001: package com.quadcap.sql;
002:
003: /* Copyright 1999 - 2003 Quadcap Software. All rights reserved.
004: *
005: * This software is distributed under the Quadcap Free Software License.
006: * This software may be used or modified for any purpose, personal or
007: * commercial. Open Source redistributions are permitted. Commercial
008: * redistribution of larger works derived from, or works which bundle
009: * this software requires a "Commercial Redistribution License"; see
010: * http://www.quadcap.com/purchase.
011: *
012: * Redistributions qualify as "Open Source" under one of the following terms:
013: *
014: * Redistributions are made at no charge beyond the reasonable cost of
015: * materials and delivery.
016: *
017: * Redistributions are accompanied by a copy of the Source Code or by an
018: * irrevocable offer to provide a copy of the Source Code for up to three
019: * years at the cost of materials and delivery. Such redistributions
020: * must allow further use, modification, and redistribution of the Source
021: * Code under substantially the same terms as this license.
022: *
023: * Redistributions of source code must retain the copyright notices as they
024: * appear in each source code file, these license terms, and the
025: * disclaimer/limitation of liability set forth as paragraph 6 below.
026: *
027: * Redistributions in binary form must reproduce this Copyright Notice,
028: * these license terms, and the disclaimer/limitation of liability set
029: * forth as paragraph 6 below, in the documentation and/or other materials
030: * provided with the distribution.
031: *
032: * The Software is provided on an "AS IS" basis. No warranty is
033: * provided that the Software is free of defects, or fit for a
034: * particular purpose.
035: *
036: * Limitation of Liability. Quadcap Software shall not be liable
037: * for any damages suffered by the Licensee or any third party resulting
038: * from use of the Software.
039: */
040:
041: import java.io.Externalizable;
042: import java.io.IOException;
043: import java.io.ObjectInput;
044: import java.io.ObjectOutput;
045:
046: import java.util.Enumeration;
047: import java.util.Vector;
048:
049: import java.sql.SQLException;
050:
051: import com.quadcap.sql.types.Op;
052: import com.quadcap.sql.types.Type;
053: import com.quadcap.sql.types.Value;
054:
055: import com.quadcap.util.Debug;
056:
057: /**
058: * Expression class for all binary ops.
059: *
060: * @author Stan Bailes
061: */
062: public class BinaryExpression extends Expression implements
063: Externalizable {
064: Expression e = null;
065: Expression f = null;
066: int op = -1;
067: boolean not = false;
068:
069: /**
070: * Default constructor
071: */
072: public BinaryExpression() {
073: }
074:
075: /**
076: * Parser's constructor: A binary expression node consists of an opcode and two
077: * "child" expressions.
078: */
079: public BinaryExpression(int op, Expression e, Expression f) {
080: this .op = op;
081: this .e = e;
082: this .f = f;
083: }
084:
085: public int rank() {
086: return 0;
087: }
088:
089: public Type getType(Session session, Cursor cursor)
090: throws SQLException {
091: return e.getType(session, cursor); // XXX not quite...
092: }
093:
094: public Value getValue(Session session, Cursor cursor)
095: throws SQLException {
096: Value eval = e.getValue(session, cursor);
097: Value fval = f.getValue(session, cursor);
098: Value ret = Value.binop(op, eval, fval);
099: if (not) {
100: ret = ret.unop(Op.NOT);
101: }
102: return ret;
103: }
104:
105: public void invert() {
106: not = !not;
107: }
108:
109: public String toString() {
110: String n = not ? "not " : "";
111: return n + e + " " + Op.toString(op) + " " + f;
112: }
113:
114: public void visitSubExpressions(ExpressionVisitor ev) {
115: ev.visit(e);
116: ev.visit(f);
117: }
118:
119: public void readExternal(ObjectInput in) throws IOException,
120: ClassNotFoundException {
121: e = (Expression) in.readObject();
122: f = (Expression) in.readObject();
123: op = in.readInt();
124: not = (in.read() == 1);
125: }
126:
127: public void writeExternal(ObjectOutput out) throws IOException {
128: out.writeObject(e);
129: out.writeObject(f);
130: out.writeInt(op);
131: out.write(not ? 1 : 0);
132: }
133: }
|