01: /*
02: * Copyright 1994-2003 Sun Microsystems, Inc. All Rights Reserved.
03: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
04: *
05: * This code is free software; you can redistribute it and/or modify it
06: * under the terms of the GNU General Public License version 2 only, as
07: * published by the Free Software Foundation. Sun designates this
08: * particular file as subject to the "Classpath" exception as provided
09: * by Sun in the LICENSE file that accompanied this code.
10: *
11: * This code is distributed in the hope that it will be useful, but WITHOUT
12: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14: * version 2 for more details (a copy is included in the LICENSE file that
15: * accompanied this code).
16: *
17: * You should have received a copy of the GNU General Public License version
18: * 2 along with this work; if not, write to the Free Software Foundation,
19: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20: *
21: * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22: * CA 95054 USA or visit www.sun.com if you need additional information or
23: * have any questions.
24: */
25:
26: package sun.tools.tree;
27:
28: import sun.tools.java.*;
29: import java.util.Hashtable;
30:
31: /**
32: * WARNING: The contents of this source file are not part of any
33: * supported API. Code that depends on them does so at its own risk:
34: * they are subject to change or removal without notice.
35: */
36: abstract public class BinaryLogicalExpression extends BinaryExpression {
37: /**
38: * constructor
39: */
40: public BinaryLogicalExpression(int op, long where, Expression left,
41: Expression right) {
42: super (op, where, Type.tBoolean, left, right);
43: }
44:
45: /**
46: * Check a binary expression
47: */
48: public Vset checkValue(Environment env, Context ctx, Vset vset,
49: Hashtable exp) {
50: ConditionVars cvars = new ConditionVars();
51: // evaluate the logical expression, determining which variables are
52: // set if the resulting value is true or false
53: checkCondition(env, ctx, vset, exp, cvars);
54: // return the intersection.
55: return cvars.vsTrue.join(cvars.vsFalse);
56: }
57:
58: /*
59: * Every subclass of this class must define a genuine implementation
60: * of this method. It cannot inherit the method of Expression.
61: */
62: abstract public void checkCondition(Environment env, Context ctx,
63: Vset vset, Hashtable exp, ConditionVars cvars);
64:
65: /**
66: * Inline
67: */
68: public Expression inline(Environment env, Context ctx) {
69: left = left.inlineValue(env, ctx);
70: right = right.inlineValue(env, ctx);
71: return this;
72: }
73: }
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