1 files changed, 139 insertions, 0 deletions
diff --git a/runtime/CSharp3/Sources/Antlr3.Runtime.Debug/ParseTreeBuilder.cs b/runtime/CSharp3/Sources/Antlr3.Runtime.Debug/ParseTreeBuilder.cs
new file mode 100644
index 0000000..deeaf3b
--- /dev/null
+++ b/runtime/CSharp3/Sources/Antlr3.Runtime.Debug/ParseTreeBuilder.cs
@@ -0,0 +1,139 @@
+/*
+ * [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.Debug
+{
+    using System.Collections.Generic;
+    using ParseTree = Antlr.Runtime.Tree.ParseTree;
+
+    /** <summary>
+     *  This parser listener tracks rule entry/exit and token matches
+     *  to build a simple parse tree using ParseTree nodes.
+     *  </summary>
+     */
+    public class ParseTreeBuilder : BlankDebugEventListener
+    {
+        public const string EPSILON_PAYLOAD = "<epsilon>";
+
+        Stack<ParseTree> callStack = new Stack<ParseTree>();
+        List<IToken> hiddenTokens = new List<IToken>();
+        int backtracking = 0;
+
+        public ParseTreeBuilder( string grammarName )
+        {
+            ParseTree root = Create( "<grammar " + grammarName + ">" );
+            callStack.Push( root );
+        }
+
+        public virtual ParseTree Tree
+        {
+            get
+            {
+                return callStack.Peek();
+            }
+        }
+
+        /** <summary>
+         *  What kind of node to create.  You might want to override
+         *  so I factored out creation here.
+         *  </summary>
+         */
+        public virtual ParseTree Create( object payload )
+        {
+            return new ParseTree( payload );
+        }
+
+        public virtual ParseTree EpsilonNode()
+        {
+            return Create( EPSILON_PAYLOAD );
+        }
+
+        /** <summary>Backtracking or cyclic DFA, don't want to add nodes to tree</summary> */
+        public override void EnterDecision( int d, bool couldBacktrack )
+        {
+            backtracking++;
+        }
+        public override void ExitDecision( int i )
+        {
+            backtracking--;
+        }
+
+        public override void EnterRule( string filename, string ruleName )
+        {
+            if ( backtracking > 0 )
+                return;
+            ParseTree parentRuleNode = callStack.Peek();
+            ParseTree ruleNode = Create( ruleName );
+            parentRuleNode.AddChild( ruleNode );
+            callStack.Push( ruleNode );
+        }
+
+        public override void ExitRule( string filename, string ruleName )
+        {
+            if ( backtracking > 0 )
+                return;
+            ParseTree ruleNode = callStack.Peek();
+            if ( ruleNode.ChildCount == 0 )
+            {
+                ruleNode.AddChild( EpsilonNode() );
+            }
+            callStack.Pop();
+        }
+
+        public override void ConsumeToken( IToken token )
+        {
+            if ( backtracking > 0 )
+                return;
+            ParseTree ruleNode = callStack.Peek();
+            ParseTree elementNode = Create( token );
+            elementNode.hiddenTokens = this.hiddenTokens;
+            this.hiddenTokens = new List<IToken>();
+            ruleNode.AddChild( elementNode );
+        }
+
+        public override void ConsumeHiddenToken( IToken token )
+        {
+            if ( backtracking > 0 )
+                return;
+            hiddenTokens.Add( token );
+        }
+
+        public override void RecognitionException( RecognitionException e )
+        {
+            if ( backtracking > 0 )
+                return;
+            ParseTree ruleNode = callStack.Peek();
+            ParseTree errorNode = Create( e );
+            ruleNode.AddChild( errorNode );
+        }
+    }
+}