update documentation

[cql-java-moved-to-github.git] / src / org / z3950 / zing / cql / CQLNode.java

diff --git a/src/org/z3950/zing/cql/CQLNode.java b/src/org/z3950/zing/cql/CQLNode.java
index eab6db4..5965da6 100644 (file)
--- a/src/org/z3950/zing/cql/CQLNode.java
+++ b/src/org/z3950/zing/cql/CQLNode.java
@@ -1,13 +1,14 @@
-// $Id: CQLNode.java,v 1.12 2002-11-06 20:13:45 mike Exp $
+// $Id: CQLNode.java,v 1.15 2002-11-20 01:15:15 mike Exp $
 
 package org.z3950.zing.cql;
 import java.util.Properties;
+import java.util.Vector;
 
 
 /**
  * Represents a node in a CQL parse-tree.
  *
- * @version    $Id: CQLNode.java,v 1.12 2002-11-06 20:13:45 mike Exp $
+ * @version    $Id: CQLNode.java,v 1.15 2002-11-20 01:15:15 mike Exp $
  */
 public abstract class CQLNode {
     CQLNode() {}               // prevent javadoc from documenting this
@@ -24,7 +25,27 @@ public abstract class CQLNode {
      * A String containing an XCQL document equivalent to the
      * parse-tree whose root is this node.
      */
-    abstract public String toXCQL(int level);
+    public String toXCQL(int level) {
+       return toXCQL(level, new Vector());
+    }
+
+    abstract public String toXCQL(int level, Vector prefixes);
+
+    protected static String renderPrefixes(int level, Vector prefixes) {
+       if (prefixes.size() == 0)
+           return "";
+       String res = indent(level) + "<prefixes>\n";
+       for (int i = 0; i < prefixes.size(); i++) {
+           CQLPrefix p = (CQLPrefix) prefixes.get(i);
+           res += indent(level+1) + "<prefix>\n";
+           if (p.name != null)
+               res += indent(level+2) + "<name>" + p.name + "</name>\n";
+           res += indent(level+2) +
+               "<identifier>" + p.identifier + "</identifier>\n";
+           res += indent(level+1) + "</prefix>\n";
+       }
+       return res + indent(level) + "</prefixes>\n";
+    }
 
     /**
      * Decompiles a parse-tree into a CQL query.
@@ -38,26 +59,21 @@ public abstract class CQLNode {
 
     /**
      * Renders a parse-tree into a Yaz-style PQF string.
+     * PQF, or Prefix Query Format, is a cryptic but powerful notation
+     * that can be trivially mapped, one-to-one, int Z39.50 Type-1 and
+     * Type-101 queries.  A specification for the format can be found
+     * in
+     * <A href="http://indexdata.dk/yaz/doc/tools.php#PQF"
+     * >Chapter 7 (Supporting Tools)</A> of the
+     * <A href="http://indexdata.dk/yaz/">YAZ</A> manual.
      * <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>
+     * @param config
+     * A <TT>Properties</TT> object containing configuration
+     * information that specifies the mapping from CQL qualifiers,
+     * relations, etc. to Type-1 attributes.  The mapping
+     * specification is described in the cql-java distribution's
+     * sample PQF-mapping configuration file,
+     * <TT>etc/pqf.properties</TT>, which see.
      * @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