1 files changed, 99 insertions, 0 deletions
diff --git a/runtime/CSharp3/Sources/Antlr3.Runtime/Tree/RewriteRuleSubtreeStream.cs b/runtime/CSharp3/Sources/Antlr3.Runtime/Tree/RewriteRuleSubtreeStream.cs
new file mode 100644
index 0000000..504b891
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+++ b/runtime/CSharp3/Sources/Antlr3.Runtime/Tree/RewriteRuleSubtreeStream.cs
@@ -0,0 +1,99 @@
+/*
+ * [The "BSD licence"]
+ * Copyright (c) 2005-2008 Terence Parr
+ * All rights reserved.
+ *
+ * Conversion to C#:
+ * Copyright (c) 2008-2009 Sam Harwell, Pixel Mine, Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+namespace Antlr.Runtime.Tree
+{
+    using IList = System.Collections.IList;
+
+    [System.Serializable]
+    public class RewriteRuleSubtreeStream : RewriteRuleElementStream
+    {
+        public RewriteRuleSubtreeStream( ITreeAdaptor adaptor, string elementDescription )
+            : base( adaptor, elementDescription )
+        {
+        }
+
+        /** <summary>Create a stream with one element</summary> */
+        public RewriteRuleSubtreeStream( ITreeAdaptor adaptor, string elementDescription, object oneElement )
+            : base( adaptor, elementDescription, oneElement )
+        {
+        }
+
+        /** <summary>Create a stream, but feed off an existing list</summary> */
+        public RewriteRuleSubtreeStream( ITreeAdaptor adaptor, string elementDescription, IList elements )
+            : base( adaptor, elementDescription, elements )
+        {
+        }
+
+        /** <summary>
+         *  Treat next element as a single node even if it's a subtree.
+         *  This is used instead of next() when the result has to be a
+         *  tree root node.  Also prevents us from duplicating recently-added
+         *  children; e.g., ^(type ID)+ adds ID to type and then 2nd iteration
+         *  must dup the type node, but ID has been added.
+         *  </summary>
+         *
+         *  <remarks>
+         *  Referencing a rule result twice is ok; dup entire tree as
+         *  we can't be adding trees as root; e.g., expr expr.
+         *
+         *  Hideous code duplication here with super.next().  Can't think of
+         *  a proper way to refactor.  This needs to always call dup node
+         *  and super.next() doesn't know which to call: dup node or dup tree.
+         *  </remarks>
+         */
+        public virtual object NextNode()
+        {
+            //System.Console.WriteLine("nextNode: elements={0}, singleElement={1}", elements, ((ITree)singleElement).ToStringTree());
+            int n = Count;
+            if ( dirty || ( cursor >= n && n == 1 ) )
+            {
+                // if out of elements and size is 1, dup (at most a single node
+                // since this is for making root nodes).
+                object el = NextCore();
+                return adaptor.DupNode( el );
+            }
+            // test size above then fetch
+            object tree = NextCore();
+            while (adaptor.IsNil(tree) && adaptor.GetChildCount(tree) == 1)
+                tree = adaptor.GetChild(tree, 0);
+            //System.Console.WriteLine("_next={0}", ((ITree)tree).ToStringTree());
+            object el2 = adaptor.DupNode(tree); // dup just the root (want node here)
+            return el2;
+        }
+
+        protected override object Dup( object el )
+        {
+            return adaptor.DupTree( el );
+        }
+    }
+}