--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.ruby.nodes/src/com/oracle/truffle/ruby/nodes/call/ProcOrNullNode.java	Mon Jan 06 17:12:09 2014 +0000
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2013 Oracle and/or its affiliates. All rights reserved. This
+ * code is released under a tri EPL/GPL/LGPL license. You can use it,
+ * redistribute it and/or modify it under the terms of the:
+ *
+ * Eclipse Public License version 1.0
+ * GNU General Public License version 2
+ * GNU Lesser General Public License version 2.1
+ */
+package com.oracle.truffle.ruby.nodes.call;
+
+import com.oracle.truffle.api.*;
+import com.oracle.truffle.api.dsl.*;
+import com.oracle.truffle.api.frame.*;
+import com.oracle.truffle.api.nodes.*;
+import com.oracle.truffle.ruby.nodes.*;
+import com.oracle.truffle.ruby.runtime.*;
+import com.oracle.truffle.ruby.runtime.core.*;
+
+/**
+ * Wraps some node that will produce either a {@link RubyProc} or a {@link NilPlaceholder} and
+ * returns {@code null} in case of the latter. Used in parts of the dispatch chain.
+ */
+@NodeInfo(shortName = "proc-or-null")
+@NodeChild(value = "child", type = RubyNode.class)
+public abstract class ProcOrNullNode extends RubyNode {
+
+    public ProcOrNullNode(RubyContext context, SourceSection sourceSection) {
+        super(context, sourceSection);
+    }
+
+    public ProcOrNullNode(ProcOrNullNode prev) {
+        super(prev);
+    }
+
+    @Specialization
+    public Object doNil(@SuppressWarnings("unused") NilPlaceholder nil) {
+        return null;
+    }
+
+    @Specialization
+    public Object doProc(RubyProc proc) {
+        return proc;
+    }
+
+    @Override
+    public RubyProc executeRubyProc(VirtualFrame frame) {
+        final Object proc = execute(frame);
+
+        // The standard asRubyProc test doesn't allow for null
+        assert proc == null || RubyTypesGen.RUBYTYPES.isRubyProc(proc);
+
+        return (RubyProc) proc;
+    }
+
+}