v 1.7 2002-11-06 00:05:58 mike Exp $
+ * @version	$Id: CQLBooleanNode.java,v 1.8 2002-11-06 20:13:45 mike Exp $
  */
 public abstract class CQLBooleanNode extends CQLNode {
     CQLBooleanNode() {}		// prevent javadoc from documenting this
@@ -21,18 +22,16 @@ public abstract class CQLBooleanNode extends CQLNode {
      */ 
     public CQLNode right;
 
-    abstract String op();
-
     public String toXCQL(int level) {
 	return (indent(level) + "<triple>\n" +
-		booleanXQL(level+1) +
+		opXQL(level+1) +
 		left.toXCQL(level+1) +
 		right.toXCQL(level+1) +
 		indent(level) + "</triple>\n");
     }
 
     // Represents the boolean operation itself: overridden for CQLProxNode
-    String booleanXQL(int level) {
+    String opXQL(int level) {
 	return(indent(level) + "<boolean>\n" +
 	       indent(level+1) + "<value>" + op() + "</value>\n" +
 	       indent(level) + "</boolean>\n");
@@ -42,4 +41,15 @@ public abstract class CQLBooleanNode extends CQLNode {
 	// ### We don't always need parens around the operands
 	return "(" + left.toCQL() + ") " + op() + " (" + right.toCQL() + ")";
     }
+
+    public String toPQF(Properties config) throws PQFTranslationException {
+	return ("@" + opPQF() +
+		" " + left.toPQF(config) +
+		" " + right.toPQF(config));
+    }
+
+    // represents the operation for PQF: overridden for CQLProxNode
+    String opPQF() { return op(); }
+
+    abstract String op();
 }
diff --git a/src/org/z3950/zing/cql/CQLNode.java b/src/org/z3950/zing/cql/CQLNode.java
index 24a2d27..eab6db4 100644
--- a/src/org/z3950/zing/cql/CQLNode.java
+++ b/src/org/z3950/zing/cql/CQLNode.java
@@ -1,4 +1,4 @@
-// $Id: CQLNode.java,v 1.11 2002-11-06 00:05:58 mike Exp $
+// $Id: CQLNode.java,v 1.12 2002-11-06 20:13:45 mike Exp $
 
 package org.z3950.zing.cql;
 import java.util.Properties;
@@ -7,7 +7,7 @@ import java.util.Properties;
 /**
  * Represents a node in a CQL parse-tree.
  *
- * @version	$Id: CQLNode.java,v 1.11 2002-11-06 00:05:58 mike Exp $
+ * @version	$Id: CQLNode.java,v 1.12 2002-11-06 20:13:45 mike Exp $
  */
 public abstract class CQLNode {
     CQLNode() {}		// prevent javadoc from documenting this
@@ -39,13 +39,32 @@ public abstract class CQLNode {
     /**
      * Renders a parse-tree into a Yaz-style PQF string.
      * <P>
+     * <PRE>
+	query ::= top-set query-struct.
+	top-set ::= [ '@attrset' string ]
+	query-struct ::= attr-spec | simple | complex | '@term' term-type
+	attr-spec ::= '@attr' [ string ] string query-struct
+	complex ::= operator query-struct query-struct.
+	operator ::= '@and' | '@or' | '@not' | '@prox' proximity.
+	simple ::= result-set | term.
+	result-set ::= '@set' string.
+	term ::= string.
+	proximity ::= exclusion distance ordered relation which-code unit-code.
+	exclusion ::= '1' | '0' | 'void'.
+	distance ::= integer.
+	ordered ::= '1' | '0'.
+	relation ::= integer.
+	which-code ::= 'known' | 'private' | integer.
+	unit-code ::= integer.
+	term-type ::= 'general' | 'numeric' | 'string' | 'oid' | 'datetime' | 'null'.
+     * </PRE>
      * @return
      *	A String containing a PQF query equivalent to the parse-tree
      *	whose root is this node.  This may be fed into the tool of
      *	your choice to obtain a BER-encoded packet.
      */
     abstract public String toPQF(Properties config)
-	throws UnknownQualifierException, UnknownRelationException;
+	throws PQFTranslationException;
 
     /**
      * Returns a String of spaces for indenting to the specified level.
diff --git a/src/org/z3950/zing/cql/CQLParseException.java b/src/org/z3950/zing/cql/CQLParseException.java
index ed0e0c6..845dfff 100644
--- a/src/org/z3950/zing/cql/CQLParseException.java
+++ b/src/org/z3950/zing/cql/CQLParseException.java
@@ -1,4 +1,4 @@
-// $Id: CQLParseException.java,v 1.1 2002-10-30 09:19:26 mike Exp $
+// $Id: CQLParseException.java,v 1.2 2002-11-06 20:13:45 mike Exp $
 
 package org.z3950.zing.cql;
 import java.lang.Exception;
@@ -7,10 +7,16 @@ import java.lang.Exception;
 /**
  * Exception indicating that an error ocurred parsing CQL.
  *
- * @version	$Id: CQLParseException.java,v 1.1 2002-10-30 09:19:26 mike Exp $
+ * @version	$Id: CQLParseException.java,v 1.2 2002-11-06 20:13:45 mike Exp $
  */
 public class CQLParseException extends Exception {
-    CQLParseException(String s) {
+    /**
+     * Creates a new <TT>CQLParseException</TT>.
+     * @param s
+     *	An error message describing the problem with the query,
+     *	usually a syntax error of some kind.
+     */
+    public CQLParseException(String s) {
 	super(s);
     }
 }
diff --git a/src/org/z3950/zing/cql/CQLParser.java b/src/org/z3950/zing/cql/CQLParser.java
index 59cedf8..a365030 100644
--- a/src/org/z3950/zing/cql/CQLParser.java
+++ b/src/org/z3950/zing/cql/CQLParser.java
@@ -1,4 +1,4 @@
-// $Id: CQLParser.java,v 1.15 2002-11-06 00:05:58 mike Exp $
+// $Id: CQLParser.java,v 1.16 2002-11-06 20:13:45 mike Exp $
 
 package org.z3950.zing.cql;
 import java.io.IOException;
@@ -12,7 +12,7 @@ import java.io.FileNotFoundException;
 /**
  * Compiles CQL strings into parse trees of CQLNode subtypes.
  *
- * @version	$Id: CQLParser.java,v 1.15 2002-11-06 00:05:58 mike Exp $
+ * @version	$Id: CQLParser.java,v 1.16 2002-11-06 20:13:45 mike Exp $
  * @see		<A href="http://zing.z3950.org/cql/index.html"
  *		        >http://zing.z3950.org/cql/index.html</A>
  */
@@ -328,7 +328,7 @@ public class CQLParser {
 	    try {
 		// Read in the whole of standard input in one go
 		int nbytes = System.in.read(bytes);
-	    } catch (java.io.IOException ex) {
+	    } catch (IOException ex) {
 		System.err.println("Can't read query: " + ex.getMessage());
 		System.exit(2);
 	    }
@@ -342,7 +342,7 @@ public class CQLParser {
 	} catch (CQLParseException ex) {
 	    System.err.println("Syntax error: " + ex.getMessage());
 	    System.exit(3);
-	} catch (java.io.IOException ex) {
+	} catch (IOException ex) {
 	    System.err.println("Can't compile query: " + ex.getMessage());
 	    System.exit(4);
 	}
@@ -362,9 +362,25 @@ public class CQLParser {
 	    } else {
 		System.out.print(root.toXCQL(0));
 	    }
-	} catch (java.io.IOException ex) {
+	} catch (IOException ex) {
 	    System.err.println("Can't render query: " + ex.getMessage());
 	    System.exit(5);
+	} catch (UnknownQualifierException ex) {
+	    System.err.println("Unknown qualifier: " + ex.getMessage());
+	    System.exit(6);
+	} catch (UnknownRelationException ex) {
+	    System.err.println("Unknown relation: " + ex.getMessage());
+	    System.exit(7);
+	} catch (UnknownRelationModifierException ex) {
+	    System.err.println("Unknown relation modifier: " +
+			       ex.getMessage());
+	    System.exit(8);
+	} catch (UnknownPositionException ex) {
+	    System.err.println("Unknown position: " + ex.getMessage());
+	    System.exit(9);
+	} catch (PQFTranslationException ex) {
+	    // We catch all of this class's subclasses, so --
+	    throw new Error("can't get a PQFTranslationException");
 	}
     }
 }
diff --git a/src/org/z3950/zing/cql/CQLProxNode.java b/src/org/z3950/zing/cql/CQLProxNode.java
index 8c69ecc..b3a8dca 100644
--- a/src/org/z3950/zing/cql/CQLProxNode.java
+++ b/src/org/z3950/zing/cql/CQLProxNode.java
@@ -1,6 +1,7 @@
-// $Id: CQLProxNode.java,v 1.2 2002-11-06 00:05:58 mike Exp $
+// $Id: CQLProxNode.java,v 1.3 2002-11-06 20:13:45 mike Exp $
 
 package org.z3950.zing.cql;
+import java.util.Vector;
 
 
 /**
@@ -9,7 +10,7 @@ package org.z3950.zing.cql;
  * candidate records which are sufficiently close to each other, as
  * specified by a set of proximity parameters.
  *
- * @version	$Id: CQLProxNode.java,v 1.2 2002-11-06 00:05:58 mike Exp $
+ * @version	$Id: CQLProxNode.java,v 1.3 2002-11-06 20:13:45 mike Exp $
  */
 public class CQLProxNode extends CQLBooleanNode {
     ModifierSet ms;
@@ -38,10 +39,6 @@ public class CQLProxNode extends CQLBooleanNode {
 	this.right = right;
     }
 
-    String op() {
-	return ms.toCQL();
-    }
-
     /**
      * Adds a modifier of the specified <TT>type</TT> and
      * <TT>value</TT> to a proximity node.  Valid types are
@@ -57,9 +54,73 @@ public class CQLProxNode extends CQLBooleanNode {
 	ms.addModifier(type, value);
     }
 
-    // ### should have a public method to retrieve all modifiers
+    /**
+     * Returns an array of the modifiers associated with a proximity
+     * node.
+     * @return
+     *	An array of modifiers, each represented by a two-element
+     *	<TT>Vector</TT>, in which element 0 is the modifier type
+     *	(e.g. <TT>distance</TT> or <TT>ordering</TT>) and element 1 is
+     *	the associated value (e.g. <TT>3</TT> or <TT>unordered</TT>).
+     */
+    public Vector[] getModifiers() {
+	return ms.getModifiers();
+    }
+
+    String op() {
+	return ms.toCQL();
+    }
 
-    String booleanXQL(int level) {
+    String opXQL(int level) {
 	return ms.toXCQL(level, "boolean");
     }
+
+    /*
+     * proximity ::= exclusion distance ordered relation which-code unit-code.
+     * exclusion ::= '1' | '0' | 'void'.
+     * distance ::= integer.
+     * ordered ::= '1' | '0'.
+     * relation ::= integer.
+     * which-code ::= 'known' | 'private' | integer.
+     * unit-code ::= integer.
+     */
+    String opPQF() {
+	String rel = ms.modifier("relation");
+	int relCode = 0;
+	if (rel.equals("<")) {
+	    relCode = 1;
+	} else if (rel.equals("<=")) {
+	    relCode = 2;
+	} else if (rel.equals("=")) {
+	    relCode = 3;
+	} else if (rel.equals(">=")) {
+	    relCode = 4;
+	} else if (rel.equals(">")) {
+	    relCode = 5;
+	} else if (rel.equals("<>")) {
+	    relCode = 6;
+	}
+
+	String unit = ms.modifier("unit");
+	int unitCode = 0;
+	if (unit.equals("word")) {
+	    unitCode = 2;
+	} else if (unit.equals("sentence")) {
+	    unitCode = 3;
+	} else if (unit.equals("paragraph")) {
+	    unitCode = 4;
+	} else if (unit.equals("element")) {
+	    unitCode = 8;
+	}
+
+	String res = "prox " +
+	    "0 " +
+	    ms.modifier("distance") + " " +
+	    (ms.modifier("ordering").equals("ordered") ? 1 : 0) + " " +
+	    relCode + " " +
+	    "1 " +
+	    unitCode;
+	
+	return res;
+    }
 }
diff --git a/src/org/z3950/zing/cql/CQLRelation.java b/src/org/z3950/zing/cql/CQLRelation.java
index f82b91e..0d98674 100644
--- a/src/org/z3950/zing/cql/CQLRelation.java
+++ b/src/org/z3950/zing/cql/CQLRelation.java
@@ -1,4 +1,4 @@
-// $Id: CQLRelation.java,v 1.4 2002-11-06 00:14:32 mike Exp $
+// $Id: CQLRelation.java,v 1.5 2002-11-06 20:13:45 mike Exp $
 
 package org.z3950.zing.cql;
 import java.util.Vector;
@@ -7,9 +7,8 @@ import java.lang.StringBuffer;
 
 /**
  * Represents a relation between a CQL qualifier and term.
- * ##
  *
- * @version	$Id: CQLRelation.java,v 1.4 2002-11-06 00:14:32 mike Exp $
+ * @version	$Id: CQLRelation.java,v 1.5 2002-11-06 20:13:45 mike Exp $
  */
 public class CQLRelation extends CQLNode {
     ModifierSet ms;
@@ -26,7 +25,15 @@ public class CQLRelation extends CQLNode {
 	ms.addModifier(null, modifier);
     }
 
-    // ### should have a public method to retrieve all modifiers
+    public String[] getModifiers() {
+	Vector[] v = ms.getModifiers();
+	int n = v.length;
+	String[] s = new String[n];
+	for (int i = 0; i < n; i++) {
+	    s[i] = (String) v[i].get(1);
+	}
+	return s;
+    }
 
     public String toXCQL(int level) {
 	return ms.toXCQL(level, "relation");
@@ -36,8 +43,7 @@ public class CQLRelation extends CQLNode {
 	return ms.toCQL();
     }
 
-    public String toPQF(Properties config)
-	throws UnknownQualifierException, UnknownRelationException {
-	throw Error("CQLRelation.toPQF() can never be called");
+    public String toPQF(Properties config) throws PQFTranslationException {
+	throw new Error("CQLRelation.toPQF() can never be called");
     }
 }
diff --git a/src/org/z3950/zing/cql/CQLTermNode.java b/src/org/z3950/zing/cql/CQLTermNode.java
index 5889354..9e7a7b9 100644
--- a/src/org/z3950/zing/cql/CQLTermNode.java
+++ b/src/org/z3950/zing/cql/CQLTermNode.java
@@ -1,4 +1,4 @@
-// $Id: CQLTermNode.java,v 1.7 2002-11-06 00:05:58 mike Exp $
+// $Id: CQLTermNode.java,v 1.8 2002-11-06 20:13:45 mike Exp $
 
 package org.z3950.zing.cql;
 import java.util.Properties;
@@ -12,7 +12,7 @@ import java.util.Vector;
  * these must be provided - you can't have a qualifier without a
  * relation or vice versa.
  *
- * @version	$Id: CQLTermNode.java,v 1.7 2002-11-06 00:05:58 mike Exp $
+ * @version	$Id: CQLTermNode.java,v 1.8 2002-11-06 20:13:45 mike Exp $
  */
 public class CQLTermNode extends CQLNode {
     private String qualifier;
@@ -55,41 +55,66 @@ public class CQLTermNode extends CQLNode {
 	return res;
     }
 
-    public String toPQF(Properties config)
-	throws UnknownQualifierException, UnknownRelationException {
+    public String toPQF(Properties config) throws PQFTranslationException {
 	Vector attrs = new Vector();
 
-	if (qualifier != null) {
-	    String s = config.getProperty(qualifier);
-	    if (s == null)
-		throw new UnknownQualifierException(qualifier);
-	    attrs.add(s);
-	} else {
-	    // ### get a default access point from properties?
+	String attr;
+	attr = config.getProperty("qualifier." + qualifier);
+	if (attr == null)
+	    throw new UnknownQualifierException(qualifier);
+	attrs.add(attr);
+
+	String rel = relation.getBase();
+	if (rel.equals("=")) {
+	    rel = "eq";
+	} else if (rel.equals("<=")) {
+	    rel = "le";
+	} else if (rel.equals(">=")) {
+	    rel = "ge";
+	}
+	// ### Handling "any" and "all" properly would involve breaking
+	// the string down into a bunch of individual words and ORring
+	// or ANDing them together.  Another day.
+	attr = config.getProperty("relation." + rel);
+	if (attr == null)
+	    throw new UnknownRelationException(rel);
+	attrs.add(attr);
+
+	String[] mods = relation.getModifiers();
+	for (int i = 0; i < mods.length; i++) {
+	    attr = config.getProperty("relationModifier." + mods[i]);
+	    if (attr == null)
+		throw new UnknownRelationModifierException(mods[i]);
+	    attrs.add(attr);
 	}
 
-	if (relation != null) {
-	    String rel = relation.getBase();
-	    // ### handle "any" and "all"
-	    String s = config.getProperty("cql-java.relation." + rel);
-	    if (s == null)
-		throw new UnknownRelationException(rel);
-	    attrs.add(s);
-	} else {
-	    // ### get a default relation from properties?
+	String pos = "unanchored";
+	String text = term;
+	if (text.length() > 0 && text.substring(0, 1).equals("^")) {
+	    text = text.substring(1);
+	    pos = "anchored";
 	}
+	attr = config.getProperty("position." + pos);
+	if (attr == null)
+	    throw new UnknownPositionException(pos);
+	attrs.add(attr);
+
+	attr = config.getProperty("structure." + rel);
+	if (attr == null)
+	    attr = config.getProperty("structure.*");
+	attrs.add(attr);
 
-	// ### handle position attributes
-	// ### handle structure attributes
-	// ### handle "always" attributes
+	attr = config.getProperty("always");
+	if (attr != null)
+	    attrs.add(attr);
 
-	// ### should split Vector elements on spaces
 	String s = "";
 	for (int i = 0; i < attrs.size(); i++) {
-	    s += "@attr " + (String) attrs.get(i) + " ";
+	    attr = (String) attrs.get(i);
+	    s += "@attr " + Utils.replaceString(attr, " ", " @attr ") + " ";
 	}
 
-	return s + maybeQuote(term);
+	return s + maybeQuote(text);
     }
 
     static String maybeQuote(String str) {
diff --git a/src/org/z3950/zing/cql/Makefile b/src/org/z3950/zing/cql/Makefile
index fd3a211..961afbb 100644
--- a/src/org/z3950/zing/cql/Makefile
+++ b/src/org/z3950/zing/cql/Makefile
@@ -1,4 +1,4 @@
-# $Id: Makefile,v 1.7 2002-11-06 00:05:58 mike Exp $
+# $Id: Makefile,v 1.8 2002-11-06 20:13:45 mike Exp $
 
 DOCDIR = ../../../../../docs
 
@@ -8,7 +8,9 @@ OBJ = Utils.class \
 	CQLRelation.class CQLProxNode.class ModifierSet.class \
 	CQLParser.class CQLLexer.class CQLParseException.class \
 	CQLGenerator.class MissingParameterException.class \
-	UnknownQualifierException.class UnknownRelationException.class
+	PQFTranslationException.class \
+	UnknownQualifierException.class UnknownRelationException.class \
+	UnknownRelationModifierException.class UnknownPositionException.class
 
 ../../../../../lib/cql-java.jar: $(OBJ)
 	cd ../../../..; jar cf ../lib/cql-java.jar org/z3950/zing/cql/*.class
diff --git a/src/org/z3950/zing/cql/MissingParameterException.java b/src/org/z3950/zing/cql/MissingParameterException.java
index 3d184bd..3b54668 100644
--- a/src/org/z3950/zing/cql/MissingParameterException.java
+++ b/src/org/z3950/zing/cql/MissingParameterException.java
@@ -1,4 +1,4 @@
-// $Id: MissingParameterException.java,v 1.1 2002-11-06 00:05:58 mike Exp $
+// $Id: MissingParameterException.java,v 1.2 2002-11-06 20:13:45 mike Exp $
 
 package org.z3950.zing.cql;
 import java.lang.Exception;
@@ -7,10 +7,15 @@ import java.lang.Exception;
 /**
  * Exception indicating that a required property was not specified.
  *
- * @version	$Id: MissingParameterException.java,v 1.1 2002-11-06 00:05:58 mike Exp $
+ * @version	$Id: MissingParameterException.java,v 1.2 2002-11-06 20:13:45 mike Exp $
  */
 public class MissingParameterException extends Exception {
-    MissingParameterException(String s) {
+    /**
+     * Creates a new <TT>MissingParameterException</TT>.
+     * @param s
+     *	The name of the property whose value was required but not supplied.
+     */
+    public MissingParameterException(String s) {
 	super(s);
     }
 }
diff --git a/src/org/z3950/zing/cql/ModifierSet.java b/src/org/z3950/zing/cql/ModifierSet.java
index 4f61bed..8b8c245 100644
--- a/src/org/z3950/zing/cql/ModifierSet.java
+++ b/src/org/z3950/zing/cql/ModifierSet.java
@@ -1,4 +1,4 @@
-// $Id: ModifierSet.java,v 1.3 2002-11-06 00:05:58 mike Exp $
+// $Id: ModifierSet.java,v 1.4 2002-11-06 20:13:45 mike Exp $
 
 package org.z3950.zing.cql;
 import java.util.Vector;
@@ -11,7 +11,7 @@ import java.lang.StringBuffer;
  * CQLProxNode - two functionally very separate classes that happen to
  * require the same data structures and functionality.
  *
- * @version $Id: ModifierSet.java,v 1.3 2002-11-06 00:05:58 mike Exp $
+ * @version $Id: ModifierSet.java,v 1.4 2002-11-06 20:13:45 mike Exp $
  */
 public class ModifierSet {
     String base;
@@ -33,6 +33,16 @@ public class ModifierSet {
 	modifiers.add(modifier);
     }
 
+    public String modifier(String type) {
+	int n = modifiers.size();
+	for (int i = 0; i < n; i++) {
+	    Vector pair = (Vector) modifiers.get(i);
+	    if (pair.get(0).equals(type))
+		return (String) pair.get(1);
+	}
+	return null;
+    }
+
     public Vector[] getModifiers() {
 	int n = modifiers.size();
 	Vector[] res = new Vector[n];
diff --git a/src/org/z3950/zing/cql/PQFTranslationException.java b/src/org/z3950/zing/cql/PQFTranslationException.java
new file mode 100644
index 0000000..85ec184
--- /dev/null
+++ b/src/org/z3950/zing/cql/PQFTranslationException.java
@@ -0,0 +1,16 @@
+// $Id: PQFTranslationException.java,v 1.1 2002-11-06 20:13:45 mike Exp $
+
+package org.z3950.zing.cql;
+import java.lang.Exception;
+
+
+/**
+ * Base class for exceptions occurring when translating parse trees to PQF.
+ *
+ * @version $Id: PQFTranslationException.java,v 1.1 2002-11-06 20:13:45 mike Exp $
+ */
+public class PQFTranslationException extends Exception {
+    PQFTranslationException(String s) {
+	super(s);
+    }
+}
diff --git a/src/org/z3950/zing/cql/UnknownPositionException.java b/src/org/z3950/zing/cql/UnknownPositionException.java
new file mode 100644
index 0000000..39f4927
--- /dev/null
+++ b/src/org/z3950/zing/cql/UnknownPositionException.java
@@ -0,0 +1,27 @@
+// $Id: UnknownPositionException.java,v 1.1 2002-11-06 20:13:45 mike Exp $
+
+package org.z3950.zing.cql;
+import java.lang.Exception;
+
+
+/**
+ * Exception indicating that a position was not recognised.
+ * When rendering a tree out as PQF, each term is classified either as
+ * <TT>anchored</TT> or <TT>unanchored</TT>, depending on whether it
+ * begins with the word-anchoring meta-character <TT>^</TT>, and its
+ * classification is looked up as a <TT>position</TT> in the PQF
+ * configuration.  If the position is not configured, we throw one of
+ * these babies.
+ *
+ * @version $Id: UnknownPositionException.java,v 1.1 2002-11-06 20:13:45 mike Exp $
+ */
+public class UnknownPositionException extends PQFTranslationException {
+    /**
+     * Creates a new <TT>UnknownPositionException</TT>.
+     * @param s
+     *	The position for which there was no PQF configuration.
+     */
+    public UnknownPositionException(String s) {
+	super(s);
+    }
+}
diff --git a/src/org/z3950/zing/cql/UnknownQualifierException.java b/src/org/z3950/zing/cql/UnknownQualifierException.java
index ba43baf..8bad79e 100644
--- a/src/org/z3950/zing/cql/UnknownQualifierException.java
+++ b/src/org/z3950/zing/cql/UnknownQualifierException.java
@@ -1,4 +1,4 @@
-// $Id: UnknownQualifierException.java,v 1.1 2002-11-06 00:05:58 mike Exp $
+// $Id: UnknownQualifierException.java,v 1.2 2002-11-06 20:13:45 mike Exp $
 
 package org.z3950.zing.cql;
 import java.lang.Exception;
@@ -9,12 +9,18 @@ import java.lang.Exception;
  * At compilation time, we accept any syntactically valid qualifier;
  * but when rendering a tree out as PQF, we need to translate the
  * qualifiers into sets of Type-1 query attributes.  If we can't do
- * that, we throw one of these babies.
+ * that, because the PQF configuration doesn't know about a relation,
+ * we throw one of these babies.
  *
- * @version $Id: UnknownQualifierException.java,v 1.1 2002-11-06 00:05:58 mike Exp $
+ * @version $Id: UnknownQualifierException.java,v 1.2 2002-11-06 20:13:45 mike Exp $
  */
-public class UnknownQualifierException extends Exception {
-    UnknownQualifierException(String s) {
+public class UnknownQualifierException extends PQFTranslationException {
+    /**
+     * Creates a new <TT>UnknownQualifierException</TT>.
+     * @param s
+     *	The qualifier for which there was no PQF configuration.
+     */
+    public UnknownQualifierException(String s) {
 	super(s);
     }
 }
diff --git a/src/org/z3950/zing/cql/UnknownRelationException.java b/src/org/z3950/zing/cql/UnknownRelationException.java
index 6029bf4..4d65e72 100644
--- a/src/org/z3950/zing/cql/UnknownRelationException.java
+++ b/src/org/z3950/zing/cql/UnknownRelationException.java
@@ -1,4 +1,4 @@
-// $Id: UnknownRelationException.java,v 1.1 2002-11-06 00:05:58 mike Exp $
+// $Id: UnknownRelationException.java,v 1.2 2002-11-06 20:13:45 mike Exp $
 
 package org.z3950.zing.cql;
 import java.lang.Exception;
@@ -9,12 +9,18 @@ import java.lang.Exception;
  * At compilation time, we accept any syntactically valid relation;
  * but when rendering a tree out as PQF, we need to translate the
  * relations into sets of Type-1 query attributes.  If we can't do
- * that, we throw one of these babies.
+ * that, because the PQF configuration doesn't know about a relation,
+ * we throw one of these babies.
  *
- * @version $Id: UnknownRelationException.java,v 1.1 2002-11-06 00:05:58 mike Exp $
+ * @version $Id: UnknownRelationException.java,v 1.2 2002-11-06 20:13:45 mike Exp $
  */
-public class UnknownRelationException extends Exception {
-    UnknownRelationException(String s) {
+public class UnknownRelationException extends PQFTranslationException {
+    /**
+     * Creates a new <TT>UnknownRelationException</TT>.
+     * @param s
+     *	The relation for which there was no PQF configuration.
+     */
+    public UnknownRelationException(String s) {
 	super(s);
     }
 }
diff --git a/src/org/z3950/zing/cql/UnknownRelationModifierException.java b/src/org/z3950/zing/cql/UnknownRelationModifierException.java
new file mode 100644
index 0000000..9d449b5
--- /dev/null
+++ b/src/org/z3950/zing/cql/UnknownRelationModifierException.java
@@ -0,0 +1,26 @@
+// $Id: UnknownRelationModifierException.java,v 1.1 2002-11-06 20:13:45 mike Exp $
+
+package org.z3950.zing.cql;
+import java.lang.Exception;
+
+
+/**
+ * Exception indicating that a relation modifier was not recognised.
+ * At compilation time, we accept any syntactically valid relation modifier;
+ * but when rendering a tree out as PQF, we need to translate the
+ * relation modifiers into sets of Type-1 query attributes.  If we can't do
+ * that, because the PQF configuration doesn't know about a relation modifier,
+ * we throw one of these babies.
+ *
+ * @version $Id: UnknownRelationModifierException.java,v 1.1 2002-11-06 20:13:45 mike Exp $
+ */
+public class UnknownRelationModifierException extends PQFTranslationException {
+    /**
+     * Creates a new <TT>UnknownRelationModifierException</TT>.
+     * @param s
+     *	The relation modifier for which there was no PQF configuration.
+     */
+    public UnknownRelationModifierException(String s) {
+	super(s);
+    }
+}