1 // $Id: CQLProxNode.java,v 1.8 2007-06-27 17:02:01 mike Exp $
3 package org.z3950.zing.cql;
4 import java.util.Vector;
8 * Represents a proximity node in a CQL parse-tree.
9 * The left- and right-hand-sides must be satisfied by parts of the
10 * candidate records which are sufficiently close to each other, as
11 * specified by a set of proximity parameters.
13 * @version $Id: CQLProxNode.java,v 1.8 2007-06-27 17:02:01 mike Exp $
15 public class CQLProxNode extends CQLBooleanNode {
19 * Creates a new, <I>incomplete</I>, proximity node with the
20 * specified left-hand side. No right-hand side is specified at
21 * this stage: that must be specified later, using the
22 * <TT>addSecondSubterm()</TT> method. (That may seem odd, but
23 * it's just easier to write the parser that way.)
25 * Proximity paramaters may be added at any time, before or after
26 * the right-hand-side sub-tree is added.
28 public CQLProxNode(CQLNode left) {
29 ms = new ModifierSet("prox");
31 // this.right left unresolved for now ...
35 * Sets the right-hand side of the proximity node whose
36 * left-hand-side was specified at creation time.
38 public void addSecondSubterm(CQLNode right) {
43 * Adds a modifier of the specified <TT>type</TT> and
44 * <TT>value</TT> to a proximity node. Valid types are
45 * <TT>relation</TT>, <TT>distance</TT>, <TT>unit</TT> and
48 * For information on the semantics of these paramaters, see
49 * <A href="http://zing.z3950.org/cql/intro.html#3.1"
50 * >section 3.1 (Proximity)</A> of
51 * <I>A Gentle Introduction to CQL</I></A>.
53 public void addModifier(String type, String value) {
54 ms.addModifier(type, value);
58 * Returns an array of the modifiers associated with a proximity
61 * An array of Modifier objects.
63 public Vector<Modifier> getModifiers() {
64 return ms.getModifiers();
71 String opXCQL(int level) {
72 return ms.toXCQL(level, "boolean");
76 * proximity ::= exclusion distance ordered relation which-code unit-code.
77 * exclusion ::= '1' | '0' | 'void'.
78 * distance ::= integer.
79 * ordered ::= '1' | '0'.
80 * relation ::= integer.
81 * which-code ::= 'known' | 'private' | integer.
82 * unit-code ::= integer.
85 int relCode = getRelCode();
86 int unitCode = getProxUnitCode();
88 String res = "prox " +
90 ms.modifier("distance") + " " +
91 (ms.modifier("ordering").equals("ordered") ? 1 : 0) + " " +
99 private int getRelCode() {
100 String rel = ms.modifier("relation");
101 if (rel.equals("<")) {
103 } else if (rel.equals("<=")) {
105 } else if (rel.equals("=")) {
107 } else if (rel.equals(">=")) {
109 } else if (rel.equals(">")) {
111 } else if (rel.equals("<>")) {
117 private int getProxUnitCode() {
118 String unit = ms.modifier("unit");
119 if (unit.equals("word")) {
121 } else if (unit.equals("sentence")) {
123 } else if (unit.equals("paragraph")) {
125 } else if (unit.equals("element")) {
133 byte[] op = new byte[100];
135 offset = putTag(CONTEXT, 46, CONSTRUCTED, op, 0); // Operator
136 op[offset++] = (byte)(0x80&0xff); // indefinite length
138 offset = putTag(CONTEXT, 3, CONSTRUCTED, op, offset); // prox
139 op[offset++] = (byte)(0x80&0xff); // indefinite length
141 offset = putTag(CONTEXT, 1, PRIMITIVE, op, offset); // exclusion
143 offset = putLen(numLen(value), op, offset);
144 offset = putNum(value, op, offset);
146 offset = putTag(CONTEXT, 2, PRIMITIVE, op, offset); // distance
147 value = Integer.parseInt(ms.modifier("distance"));
148 offset = putLen(numLen(value), op, offset);
149 offset = putNum(value, op, offset);
151 offset = putTag(CONTEXT, 3, PRIMITIVE, op, offset); // ordered
152 value = ms.modifier("ordering").equals("ordered") ? 1 : 0;
153 offset = putLen(numLen(value), op, offset);
154 offset = putNum(value, op, offset);
156 offset = putTag(CONTEXT, 4, PRIMITIVE, op, offset); // relationType
157 value = getRelCode();
158 offset = putLen(numLen(value), op, offset);
159 offset = putNum(value, op, offset);
161 offset = putTag(CONTEXT, 5, CONSTRUCTED, op, offset); // proximityUnitCode
162 op[offset++] = (byte)(0x80&0xff); // indefinite length
163 offset = putTag(CONTEXT, 1, PRIMITIVE, op, offset); // known
164 value = getProxUnitCode();
165 offset = putLen(numLen(value), op, offset);
166 offset = putNum(value, op, offset);
167 op[offset++] = 0x00; // end of proximityUnitCode
170 op[offset++] = 0x00; // end of prox
172 op[offset++] = 0x00; // end of Operator
175 byte[] o = new byte[offset];
176 System.arraycopy(op, 0, o, 0, offset);