01: /* Copyright (C) 2004 - 2007 db4objects Inc. http://www.db4o.com
02:
03: This file is part of the db4o open source object database.
04:
05: db4o is free software; you can redistribute it and/or modify it under
06: the terms of version 2 of the GNU General Public License as published
07: by the Free Software Foundation and as clarified by db4objects' GPL
08: interpretation policy, available at
09: http://www.db4o.com/about/company/legalpolicies/gplinterpretation/
10: Alternatively you can write to db4objects, Inc., 1900 S Norfolk Street,
11: Suite 350, San Mateo, CA 94403, USA.
12:
13: db4o is distributed in the hope that it will be useful, but WITHOUT ANY
14: WARRANTY; without even the implied warranty of MERCHANTABILITY or
15: FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16: for more details.
17:
18: You should have received a copy of the GNU General Public License along
19: with this program; if not, write to the Free Software Foundation, Inc.,
20: 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
21: package EDU.purdue.cs.bloat.tree;
22:
23: import EDU.purdue.cs.bloat.editor.*;
24:
25: /**
26: * StackExpr represents an expression that is stored on the stack.
27: */
28: public class StackExpr extends VarExpr {
29: /**
30: * Constructor.
31: *
32: * @param index
33: * Location (offset) in stack of the information to which the
34: * expression refers. Index 0 represents the bottom of the stack.
35: * @param type
36: * The type of this expression.
37: */
38: public StackExpr(final int index, final Type type) {
39: super (index, type);
40: }
41:
42: public void visitForceChildren(final TreeVisitor visitor) {
43: }
44:
45: public void visit(final TreeVisitor visitor) {
46: visitor.visitStackExpr(this );
47: }
48:
49: public int exprHashCode() {
50: return 20 + index + type.simple().hashCode();
51: }
52:
53: public boolean equalsExpr(final Expr other) {
54: return (other instanceof StackExpr)
55: && ((StackExpr) other).type.simple().equals(
56: type.simple())
57: && (((StackExpr) other).index == index);
58: }
59:
60: public Object clone() {
61: return copyInto(new StackExpr(index, type));
62: }
63: }
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