diff graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/AlwaysValidAssumption.java @ 13322:f28ea693056f

New assumption utilities.
author Chris Seaton <chris.seaton@oracle.com>
date Fri, 13 Dec 2013 15:53:30 +0000
parents
children 1c446564d36c
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/AlwaysValidAssumption.java	Fri Dec 13 15:53:30 2013 +0000
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+/*
+ * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.truffle.api.utilities;
+
+import com.oracle.truffle.api.*;
+import com.oracle.truffle.api.nodes.*;
+
+/**
+ * An assumption that is always valid. Used as a placeholder where an assumption is needed but never
+ * invalidated.
+ */
+public class AlwaysValidAssumption implements Assumption {
+
+    public static final AlwaysValidAssumption INSTANCE = new AlwaysValidAssumption();
+
+    @Override
+    public void check() throws InvalidAssumptionException {
+    }
+
+    @Override
+    public void invalidate() {
+        throw new UnsupportedOperationException("Cannot invalidation this assumption - it is always valid");
+    }
+
+    @Override
+    public String getName() {
+        return getClass().getName();
+    }
+
+    @Override
+    public boolean isValid() {
+        return true;
+    }
+
+}