--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Jint.Runtime/VM/FunctionBuilder.cs	Wed Oct 30 20:44:42 2013 +0400
@@ -0,0 +1,70 @@
+using System;
+using System.Collections.Generic;
+
+namespace Jint.Runtime.VM
+{
+	class FunctionBuidler
+	{
+		Scope m_parentScope;
+
+		/// <summary>
+		/// maps local variable names to the registers
+		/// </summary>
+		Dictionary<string,int> m_locals;
+
+		/// <summary>
+		/// maps formal parameters to local variables
+		/// </summary>
+		int[] m_formalParameters;
+
+		int m_frameSize;
+
+		IInstruction m_code;
+
+		RuntimeContext m_runtime;
+
+		public FunctionBuilder (string[] argumentNames, RuntimeContext runtime, Scope parentScope)
+		{
+			m_parentScope;
+			m_frameSize = 2; // reserve for this and scope
+
+			m_locals = new Dictionary<string,int>();
+
+			if (argumentNames!= null) {
+				m_formalParameters = new int[argumentNames.Length];
+				for(int i = 0; i < argumentNames.Length; i++)
+					m_formalParameters[i] = AllocVariable(argumentNames[i]);
+			}
+		}
+
+		// all vars should be allocated before temp registers
+		public int AllocVariable(string name) {
+			int id;
+
+			if (m_locals.TryGetValue (name, out id))
+				return id;
+
+			id = m_frameSize++;
+			m_locals [name] = id;
+			return id;
+		}
+
+		public int AllocateRegister() {
+			return m_frameSize++;
+		}
+
+		public void Invoke (object that, object[] args) {
+			var frame = new Frame (m_frameSize, m_runtime);
+			var scope = new Scope (m_locals, frame, m_declaringScope);
+			frame.SetValue (Frame.ThisRegister, that);
+			frame.SetValue (Frame.ScopeRegister, scope);
+
+			var paramLen = Math.Min (m_formalParameters.Length, args.Length);
+
+			for (int i=0; i< paramLen; i++)
+				frame.SetValue (m_formalParameters [i], args [i]);
+		}
+
+	}
+}
+