WSHCommon/Common/Library/ulua/C#/uLua/LuaInterface/Metatables.cs

namespace LuaInterface
{
	using System;
	using System.IO;
	using System.Collections;
	using System.Reflection;
	using System.Diagnostics;
	using System.Collections.Generic;
	using System.Runtime.InteropServices;
	
	/*
     * Functions used in the metatables of userdata representing
     * CLR objects
     *
     * Author: Fabio Mascarenhas
     * Version: 1.0
     */
	public class MetaFunctions
	{
		/*
         * __index metafunction for CLR objects. Implemented in Lua.
         */
		internal static string luaIndexFunction =
			@"
        local function index(obj,name)
        local meta=getmetatable(obj)
        local cached=meta.cache[name]
        if cached then
           return cached
        else
           local value,isFunc = get_object_member(obj,name)
           if value==nil and type(isFunc)=='string' then error(isFunc,2) end
           if isFunc then
            meta.cache[name]=value
           end
           return value
         end
    end
    return index";
		
		private ObjectTranslator translator;
		private Hashtable memberCache = new Hashtable();
		internal LuaCSFunction gcFunction, indexFunction, newindexFunction,
		baseIndexFunction, classIndexFunction, classNewindexFunction,
		execDelegateFunction, callConstructorFunction, toStringFunction;
		
		public MetaFunctions(ObjectTranslator translator)
		{
			this.translator = translator;
			gcFunction = new LuaCSFunction(collectObject);
			toStringFunction = new LuaCSFunction(toString);
			indexFunction = new LuaCSFunction(getMethod);
			newindexFunction = new LuaCSFunction(setFieldOrProperty);
			baseIndexFunction = new LuaCSFunction(getBaseMethod);
			callConstructorFunction = new LuaCSFunction(callConstructor);
			classIndexFunction = new LuaCSFunction(getClassMethod);
			classNewindexFunction = new LuaCSFunction(setClassFieldOrProperty);
			execDelegateFunction = new LuaCSFunction(runFunctionDelegate);
		}
		
		/*
         * __call metafunction of CLR delegates, retrieves and calls the delegate.
         */
		[MonoPInvokeCallbackAttribute(typeof(LuaCSFunction))]
		public static int runFunctionDelegate(IntPtr luaState)
		{
			ObjectTranslator translator = ObjectTranslator.FromState(luaState);
			LuaCSFunction func = (LuaCSFunction)translator.getRawNetObject(luaState, 1);
			LuaDLL.lua_remove(luaState, 1);
			return func(luaState);
		}
		/*
         * __gc metafunction of CLR objects.
         */
		
		[MonoPInvokeCallbackAttribute(typeof(LuaCSFunction))]
		public static int collectObject(IntPtr luaState)
		{
			int udata = LuaDLL.luanet_rawnetobj(luaState, 1);
			if (udata != -1)
			{
				ObjectTranslator translator = ObjectTranslator.FromState(luaState);
				translator.collectObject(udata);
			}
			else
			{
				// Debug.WriteLine("not found: " + udata);
			}
			return 0;
		}
		/*
         * __tostring metafunction of CLR objects.
         */
		[MonoPInvokeCallbackAttribute(typeof(LuaCSFunction))]
		public static int toString(IntPtr luaState)
		{
			ObjectTranslator translator = ObjectTranslator.FromState(luaState);
			object obj = translator.getRawNetObject(luaState, 1);
			if (obj != null)
			{
				translator.push(luaState, obj.ToString() + ": " + obj.GetHashCode());
			}
			else LuaDLL.lua_pushnil(luaState);
			return 1;
		}
		
		
		/// <summary>
		/// Debug tool to dump the lua stack
		/// </summary>
		/// FIXME, move somewhere else
		public static void dumpStack(ObjectTranslator translator, IntPtr luaState)
		{
			int depth = LuaDLL.lua_gettop(luaState);
			
			Debug.WriteLine("lua stack depth: " + depth);
			for (int i = 1; i <= depth; i++)
			{
				LuaTypes type = LuaDLL.lua_type(luaState, i);
				// we dump stacks when deep in calls, calling typename while the stack is in flux can fail sometimes, so manually check for key types
				string typestr = (type == LuaTypes.LUA_TTABLE) ? "table" : LuaDLL.lua_typename(luaState, type);
				
				string strrep = LuaDLL.lua_tostring(luaState, i);
				if (type == LuaTypes.LUA_TUSERDATA)
				{
					object obj = translator.getRawNetObject(luaState, i);
					strrep = obj.ToString();
				}
				
				Debug.WriteLine(String.Format("{0}: ({1}) {2}", i, typestr, strrep));
			}
		}
		
		/*
         * Called by the __index metafunction of CLR objects in case the
         * method is not cached or it is a field/property/event.
         * Receives the object and the member name as arguments and returns
         * either the value of the member or a delegate to call it.
         * If the member does not exist returns nil.
         */
		[MonoPInvokeCallbackAttribute(typeof(LuaCSFunction))]
		public static int getMethod(IntPtr luaState)
		{
			ObjectTranslator translator = ObjectTranslator.FromState(luaState);
			object obj = translator.getRawNetObject(luaState, 1);
			if (obj == null)
			{
				translator.throwError(luaState, "trying to index an invalid object reference");
				LuaDLL.lua_pushnil(luaState);
				return 1;
			}
			
			object index = translator.getObject(luaState, 2);
			//Type indexType = index.GetType(); //* not used
			
			string methodName = index as string;        // will be null if not a string arg
			Type objType = obj.GetType();
			
			// Handle the most common case, looking up the method by name.
			
			// CP: This will fail when using indexers and attempting to get a value with the same name as a property of the object,
			// ie: xmlelement['item'] <- item is a property of xmlelement
			try
			{
				if (methodName != null && translator.metaFunctions.isMemberPresent(objType, methodName))
					return translator.metaFunctions.getMember(luaState, objType, obj, methodName, BindingFlags.Instance | BindingFlags.IgnoreCase);
			}
			catch { }
			bool failed = true;
			
			// Try to access by array if the type is right and index is an int (lua numbers always come across as double)
			if (objType.IsArray && index is double)
			{
				int intIndex = (int)((double)index);
				Array aa = obj as Array;
				if (intIndex >= aa.Length) {
					return translator.pushError(luaState,"array index out of bounds: "+intIndex + " " + aa.Length);
				}
				object val = aa.GetValue(intIndex);
				translator.push (luaState,val);
				failed = false;
			}
			else
			{
				// Try to use get_Item to index into this .net object
				//MethodInfo getter = objType.GetMethod("get_Item");
				// issue here is that there may be multiple indexers..
				MethodInfo[] methods = objType.GetMethods();
				
				foreach (MethodInfo mInfo in methods)
				{
					if (mInfo.Name == "get_Item")
					{
						//check if the signature matches the input
						if (mInfo.GetParameters().Length == 1)
						{
							MethodInfo getter = mInfo;
							ParameterInfo[] actualParms = (getter != null) ? getter.GetParameters() : null;
							if (actualParms == null || actualParms.Length != 1)
							{
								return translator.pushError(luaState, "method not found (or no indexer): " + index);
							}
							else
							{
								// Get the index in a form acceptable to the getter
								index = translator.getAsType(luaState, 2, actualParms[0].ParameterType);
								// Just call the indexer - if out of bounds an exception will happen
								try
								{
									object result = getter.Invoke(obj, new object[]{index});
									translator.push(luaState, result);
									failed = false;
								}
								catch (TargetInvocationException e)
								{
									// Provide a more readable description for the common case of key not found
									if (e.InnerException is KeyNotFoundException)
										return translator.pushError(luaState, "key '" + index + "' not found ");
									else
										return translator.pushError(luaState, "exception indexing '" + index + "' " + e.Message);
									
									
								}
							}
						}
					}
				}
				
				
			}
			if (failed) {
				return translator.pushError(luaState,"cannot find " + index);
			}
			LuaDLL.lua_pushboolean(luaState, false);
			return 2;
		}
		
		
		/*
         * __index metafunction of base classes (the base field of Lua tables).
         * Adds a prefix to the method name to call the base version of the method.
         */
		[MonoPInvokeCallbackAttribute(typeof(LuaCSFunction))]
		public static int getBaseMethod(IntPtr luaState)
		{
			ObjectTranslator translator = ObjectTranslator.FromState(luaState);
			object obj = translator.getRawNetObject(luaState, 1);
			if (obj == null)
			{
				translator.throwError(luaState, "trying to index an invalid object reference");
				LuaDLL.lua_pushnil(luaState);
				LuaDLL.lua_pushboolean(luaState, false);
				return 2;
			}
			string methodName = LuaDLL.lua_tostring(luaState, 2);
			if (methodName == null)
			{
				LuaDLL.lua_pushnil(luaState);
				LuaDLL.lua_pushboolean(luaState, false);
				return 2;
			}
			translator.metaFunctions.getMember(luaState, obj.GetType(), obj, "__luaInterface_base_" + methodName, BindingFlags.Instance | BindingFlags.IgnoreCase);
			LuaDLL.lua_settop(luaState, -2);
			if (LuaDLL.lua_type(luaState, -1) == LuaTypes.LUA_TNIL)
			{
				LuaDLL.lua_settop(luaState, -2);
				return translator.metaFunctions.getMember(luaState, obj.GetType(), obj, methodName, BindingFlags.Instance | BindingFlags.IgnoreCase);
			}
			LuaDLL.lua_pushboolean(luaState, false);
			return 2;
		}
		
		
		/// <summary>
		/// Does this method exist as either an instance or static?
		/// </summary>
		/// <param name="objType"></param>
		/// <param name="methodName"></param>
		/// <returns></returns>
		bool isMemberPresent(IReflect objType, string methodName)
		{
			object cachedMember = checkMemberCache(memberCache, objType, methodName);
			
			if (cachedMember != null)
				return true;
			
			//CP: Removed NonPublic binding search
			MemberInfo[] members = objType.GetMember(methodName, BindingFlags.Static | BindingFlags.Instance | BindingFlags.Public | BindingFlags.IgnoreCase/* | BindingFlags.NonPublic*/);
			return (members.Length > 0);
		}
		
		/*
         * Pushes the value of a member or a delegate to call it, depending on the type of
         * the member. Works with static or instance members.
         * Uses reflection to find members, and stores the reflected MemberInfo object in
         * a cache (indexed by the type of the object and the name of the member).
         */
		private int getMember(IntPtr luaState, IReflect objType, object obj, string methodName, BindingFlags bindingType)
		{
			bool implicitStatic = false;
			MemberInfo member = null;
			object cachedMember = checkMemberCache(memberCache, objType, methodName);
			//object cachedMember=null;
			if (cachedMember is LuaCSFunction)
			{
				translator.pushFunction(luaState, (LuaCSFunction)cachedMember);
				translator.push(luaState, true);
				return 2;
			}
			else if (cachedMember != null)
			{
				member = (MemberInfo)cachedMember;
			}
			else
			{
				//CP: Removed NonPublic binding search
				MemberInfo[] members = objType.GetMember(methodName, bindingType | BindingFlags.Public | BindingFlags.IgnoreCase/*| BindingFlags.NonPublic*/);
				if (members.Length > 0)
					member = members[0];
				else
				{
					// If we can't find any suitable instance members, try to find them as statics - but we only want to allow implicit static
					// lookups for fields/properties/events -kevinh
					//CP: Removed NonPublic binding search and made case insensitive
					members = objType.GetMember(methodName, bindingType | BindingFlags.Static | BindingFlags.Public | BindingFlags.IgnoreCase/*| BindingFlags.NonPublic*/);
					
					if (members.Length > 0)
					{
						member = members[0];
						implicitStatic = true;
					}
				}
			}
			if (member != null)
			{
				if (member.MemberType == MemberTypes.Field)
				{
					FieldInfo field = (FieldInfo)member;
					if (cachedMember == null) setMemberCache(memberCache, objType, methodName, member);
					try
					{
						translator.push(luaState, field.GetValue(obj));
					}
					catch
					{
						LuaDLL.lua_pushnil(luaState);
					}
				}
				else if (member.MemberType == MemberTypes.Property)
				{
					PropertyInfo property = (PropertyInfo)member;
					if (cachedMember == null) setMemberCache(memberCache, objType, methodName, member);
					try
					{
						object val = property.GetValue(obj, null);
						
						translator.push(luaState, val);
					}
					catch (ArgumentException)
					{
						// If we can't find the getter in our class, recurse up to the base class and see
						// if they can help.
						
						if (objType is Type && !(((Type)objType) == typeof(object)))
							return getMember(luaState, ((Type)objType).BaseType, obj, methodName, bindingType);
						else
							LuaDLL.lua_pushnil(luaState);
					}
					catch (TargetInvocationException e)  // Convert this exception into a Lua error
					{
						ThrowError(luaState, e);
						LuaDLL.lua_pushnil(luaState);
					}
				}
				else if (member.MemberType == MemberTypes.Event)
				{
					EventInfo eventInfo = (EventInfo)member;
					if (cachedMember == null) setMemberCache(memberCache, objType, methodName, member);
					translator.push(luaState, new RegisterEventHandler(translator.pendingEvents, obj, eventInfo));
				}
				else if (!implicitStatic)
				{
					if (member.MemberType == MemberTypes.NestedType)
					{
						// kevinh - added support for finding nested types
						
						// cache us
						if (cachedMember == null) setMemberCache(memberCache, objType, methodName, member);
						
						// Find the name of our class
						string name = member.Name;
						Type dectype = member.DeclaringType;
						
						// Build a new long name and try to find the type by name
						string longname = dectype.FullName + "+" + name;
						Type nestedType = translator.FindType(longname);
						
						translator.pushType(luaState, nestedType);
					}
					else
					{
						// Member type must be 'method'
						LuaCSFunction wrapper = new LuaCSFunction((new LuaMethodWrapper(translator, objType, methodName, bindingType)).call);
						
						if (cachedMember == null) setMemberCache(memberCache, objType, methodName, wrapper);
						translator.pushFunction(luaState, wrapper);
						translator.push(luaState, true);
						return 2;
					}
				}
				else
				{
					// If we reach this point we found a static method, but can't use it in this context because the user passed in an instance
					translator.throwError(luaState, "can't pass instance to static method " + methodName);
					
					LuaDLL.lua_pushnil(luaState);
				}
			}
			else
			{
				// kevinh - we want to throw an exception because meerly returning 'nil' in this case
				// is not sufficient.  valid data members may return nil and therefore there must be some
				// way to know the member just doesn't exist.
				
				translator.throwError(luaState, "unknown member name " + methodName);
				
				LuaDLL.lua_pushnil(luaState);
			}
			
			// push false because we are NOT returning a function (see luaIndexFunction)
			translator.push(luaState, false);
			return 2;
		}
		/*
         * Checks if a MemberInfo object is cached, returning it or null.
         */
		private object checkMemberCache(Hashtable memberCache, IReflect objType, string memberName)
		{
			Hashtable members = (Hashtable)memberCache[objType];
			if (members != null)
				return members[memberName];
			else
				return null;
		}
		/*
         * Stores a MemberInfo object in the member cache.
         */
		private void setMemberCache(Hashtable memberCache, IReflect objType, string memberName, object member)
		{
			Hashtable members = (Hashtable)memberCache[objType];
			if (members == null)
			{
				members = new Hashtable();
				memberCache[objType] = members;
			}
			members[memberName] = member;
		}
		/*
         * __newindex metafunction of CLR objects. Receives the object,
         * the member name and the value to be stored as arguments. Throws
         * and error if the assignment is invalid.
         */
		[MonoPInvokeCallbackAttribute(typeof(LuaCSFunction))]
		public static int setFieldOrProperty(IntPtr luaState)
		{
			ObjectTranslator translator = ObjectTranslator.FromState(luaState);
			object target = translator.getRawNetObject(luaState, 1);
			if (target == null)
			{
				translator.throwError(luaState, "trying to index and invalid object reference");
				return 0;
			}
			Type type = target.GetType();
			
			// First try to look up the parameter as a property name
			string detailMessage;
			bool didMember = translator.metaFunctions.trySetMember(luaState, type, target, BindingFlags.Instance | BindingFlags.IgnoreCase, out detailMessage);
			
			if (didMember)
				return 0;       // Must have found the property name
			
			// We didn't find a property name, now see if we can use a [] style this accessor to set array contents
			try
			{
				if (type.IsArray && LuaDLL.lua_isnumber(luaState, 2))
				{
					int index = (int)LuaDLL.lua_tonumber(luaState, 2);
					
					Array arr = (Array)target;
					object val = translator.getAsType(luaState, 3, arr.GetType().GetElementType());
					arr.SetValue(val, index);
				}
				else
				{
					// Try to see if we have a this[] accessor
					MethodInfo setter = type.GetMethod("set_Item");
					if (setter != null)
					{
						ParameterInfo[] args = setter.GetParameters();
						Type valueType = args[1].ParameterType;
						
						// The new val ue the user specified
						object val = translator.getAsType(luaState, 3, valueType);
						
						Type indexType = args[0].ParameterType;
						object index = translator.getAsType(luaState, 2, indexType);
						
						object[] methodArgs = new object[2];
						
						// Just call the indexer - if out of bounds an exception will happen
						methodArgs[0] = index;
						methodArgs[1] = val;
						
						setter.Invoke(target, methodArgs);
					}
					else
					{
						translator.throwError(luaState, detailMessage); // Pass the original message from trySetMember because it is probably best
					}
				}
			}
			catch (SEHException)
			{
				// If we are seeing a C++ exception - this must actually be for Lua's private use.  Let it handle it
				throw;
			}
			catch (Exception e)
			{
				translator.metaFunctions.ThrowError(luaState, e);
			}
			return 0;
		}
		
		/// <summary>
		/// Tries to set a named property or field
		/// </summary>
		/// <param name="luaState"></param>
		/// <param name="targetType"></param>
		/// <param name="target"></param>
		/// <param name="bindingType"></param>
		/// <returns>false if unable to find the named member, true for success</returns>
		private bool trySetMember(IntPtr luaState, IReflect targetType, object target, BindingFlags bindingType, out string detailMessage)
		{
			detailMessage = null;   // No error yet
			
			// If not already a string just return - we don't want to call tostring - which has the side effect of
			// changing the lua typecode to string
			// Note: We don't use isstring because the standard lua C isstring considers either strings or numbers to
			// be true for isstring.
			if (LuaDLL.lua_type(luaState, 2) != LuaTypes.LUA_TSTRING)
			{
				detailMessage = "property names must be strings";
				return false;
			}
			
			// We only look up property names by string
			string fieldName = LuaDLL.lua_tostring(luaState, 2);
			if (fieldName == null || fieldName.Length < 1 || !(char.IsLetter(fieldName[0]) || fieldName[0] == '_'))
			{
				detailMessage = "invalid property name";
				return false;
			}
			
			// Find our member via reflection or the cache
			MemberInfo member = (MemberInfo)checkMemberCache(memberCache, targetType, fieldName);
			if (member == null)
			{
				//CP: Removed NonPublic binding search and made case insensitive
				MemberInfo[] members = targetType.GetMember(fieldName, bindingType | BindingFlags.Public | BindingFlags.IgnoreCase/*| BindingFlags.NonPublic*/);
				if (members.Length > 0)
				{
					member = members[0];
					setMemberCache(memberCache, targetType, fieldName, member);
				}
				else
				{
					detailMessage = "field or property '" + fieldName + "' does not exist";
					return false;
				}
			}
			
			if (member.MemberType == MemberTypes.Field)
			{
				FieldInfo field = (FieldInfo)member;
				object val = translator.getAsType(luaState, 3, field.FieldType);
				try
				{
					field.SetValue(target, val);
				}
				catch (Exception e)
				{
					ThrowError(luaState, e);
				}
				// We did a call
				return true;
			}
			else if (member.MemberType == MemberTypes.Property)
			{
				PropertyInfo property = (PropertyInfo)member;
				object val = translator.getAsType(luaState, 3, property.PropertyType);
				try
				{
					property.SetValue(target, val, null);
				}
				catch (Exception e)
				{
					ThrowError(luaState, e);
				}
				// We did a call
				return true;
			}
			
			detailMessage = "'" + fieldName + "' is not a .net field or property";
			return false;
		}
		
		
		/*
         * Writes to fields or properties, either static or instance. Throws an error
         * if the operation is invalid.
         */
		private int setMember(IntPtr luaState, IReflect targetType, object target, BindingFlags bindingType)
		{
			string detail;
			bool success = trySetMember(luaState, targetType, target, bindingType, out detail);
			
			if (!success)
				translator.throwError(luaState, detail);
			
			return 0;
		}
		
		/// <summary>
		/// Convert a C# exception into a Lua error
		/// </summary>
		/// <param name="e"></param>
		/// We try to look into the exception to give the most meaningful description
		void ThrowError(IntPtr luaState, Exception e)
		{
			// If we got inside a reflection show what really happened
			TargetInvocationException te = e as TargetInvocationException;
			
			if (te != null)
				e = te.InnerException;
			
			translator.throwError(luaState, e);
		}
		
		/*
         * __index metafunction of type references, works on static members.
         */
		[MonoPInvokeCallbackAttribute(typeof(LuaCSFunction))]
		public static int getClassMethod(IntPtr luaState)
		{
			ObjectTranslator translator = ObjectTranslator.FromState(luaState);
			IReflect klass;
			object obj = translator.getRawNetObject(luaState, 1);
			if (obj == null || !(obj is IReflect))
			{
				translator.throwError(luaState, "trying to index an invalid type reference");
				LuaDLL.lua_pushnil(luaState);
				return 1;
			}
			else klass = (IReflect)obj;
			if (LuaDLL.lua_isnumber(luaState, 2))
			{
				int size = (int)LuaDLL.lua_tonumber(luaState, 2);
				translator.push(luaState, Array.CreateInstance(klass.UnderlyingSystemType, size));
				return 1;
			}
			else
			{
				string methodName = LuaDLL.lua_tostring(luaState, 2);
				if (methodName == null)
				{
					LuaDLL.lua_pushnil(luaState);
					return 1;
				} //CP: Ignore case
				else return translator.metaFunctions.getMember(luaState, klass, null, methodName, BindingFlags.FlattenHierarchy | BindingFlags.Static | BindingFlags.IgnoreCase);
			}
		}
		/*
         * __newindex function of type references, works on static members.
         */
		[MonoPInvokeCallbackAttribute(typeof(LuaCSFunction))]
		public static int setClassFieldOrProperty(IntPtr luaState)
		{
			ObjectTranslator translator = ObjectTranslator.FromState(luaState);
			IReflect target;
			object obj = translator.getRawNetObject(luaState, 1);
			if (obj == null || !(obj is IReflect))
			{
				translator.throwError(luaState, "trying to index an invalid type reference");
				return 0;
			}
			else target = (IReflect)obj;
			return translator.metaFunctions.setMember(luaState, target, null, BindingFlags.FlattenHierarchy | BindingFlags.Static | BindingFlags.IgnoreCase);
		}
		/*
         * __call metafunction of type references. Searches for and calls
         * a constructor for the type. Returns nil if the constructor is not
         * found or if the arguments are invalid. Throws an error if the constructor
         * generates an exception.
         */
		[MonoPInvokeCallbackAttribute(typeof(LuaCSFunction))]
		public static int callConstructor(IntPtr luaState)
		{
			ObjectTranslator translator = ObjectTranslator.FromState(luaState);
			MethodCache validConstructor = new MethodCache();
			IReflect klass;
			object obj = translator.getRawNetObject(luaState, 1);
			if (obj == null || !(obj is IReflect))
			{
				translator.throwError(luaState, "trying to call constructor on an invalid type reference");
				LuaDLL.lua_pushnil(luaState);
				return 1;
			}
			else klass = (IReflect)obj;
			LuaDLL.lua_remove(luaState, 1);
			ConstructorInfo[] constructors = klass.UnderlyingSystemType.GetConstructors();
			foreach (ConstructorInfo constructor in constructors)
			{
				bool isConstructor = translator.metaFunctions.matchParameters(luaState, constructor, ref validConstructor);
				if (isConstructor)
				{
					try
					{
						translator.push(luaState, constructor.Invoke(validConstructor.args));
					}
					catch (TargetInvocationException e)
					{
						translator.metaFunctions.ThrowError(luaState, e);
						LuaDLL.lua_pushnil(luaState);
					}
					catch
					{
						LuaDLL.lua_pushnil(luaState);
					}
					return 1;
				}
			}
			
			string constructorName = (constructors.Length == 0) ? "unknown" : constructors[0].Name;
			
			translator.throwError(luaState, String.Format("{0} does not contain constructor({1}) argument match",
			                                              klass.UnderlyingSystemType,
			                                              constructorName));
			LuaDLL.lua_pushnil(luaState);
			return 1;
		}
		
		private static bool IsInteger(double x) {
			return Math.Ceiling(x) == x;	
		}			
		
		
		internal Array TableToArray(object luaParamValue, Type paramArrayType) {
			Array paramArray;
			
			if (luaParamValue is LuaTable)  {
				LuaTable table = (LuaTable)luaParamValue;
				IDictionaryEnumerator tableEnumerator = table.GetEnumerator();				
				tableEnumerator.Reset();
				paramArray = Array.CreateInstance(paramArrayType, table.Values.Count);                
				
				int paramArrayIndex = 0;
				
				while(tableEnumerator.MoveNext())  {
					object o = tableEnumerator.Value;
					if (paramArrayType == typeof(object)) { 
						if (o != null && o.GetType() == typeof(double) && IsInteger((double)o))
							o = Convert.ToInt32((double)o);
					}													
					paramArray.SetValue(Convert.ChangeType(o, paramArrayType), paramArrayIndex);
					paramArrayIndex++;
				}
			} else {
				paramArray = Array.CreateInstance(paramArrayType, 1);
				paramArray.SetValue(luaParamValue, 0);
			}
			
			return paramArray;
			
		}
		
		/*
         * Matches a method against its arguments in the Lua stack. Returns
         * if the match was succesful. It it was also returns the information
         * necessary to invoke the method.
         */
		internal bool matchParameters(IntPtr luaState, MethodBase method, ref MethodCache methodCache)
		{
			ExtractValue extractValue;
			bool isMethod = true;
			ParameterInfo[] paramInfo = method.GetParameters();
			int currentLuaParam = 1;
			int nLuaParams = LuaDLL.lua_gettop(luaState);
			ArrayList paramList = new ArrayList();
			List<int> outList = new List<int>();
			List<MethodArgs> argTypes = new List<MethodArgs>();
			foreach (ParameterInfo currentNetParam in paramInfo)
			{
				if (!currentNetParam.IsIn && currentNetParam.IsOut)  // Skips out params
				{
					outList.Add(paramList.Add(null));
				}
				else if (currentLuaParam > nLuaParams) // Adds optional parameters
				{
					if (currentNetParam.IsOptional)
					{
						paramList.Add(currentNetParam.DefaultValue);
					}
					else
					{
						isMethod = false;
						break;
					}
				}
				else if (_IsTypeCorrect(luaState, currentLuaParam, currentNetParam, out extractValue))  // Type checking
				{
					int index = paramList.Add(extractValue(luaState, currentLuaParam));
					
					MethodArgs methodArg = new MethodArgs();
					methodArg.index = index;
					methodArg.extractValue = extractValue;
					argTypes.Add(methodArg);
					
					if (currentNetParam.ParameterType.IsByRef)
						outList.Add(index);
					currentLuaParam++;
				}  // Type does not match, ignore if the parameter is optional
				else if (_IsParamsArray(luaState, currentLuaParam, currentNetParam, out extractValue))
				{
					object luaParamValue = extractValue(luaState, currentLuaParam);
					Type paramArrayType = currentNetParam.ParameterType.GetElementType();
					
					Array paramArray = TableToArray(luaParamValue, paramArrayType);					
					int index = paramList.Add(paramArray);
					
					MethodArgs methodArg = new MethodArgs();
					methodArg.index = index;
					methodArg.extractValue = extractValue;
					methodArg.isParamsArray = true;
					methodArg.paramsArrayType = paramArrayType;
					argTypes.Add(methodArg);
					
					currentLuaParam++;
				}
				else if (currentNetParam.IsOptional)
				{
					paramList.Add(currentNetParam.DefaultValue);
				}
				else  // No match
				{
					isMethod = false;
					break;
				}
			}
			if (currentLuaParam != nLuaParams + 1) // Number of parameters does not match
				isMethod = false;
			if (isMethod)
			{
				methodCache.args = paramList.ToArray();
				methodCache.cachedMethod = method;
				methodCache.outList = outList.ToArray();
				methodCache.argTypes = argTypes.ToArray();
			}
			return isMethod;
		}
		
		/// <summary>
		/// CP: Fix for operator overloading failure
		/// Returns true if the type is set and assigns the extract value
		/// </summary>
		/// <param name="luaState"></param>
		/// <param name="currentLuaParam"></param>
		/// <param name="currentNetParam"></param>
		/// <param name="extractValue"></param>
		/// <returns></returns>
		private bool _IsTypeCorrect(IntPtr luaState, int currentLuaParam, ParameterInfo currentNetParam, out ExtractValue extractValue)
		{
			try
			{
				return (extractValue = translator.typeChecker.checkType(luaState, currentLuaParam, currentNetParam.ParameterType)) != null;
			}
			catch
			{
				extractValue = null;
				Debug.WriteLine("Type wasn't correct");
				return false;
			}
		}
		
		private bool _IsParamsArray(IntPtr luaState, int currentLuaParam, ParameterInfo currentNetParam, out ExtractValue extractValue)
		{
			extractValue = null;
			
			if (currentNetParam.GetCustomAttributes(typeof(ParamArrayAttribute), false).Length > 0)
			{
				LuaTypes luaType;
				
				try
				{
					luaType = LuaDLL.lua_type(luaState, currentLuaParam);
				}
				catch (Exception ex)
				{
					Debug.WriteLine("Could not retrieve lua type while attempting to determine params Array Status."+ ex.ToString());
					Debug.WriteLine(ex.Message);
					extractValue = null;
					return false;
				}
				
				if (luaType == LuaTypes.LUA_TTABLE)
				{
					try
					{
						extractValue = translator.typeChecker.getExtractor(typeof(LuaTable));
					}
					catch (Exception ex)
					{
						Debug.WriteLine("An error occurred during an attempt to retrieve a LuaTable extractor while checking for params array status." + ex.ToString());
					}
					
					if (extractValue != null)
					{
						return true;
					}
				}
				else
				{
					Type paramElementType = currentNetParam.ParameterType.GetElementType();
					
					try
					{
						extractValue = translator.typeChecker.checkType(luaState, currentLuaParam, paramElementType);
					}
					catch (Exception ex)
					{
						Debug.WriteLine(string.Format("An error occurred during an attempt to retrieve an extractor ({0}) while checking for params array status:{1}", paramElementType.FullName,ex.ToString()));
					}
					
					if (extractValue != null)
					{
						return true;
					}
				}
			}
			
			Debug.WriteLine("Type wasn't Params object.");
			
			return false;
		}
	}
}