X-Git-Url: https://git.dogcows.com/gitweb?p=chaz%2Fyoink;a=blobdiff_plain;f=src%2Fmoof%2Fscript.hh;h=79412acb3bb4b9526d782d54dca8699676621100;hp=85973dd0402f1823434ced4b2da57305b046146d;hb=574af38ed616d1adfa5e6ce35f67cda1f707f89d;hpb=831f04d4bc19a390415ac0bbac4331c7a65509bc

diff --git a/src/moof/script.hh b/src/moof/script.hh
index 85973dd..79412ac 100644
--- a/src/moof/script.hh
+++ b/src/moof/script.hh
@@ -1,31 +1,32 @@
 
-/*]  Copyright (c) 2009-2010, Charles McGarvey  [**************************
+/*]  Copyright (c) 2009-2011, Charles McGarvey  [*****************************
 **]  All rights reserved.
 *
-* vi:ts=4 sw=4 tw=75
-*
 * Distributable under the terms and conditions of the 2-clause BSD license;
 * see the file COPYING for a complete text of the license.
 *
-**************************************************************************/
+*****************************************************************************/
 
 #ifndef _MOOF_SCRIPT_HH_
 #define _MOOF_SCRIPT_HH_
 
 /**
  * \file script.hh
- * A thin wrapper over Lua.  This is not meant as a complicated binding
+ * A thin wrapper over Lua 5.1.  This is not meant as a complicated binding
  * package between C++ and Lua.  It is not meant to obscure the division
- * between C++ and Lua but rather to clarify it and make it more
- * manageable.  It does not hide the concept of the Lua stack, but rather
- * provides that mechanism with a certain level of abstraction while also
- * providing a cleaner, more consistent API.
+ * between C++ and Lua but rather to clarify it and make it more manageable.
+ * It does not hide the concept of the Lua stack, but rather provides that
+ * mechanism with a certain level of abstraction while also providing a
+ * cleaner, more consistent API.
  */
 
+#include <cstring>
 #include <iostream>
-#include <list>
 #include <map>
+#include <stdexcept>
 #include <string>
+#include <sstream>
+#include <utility>
 #include <vector>
 
 #include <boost/bind.hpp>
@@ -40,22 +41,22 @@ namespace moof {
 class script;
 typedef boost::shared_ptr<script> script_ptr;
 
-
 class script
 {
 public:
 
 	typedef boost::function<int(script&)> function;
+	typedef int (*cfunction)(script&);
 
 	enum status
 	{
-		success			= 0,
-		yielding		= LUA_YIELD,
+		success		= 0,
+		yielding	= LUA_YIELD,
 		runtime_error	= LUA_ERRRUN,
 		syntax_error	= LUA_ERRSYNTAX,
 		memory_error	= LUA_ERRMEM,
 		handler_error	= LUA_ERRERR,
-		file_error		= LUA_ERRFILE
+		file_error	= LUA_ERRFILE
 	};
 
 	enum pseudoindex
@@ -65,227 +66,273 @@ public:
 		globals_index		= LUA_GLOBALSINDEX
 	};
 
+	template <class T>
+	static int object_finalizer(script& script)
+	{
+		reinterpret_cast<T*>(script[1].get_data())->~T();
+		return 0;
+	}
+
 	/**
 	 * This is the most prominent abstraction on top of the standard Lua
 	 * API.  A slot object represents a value on the stack.  More
 	 * specifically, it represents a position on the stack.  The
 	 * distinction is only important when objects are moved around on the
 	 * stack or if the slot represents a negative index on the stack (the
-	 * value of which will change as things are pushed onto and popped from
-	 * the stack).
+	 * value of which will change as things are pushed onto and popped
+	 * from the stack).
 	 */
-
 	struct slot
 	{
 		/**
-		 * You have direct access to the index of the value on the stack
-		 * being represented.
+		 * You have direct access to the index of the value on the
+		 * stack being represented.
 		 */
-
 		int index;
 
-
 		enum type
 		{
-			none			= LUA_TNONE,
-			nil				= LUA_TNIL,
-			boolean			= LUA_TBOOLEAN,
-			light_data		= LUA_TLIGHTUSERDATA,
-			number			= LUA_TNUMBER,
-			string			= LUA_TSTRING,
-			table			= LUA_TTABLE,
-			function		= LUA_TFUNCTION,
-			data			= LUA_TUSERDATA,
-			thread			= LUA_TTHREAD
+			none		= LUA_TNONE,
+			nil		= LUA_TNIL,
+			boolean		= LUA_TBOOLEAN,
+			light_data	= LUA_TLIGHTUSERDATA,
+			number		= LUA_TNUMBER,
+			string		= LUA_TSTRING,
+			table		= LUA_TTABLE,
+			function	= LUA_TFUNCTION,
+			data		= LUA_TUSERDATA,
+			thread		= LUA_TTHREAD
 		};
 
+		static std::string type_name(type type)
+		{
+			switch (type)
+			{
+				case none:	return "none";
+				case nil:	return "nil";
+				case boolean:	return "boolean";
+				case light_data:
+				case data:	return "userdata";
+				case number:	return "number";
+				case string:	return "string";
+				case table:	return "table";
+				case function:	return "function";
+				case thread:	return "thread";
+			}
+			return "?";
+		}
 
 		slot(const class script& s, int i = 0) :
 			index(i),
-			script_(const_cast<class script&>(s)) {}
-
-		/**
-		 * A copied value presently points to the same value, except the
-		 * real index is used.  That means that if a value that refers to a
-		 * frame referenced from the top of the stack will have its
-		 * normalized index copied into the new value object.
-		 */
-
-		//slot(const slot& copy) :
-			//index(copy.positiveIndex()),
-			//script_(copy.script_) {}
-
+			script_(const_cast<class script*>(&s)) {}
 
 		// check the type of the value
 		bool is_boolean() const
-		{ return (bool)lua_isboolean(script_.state_, index); }
+		{
+			return (bool)lua_isboolean(script_->state_, index);
+		}
 		bool is_imported_function() const
-		{ return (bool)lua_iscfunction(script_.state_, index); }
+		{
+			return (bool)lua_iscfunction(script_->state_, index);
+		}
 		bool is_function() const
-		{ return (bool)lua_isfunction(script_.state_, index); }
+		{
+			return (bool)lua_isfunction(script_->state_, index);
+		}
 		bool is_nil() const
-		{ return (bool)lua_isnil(script_.state_, index); }
+		{
+			return (bool)lua_isnil(script_->state_, index);
+		}
 		bool is_none() const
-		{ return (bool)lua_isnone(script_.state_, index); }
+		{
+			return (bool)lua_isnone(script_->state_, index);
+		}
 		bool is_none_or_nil() const
-		{ return (bool)lua_isnoneornil(script_.state_, index); }
+		{
+			return (bool)lua_isnoneornil(script_->state_, index);
+		}
 		bool is_number() const
-		{ return (bool)lua_isnumber(script_.state_, index); }
+		{
+			return (bool)lua_isnumber(script_->state_, index);
+		}
 		bool is_string() const
-		{ return (bool)lua_isstring(script_.state_, index); }
+		{
+			return (bool)lua_isstring(script_->state_, index);
+		}
 		bool is_table() const
-		{ return (bool)lua_istable(script_.state_, index); }
+		{
+			return (bool)lua_istable(script_->state_, index);
+		}
 		bool is_thread() const
-		{ return (bool)lua_isthread(script_.state_, index); }
+		{
+			return (bool)lua_isthread(script_->state_, index);
+		}
 		bool is_data() const
-		{ return (bool)lua_isuserdata(script_.state_, index); }
+		{
+			return (bool)lua_isuserdata(script_->state_, index);
+		}
 		bool is_light_data() const
-		{ return (bool)lua_islightuserdata(script_.state_, index); }
+		{
+			return (bool)lua_islightuserdata(script_->state_, index);
+		}
 
 		/**
 		 * Check the value and throw an error if its the wrong type.
-		 * There's a little caveat: This method never returns because it
-		 * does a long jump.  Consequently, constructed C++ objects which
-		 * exist on the stack between the current frame and some lua
-		 * function will not be destructed.  That's not a problem for
-		 * objects that only exist on the stack, but any objects that
-		 * allocate memory on the heap (such as containers or strings) will
-		 * leak.  Therefore, you should only call this method after
-		 * cleaning up such objects.  The best thing to do for defining
-		 * functions is to simply check all the parameters at the get-go
-		 * before any C++ objects are even constructed.
 		 */
-
-		void require_type(type t) const
+		const slot& require_type(type t) const
 		{
-			if (t != type())
-			{
-				luaL_typerror(script_.state_, index,
-							  lua_typename(script_.state_, t));
-			}
+			if (t != type()) raise_type_error(type_name(t));
+			return *this;
 		}
 
-		void raise(const char* error)
+		const slot&
+		require_boolean(const std::string& what = "boolean") const
 		{
-			luaL_argerror(script_.state_, index, error);
+			if (!is_boolean()) raise_type_error(what);
+			return *this;
 		}
-
-
-		slot& require_boolean()
+		const slot&
+		require_number(const std::string& what = "number") const
 		{
-			if (!is_boolean())
-			{
-				luaL_typerror(script_.state_, index, "boolean");
-			}
+			if (!is_number()) raise_type_error(what);
 			return *this;
 		}
-		slot& require_number()
+		const slot&
+		require_string(const std::string& what = "string") const
 		{
-			if (!is_number())
-			{
-				luaL_typerror(script_.state_, index, "number");
-			}
+			if (!is_string()) raise_type_error(what);
 			return *this;
 		}
-		slot& require_string()
+		const slot&
+		require_table(const std::string& what = "table") const
 		{
-			if (!is_string())
-			{
-				luaL_typerror(script_.state_, index, "string");
-			}
+			if (!is_table()) raise_type_error(what);
 			return *this;
 		}
-		slot& require_table()
+		const slot&
+		require_function(const std::string& what = "function") const
 		{
-			if (!is_table())
-			{
-				luaL_typerror(script_.state_, index, "table");
-			}
+			if (!is_function()) raise_type_error(what);
 			return *this;
 		}
-		slot& require_function()
+		const slot&
+		require_data(const std::string& what = "userdata") const
 		{
-			if (!is_function())
-			{
-				luaL_typerror(script_.state_, index, "function");
-			}
+			if (!is_data()) raise_type_error(what);
 			return *this;
 		}
-		slot& require_data()
+		const slot&
+		require_nil(const std::string& what = "nil") const
 		{
-			if (!is_data())
-			{
-				luaL_typerror(script_.state_, index, "data");
-			}
+			if (!is_nil()) raise_type_error(what);
 			return *this;
 		}
-		slot& require_nil()
+		const slot&
+		require_thread(const std::string& what = "thread") const
 		{
-			if (!is_nil())
-			{
-				luaL_typerror(script_.state_, index, "nil");
-			}
+			if (!is_thread()) raise_type_error(what);
 			return *this;
 		}
-		slot& require_thread()
+
+		template <class T>
+		const slot&
+		require_object(const std::string& what = typeid(T).name()) const
 		{
-			if (!is_thread())
+			if (!is_data()) raise_type_error(what);
+
+			slot metatable = push_metatable();
+			if (!metatable.is_table())
+			{
+				metatable.pop();
+				raise_type_error(what);
+			}
+
+			slot type = metatable.push_field("__cxxtype");
+			std::type_info* typeinfo;
+			if (!type.get(typeinfo))
 			{
-				luaL_typerror(script_.state_, index, "thread");
+				metatable.pop();
+				raise_type_error(what);
 			}
+
+			metatable.pop();
+			if (*typeinfo != typeid(T)) raise_type_error(what);
 			return *this;
 		}
 
-
 		/**
 		 * Get the type of the value.
 		 */
-
 		enum type type() const
 		{
-			return (enum type)lua_type(script_.state_, index);
+			return (enum type)lua_type(script_->state_, index);
 		}
 
 		/**
 		 * Get the name of the type of the value as a string.
 		 */
-
 		std::string type_name() const
 		{
-			return std::string(luaL_typename(script_.state_, index));
-		}
+			if (is_none())
+			{
+				return "none";
+			}
+			else if (is_data() && !is_light_data())
+			{
+				slot metatable = push_metatable();
+				if (!metatable.is_table())
+				{
+					metatable.pop();
+					return "userdata";
+				}
 
+				slot type = metatable.push_field("__cxxtype");
+				std::type_info* typeinfo;
+				if (!type.get(typeinfo))
+				{
+					metatable.pop();
+					return "userdata";
+				}
+
+				metatable.pop();
+				return typeinfo->name();
+			}
+			return luaL_typename(script_->state_, index);
+		}
 
 		/**
-		 * Get the length of the value according to the definition given by
-		 * Lua.
+		 * Get the length of the value according to the definition
+		 * given by Lua.
 		 */
-
+		size_t size() const
+		{
+			return lua_objlen(script_->state_, index);
+		}
 		size_t length() const
 		{
-			return lua_objlen(script_.state_, index);
+			return size();
 		}
 
-		int positiveIndex() const
+		int positive_index() const
 		{
-			if (index < 0) return index + lua_gettop(script_.state_) + 1;
-			else           return index;
+			if (index < 0)
+				return index + lua_gettop(script_->state_) + 1;
+			else
+				return index;
 		}
 
-
 		/**
 		 * Get a pointer value (for userdata, tables, threads, and
 		 * functions).
 		 */
-
 		const void* id() const
 		{
-			return lua_topointer(script_.state_, index);
+			return lua_topointer(script_->state_, index);
 		}
 
 		bool is_identical(const slot& rhs) const
 		{
-			return &script_ == &(rhs.script_) && index == rhs.index;
+			return script_ == rhs.script_ && index == rhs.index;
 		}
 
 		operator bool () const
@@ -293,44 +340,27 @@ public:
 			return !is_none();
 		}
 
-
 		bool operator == (const slot& rhs) const
 		{
-			return (bool)lua_equal(script_.state_, index, rhs.index);
-		}
-		bool operator != (const slot& rhs) const
-		{
-			return !(*this == rhs);
+			return (bool)lua_equal(script_->state_,
+					index, rhs.index);
 		}
 
 		bool operator < (const slot& rhs) const
 		{
-			return (bool)lua_lessthan(script_.state_, index, rhs.index);
-		}
-		bool operator <= (const slot& rhs) const
-		{
-			return *this < rhs || *this == rhs;
-		}
-		bool operator > (const slot& rhs) const
-		{
-			return !(*this <= rhs);
-		}
-		bool operator >= (const slot& rhs) const
-		{
-			return !(*this < rhs);
+			return (bool)lua_lessthan(script_->state_,
+					index, rhs.index);
 		}
 
-
 		/**
 		 * Convert the underlying value to a C++ type.
 		 */
-
 		template <class T>
 		bool get(T& value) const
 		{
 			if (is_number())
 			{
-				value = (T)lua_tointeger(script_.state_, index);
+				value = (T)lua_tointeger(script_->state_, index);
 				return true;
 			}
 			return false;
@@ -340,7 +370,7 @@ public:
 		{
 			if (is_number())
 			{
-				value = (float)lua_tonumber(script_.state_, index);
+				value = (float)lua_tonumber(script_->state_, index);
 				return true;
 			}
 			return false;
@@ -349,7 +379,7 @@ public:
 		{
 			if (is_number())
 			{
-				value = (double)lua_tonumber(script_.state_, index);
+				value = (double)lua_tonumber(script_->state_, index);
 				return true;
 			}
 			return false;
@@ -359,7 +389,7 @@ public:
 		{
 			if (is_boolean())
 			{
-				value = (bool)lua_toboolean(script_.state_, index);
+				value = (bool)lua_toboolean(script_->state_, index);
 				return true;
 			}
 			return false;
@@ -369,7 +399,7 @@ public:
 		{
 			if (is_string())
 			{
-				value = lua_tolstring(script_.state_, index, &size);
+				value = lua_tolstring(script_->state_, index, &size);
 				return true;
 			}
 			return false;
@@ -387,15 +417,20 @@ public:
 			return false;
 		}
 
-		bool get(void*& value) const
+		template <class T>
+		bool get(T*& value) const
 		{
 			if (is_data())
 			{
-				value = lua_touserdata(script_.state_, index);
+				value = reinterpret_cast<T*>(lua_touserdata(script_->state_, index));
 				return true;
 			}
 			return false;
 		}
+		void* get_data() const
+		{
+			return lua_touserdata(script_->state_, index);
+		}
 
 		template <class T>
 		bool get(std::vector<T>& array) const
@@ -404,19 +439,21 @@ public:
 
 			array.clear();
 
-			slot	value = script_[-1];
-			int		realIndex = positiveIndex();
+			slot	value = (*script_)[-1];
+			int	realIndex = positive_index();
 
 			bool done = false;
 			for (int i = 1; !done; ++i)
 			{
-				lua_rawgeti(script_.state_, realIndex, i);
+				lua_rawgeti(script_->state_, realIndex, i);
 
 				T v;
-				if (value.get(v)) array.push_back(v);
-				else              done = true;
+				if (value.get(v))
+					array.push_back(v);
+				else
+					done = true;
 
-				script_.pop();
+				script_->pop();
 			}
 
 			return true;
@@ -429,12 +466,12 @@ public:
 
 			dictionary.clear();
 
-			slot	key = script_[-2];
-			slot	value = script_[-1];
-			int		realIndex = positiveIndex();
+			slot	key = (*script_)[-2];
+			slot	value = (*script_)[-1];
+			int	realIndex = positive_index();
 
-			script_.push_nil();
-			while (lua_next(script_.state_, realIndex) != 0)
+			script_->push_nil();
+			while (lua_next(script_->state_, realIndex) != 0)
 			{
 				std::string k;
 				if (!key.is_number() && key.get(k))
@@ -442,9 +479,9 @@ public:
 					T v;
 					if (value.get(v)) dictionary[k] = v;
 				}
-				script_.pop();
+				script_->pop();
 			}
-			script_.pop();
+			script_->pop();
 
 			return true;
 		}
@@ -452,42 +489,55 @@ public:
 		/**
 		 * Get the value of a field from the table.
 		 */
-
 		template <class T, class V>
-		bool get(T& value, V field) const
+		bool get(T& value, const V& field) const
 		{
 			bool ret = push_field(field).get(value);
-			script_.pop();
+			script_->pop();
 			return ret;
 		}
 
-
 		template <class T, class V>
-		void set_field(T field, V value)
+		void set_field(const T& field, const V& value)
 		{
-			script_.push(field);
-			script_.push(value);
+			script_->push(field);
+			script_->push(value);
 			set_field();
 		}
 
 		void set_field()
 		{
-			lua_settable(script_.state_, index);
+			lua_settable(script_->state_, index);
 		}
 
+		void set_field(const std::string& field)
+		{
+			set_field(field.c_str());
+		}
+		void set_field(const char* field)
+		{
+			lua_setfield(script_->state_, index, field);
+		}
 
 		template <class T>
-		void set_field(const std::string& field, T value)
+		void set_field(const std::string& field, const T& value)
 		{
 			set_field(field.c_str(), value);
 		}
 		template <class T>
-		void set_field(const char* field, T value)
+		void set_field(const char* field, const T& value)
 		{
-			script_.push(value);
-			lua_setfield(script_.state_, index, field);
+			script_->push(value);
+			set_field(field);
 		}
 
+		/**
+		 * Set the top value to be the metatable of this value.
+		 */
+		void set_metatable()
+		{
+			lua_setmetatable(script_->state_, index);
+		}
 
 		/**
 		 * This set method, as opposed to the others, sets the value of the
@@ -496,80 +546,81 @@ public:
 		template <class T>
 		void set(T value)
 		{
-			script_.push(value);
-			replace();
-		}
-
-		void set()
-		{
-			replace();
+			script_->push(value);
+			set();
 		}
 
-
 		/**
 		 * Replace this value with the value at the top of the stack.
 		 */
+		void set()
+		{
+			lua_replace(script_->state_, index);
+		}
 
-		void replace()
+		void set_nil()
 		{
-			lua_replace(script_.state_, index);
+			script_->push_nil();
+			set();
 		}
 
 		void remove()
 		{
-			lua_remove(script_.state_, index);
+			lua_remove(script_->state_, index);
 		}
 
+		/**
+		 * Remove this value and everything above it.
+		 */
 		void pop()
 		{
-			// removes this slot, taking with it everything above it
-			script_.pop(script_.stack_size() - index + 1);
+			if
+				(index < 0) script_->pop(-index);
+			else
+				script_->pop(script_->stack_size() -
+						index + 1);
 		}
 
 		/**
 		 * Inserts the top-most value on the stack at position index,
 		 * shifting other values as needed.
 		 */
-
 		void insert_top_here()
 		{
-			lua_insert(script_.state_, index);
+			lua_insert(script_->state_, index);
 		}
 
-
 		/**
 		 * Copy the value and push the copy to the stack.
 		 */
-
 		slot push_copy() const
 		{
-			lua_pushvalue(script_.state_, index);
-			return script_.top();
+			lua_pushvalue(script_->state_, index);
+			return script_->top();
 		}
 		
 		slot push_metatable() const
 		{
-			lua_getmetatable(script_.state_, index);
-			return script_.top();
+			lua_getmetatable(script_->state_, index);
+			return script_->top();
 		}
 
 		slot push_environment() const
 		{
-			lua_getfenv(script_.state_, index);
-			return script_.top();
+			lua_getfenv(script_->state_, index);
+			return script_->top();
 		}
 
-
 		slot push_field() const
 		{
-			lua_gettable(script_.state_, index);
-			return script_.top();
+			lua_gettable(script_->state_, index);
+			return script_->top();
 		}
 
 		template <class T>
 		slot push_field(T index) const
 		{
-			script_.push(index);
+			script_->push(index);
 			return push_field();
 		}
 
@@ -579,28 +630,63 @@ public:
 		}
 		slot push_field(const char* name) const
 		{
-			lua_getfield(script_.state_, index, name);
-			return script_.top();
+			lua_getfield(script_->state_, index, name);
+			return script_->top();
 		}
 
-
 		class script& script()
 		{
-			return script_;
+			return *script_;
 		}
 
 		const class script& script() const
 		{
-			return script_;
+			return *script_;
 		}
 
+		/**
+		 * Throw an exception with a message formatted to communicate
+		 * a type mismatch with the argument represented by this slot.
+		 */
+		int raise_type_error(const std::string& expected) const
+		{
+			lua_Debug ar;
+			lua_getstack(script_->state_, 0, &ar);
+			lua_getinfo(script_->state_, "n", &ar);
+			const char* func = ar.name ? ar.name : "unknown function";
+
+			std::ostringstream stream;
+			stream << "bad argument " << index << " to '" << func
+				   << "' (" << expected << " expected, got "
+				   << type_name() << ")";
+
+			throw std::invalid_argument(stream.str());
+			return 0;
+		}
+
+		/**
+		 * Throw a generic error concerning this particular slot.
+		 */
+		int raise(const std::string& message) const
+		{
+			lua_Debug ar;
+			lua_getstack(script_->state_, 0, &ar);
+			lua_getinfo(script_->state_, "n", &ar);
+			const char* func = ar.name ? ar.name : "unknown function";
+
+			std::ostringstream stream;
+			stream << "bad argument " << index << " to '" << func
+				   << "' (" << message << ")";
+
+			throw std::invalid_argument(stream.str());
+			return 0;
+		}
 
 	private:
 
-		class script& script_;
+		mutable class script* script_;
 	};
 
-
 	script() :
 		state_(0)
 	{
@@ -612,7 +698,6 @@ public:
 		destroy();
 	}
 
-
 	static script_ptr alloc()
 	{
 		return script_ptr(new script);
@@ -622,73 +707,90 @@ public:
 	{
 		if (state_) destroy();
 		state_ = luaL_newstate();
-		registry().set_field("Script_hh_Object", (void*)this);
 	}
 
-
 	void import_standard_libraries()
 	{
 		luaL_openlibs(state_);
 	}
 
+	void import_safe_standard_libraries()
+	{
+		import_base_library();
+		import_string_library();
+		import_table_library();
+		import_math_library();
+		import_os_library();
+		import_debug_library();
+
+		slot g = globals();
+
+		push_nil(); g.set_field("dofile");
+		push_nil(); g.set_field("loadfile");
+		push_nil(); g.set_field("require");
+		push_nil(); g.set_field("io");
+		push_nil(); g.set_field("package");
+		slot os = g.push_field("os");
+		push_nil(); os.set_field("execute");
+		push_nil(); os.set_field("exit");
+		push_nil(); os.set_field("getenv");
+		push_nil(); os.set_field("remove");
+		push_nil(); os.set_field("rename");
+		push_nil(); os.set_field("tmpname");
+		pop();
+	}
+
 	void import_base_library()
 	{
-		lua_pushcfunction(state_, luaopen_base);
+		push(luaopen_base);
 		push(LUA_COLIBNAME);
 		call(1, 0);
 	}
-
 	void import_package_library()
 	{
-		lua_pushcfunction(state_, luaopen_package);
+		push(luaopen_package);
 		push(LUA_LOADLIBNAME);
 		call(1, 0);
 	}
-
 	void import_string_library()
 	{
-		lua_pushcfunction(state_, luaopen_string);
+		push(luaopen_string);
 		push(LUA_STRLIBNAME);
 		call(1, 0);
 	}
-
 	void import_table_library()
 	{
-		lua_pushcfunction(state_, luaopen_table);
+		push(luaopen_table);
 		push(LUA_TABLIBNAME);
 		call(1, 0);
 	}
-
 	void import_math_library()
 	{
-		lua_pushcfunction(state_, luaopen_math);
+		push(luaopen_math);
 		push(LUA_MATHLIBNAME);
 		call(1, 0);
 	}
-
 	void import_io_library()
 	{
-		lua_pushcfunction(state_, luaopen_io);
+		push(luaopen_io);
 		push(LUA_IOLIBNAME);
 		call(1, 0);
 	}
-
 	void import_os_library()
 	{
-		lua_pushcfunction(state_, luaopen_os);
+		push(luaopen_os);
 		push(LUA_OSLIBNAME);
 		call(1, 0);
 	}
-
 	void import_debug_library()
 	{
-		lua_pushcfunction(state_, luaopen_debug);
+		push(luaopen_debug);
 		push(LUA_DBLIBNAME);
 		call(1, 0);
 	}
 
-
-	void import_function(const std::string& name, const function& function)
+	void
+	import_function(const std::string& name, const function& function)
 	{
 		push(function);
 		lua_setglobal(state_, name.c_str());
@@ -704,8 +806,7 @@ public:
 		return status(luaL_dofile(state_, file.c_str()));
 	}
 
-
-	/**
+	/*
 	 * Thread-handling methods.
 	 */
 
@@ -714,9 +815,10 @@ public:
 		return script(state_);
 	}
 
-	void push_thread()
+	slot push_thread()
 	{
 		lua_pushthread(state_);
+		return top();
 	}
 
 	status resume(int nargs)
@@ -724,7 +826,7 @@ public:
 		return status(lua_resume(state_, nargs));
 	}
 
-	status getStatus() const
+	status thread_status() const
 	{
 		return status(lua_status(state_));
 	}
@@ -736,28 +838,34 @@ public:
 
 	bool is_main_thread() const
 	{
-		return is_main_thread_;
+		bool is_main = lua_pushthread(state_);
+		lua_pop(state_, 1);
+		return is_main;
 	}
 
-
 	/**
-	 * Throw an error with the value at the top of the stack.  This method
-	 * never returns because it does a long jump.  Consequently,
-	 * constructed C++ objects  which exist on the stack between the
-	 * current frame and some lua function will not be destructed.  That's
-	 * not a problem for objects that only exist on the stack, but any
-	 * objects that allocate memory on the heap (such as containers or
-	 * strings) will leak.  Therefore, you should only call this method
-	 * after cleaning up such objects.
+	 * Throw an error with the value at the top of the stack.  If this is
+	 * called from an imported function, the error will be caught and
+	 * returned on the stack when the execution aborts.
 	 */
-
-	void raise()
+	int raise()
 	{
-		lua_error(state_);
+		throw std::runtime_error("");
+		return 0;
 	}
 
-
 	/**
+	 * Throw an error with a given message describing the problem.  If this
+	 * is called from an imported function, the error will be caught and
+	 * returned on the stack when the execution aborts.
+	 */
+	int raise(const std::string& message)
+	{
+		throw std::runtime_error(message);
+		return 0;
+	}
+
+	/*
 	 * Get significant values.
 	 */
 
@@ -765,23 +873,19 @@ public:
 	{
 		return slot(*this, globals_index);
 	}
-
 	slot registry() const
 	{
 		return slot(*this, registry_index);
 	}
-
 	slot environment() const
 	{
 		return slot(*this, environment_index);
 	}
-
 	slot top() const
 	{
 		return slot(*this, stack_size());
 	}
 
-
 	/**
 	 * Set the size of the stack.
 	 * \param size The stack size.
@@ -809,7 +913,6 @@ public:
 		stack_size(0);
 	}
 
-
 	/**
 	 * Makes sure there is at least extra more places on the stack.
 	 * Returns false if space couldn't be created.  Just like with the
@@ -817,12 +920,11 @@ public:
 	 * enough to hold whatever you want to push on it.  This is usually
 	 * only an issue if you're pushing stuff in a loop.
 	 */
-	bool checkStack(int extra)
+	bool check_stack(int extra)
 	{
 		return (bool)lua_checkstack(state_, extra);
 	}
 
-
 	/**
 	 * Concatenates the top-most n slots on the stack.
 	 */
@@ -831,12 +933,56 @@ public:
 		lua_concat(state_, n);
 	}
 
-
-	/**
+	/*
 	 * Push some values onto the stack.
 	 */
-	template <class T>
-	slot push(T value)
+
+	slot push(char value)
+	{
+		lua_pushinteger(state_, lua_Integer(value));
+		return top();
+	}
+	slot push(unsigned char value)
+	{
+		lua_pushinteger(state_, lua_Integer(value));
+		return top();
+	}
+	slot push(short value)
+	{
+		lua_pushinteger(state_, lua_Integer(value));
+		return top();
+	}
+	slot push(unsigned short value)
+	{
+		lua_pushinteger(state_, lua_Integer(value));
+		return top();
+	}
+	slot push(int value)
+	{
+		lua_pushinteger(state_, lua_Integer(value));
+		return top();
+	}
+	slot push(unsigned int value)
+	{
+		lua_pushinteger(state_, lua_Integer(value));
+		return top();
+	}
+	slot push(long value)
+	{
+		lua_pushinteger(state_, lua_Integer(value));
+		return top();
+	}
+	slot push(unsigned long value)
+	{
+		lua_pushinteger(state_, lua_Integer(value));
+		return top();
+	}
+	slot push(long long value)
+	{
+		lua_pushinteger(state_, lua_Integer(value));
+		return top();
+	}
+	slot push(unsigned long long value)
 	{
 		lua_pushinteger(state_, lua_Integer(value));
 		return top();
@@ -850,12 +996,12 @@ public:
 
 	slot push(float value)
 	{
-		lua_pushnumber(state_, (lua_Number)value);
+		lua_pushnumber(state_, lua_Number(value));
 		return top();
 	}
 	slot push(double value)
 	{
-		lua_pushnumber(state_, (lua_Number)value);
+		lua_pushnumber(state_, lua_Number(value));
 		return top();
 	}
 
@@ -877,18 +1023,56 @@ public:
 
 	slot push(const function& function)
 	{
-		functions_.push_back(function);
-		lua_pushlightuserdata(state_, (void*)&functions_.back());
-		lua_pushcclosure(state_, dispatch_call, 1);
+		push<script::function>(function);
+		push_pointer(this);
+		push(call_functor, 2);
 		return top();
 	}
-
-	slot push(void* data)
+	slot push(cfunction function)
 	{
-		lua_pushlightuserdata(state_, data);
+		push_pointer(function);
+		push_pointer(this);
+		push(call_function, 2);
 		return top();
 	}
 
+	template <class T>
+	slot push(const T& object)
+	{
+		void* storage;
+		slot copy = push_data(storage, sizeof(T));
+		new(storage) T(object);
+
+		push_class_metatable<T>();
+		copy.set_metatable();
+		return copy;
+	}
+
+	template <class T>
+	slot push_class(const function& ctor)
+	{
+		slot metatable = push_class_metatable<T>();
+
+		slot constructor = push_table();
+		push(ctor);
+		constructor.set_field("__call");
+		metatable.set_metatable();
+
+		return metatable;
+	}
+	template <class T>
+	slot push_class(cfunction ctor)
+	{
+		slot metatable = push_class_metatable<T>();
+
+		slot constructor = push_table();
+		push(ctor);
+		constructor.set_field("__call");
+		metatable.set_metatable();
+
+		return metatable;
+	}
+
 	slot push_nil()
 	{
 		lua_pushnil(state_);
@@ -908,27 +1092,66 @@ public:
 	}
 
 	slot push_code(const std::string& name,
-				   const char* buffer,
-				   size_t size,
-				   status& result)
+			const char* buffer, size_t size, status& result)
 	{
 		result = status(luaL_loadbuffer(state_,
-										buffer, size, name.c_str()));
+					buffer, size, name.c_str()));
 		return top();
 	}
 
-	slot push_new_data(void*& data, size_t size)
+	slot push_data(void*& data, size_t size)
 	{
 		data = lua_newuserdata(state_, size);
 		return top();
 	}
 
-	slot push_new_table(int narr = 0, int nrec = 0)
+	template <class T>
+	slot push_pointer(const T* ptr)
+	{
+		lua_pushlightuserdata(state_,
+				const_cast<void*>((const void*)ptr));
+		return top();
+	}
+	slot push_pointer(cfunction function)
+	{
+		return push_pointer((void*)function);
+	}
+
+	slot push_table(const std::string& name, int narr = 0, int nrec = 0)
+	{
+		if (name.empty()) return globals().push_field("_G");
+
+		slot table = globals().push_field(name);
+		if (table.is_table()) return table;
+
+		pop();
+		push_table(narr, nrec);
+		globals().set_field(name);
+
+		return globals().push_field(name);
+	}
+	slot push_table(int narr = 0, int nrec = 0)
 	{
 		lua_createtable(state_, narr, nrec);
 		return top();
 	}
 
+	slot push_metatable(const std::string& type, bool& is_new)
+	{
+		is_new = luaL_newmetatable(state_, type.c_str());
+		return top();
+	}
+	slot push_metatable(const std::string& type)
+	{
+		luaL_newmetatable(state_, type.c_str());
+		return top();
+	}
+
+	template <class T>
+	slot push_type()
+	{
+		return push_pointer(&typeid(T));
+	}
 
 	/**
 	 * Call a function on the stack.  The correct procedure is to push a
@@ -936,101 +1159,194 @@ public:
 	 * will pop them off upon return, leaving up to nresults return values
 	 * (default is any number of return values, depending on the callee).
 	 */
-
 	status call(int nargs = 0, int nresults = LUA_MULTRET)
 	{
 		return status(lua_pcall(state_, nargs, nresults, 0));
 	}
 
-
 	/**
 	 * Pops n values from the top of the stack.
 	 */
-
 	void pop(int n = 1)
 	{
 		lua_pop(state_, n);
 	}
 
-
 	/**
 	 * Index into the stack to get a slot.
 	 */
-
 	slot operator [] (int index) const
 	{
 		return slot(*this, index);
 	}
 
-
-	/**
+	/*
 	 * Control over the garbage collection process.
 	 */
 
-	void collect_all()
+	void collect_garbage()
 	{
 		lua_gc(state_, LUA_GCCOLLECT, 0);
 	}
+	void collect_garbage(int step)
+	{
+		lua_gc(state_, LUA_GCSTEP, step);
+	}
 
-	void stop_collector()
+	void disable_garbage_collector()
 	{
 		lua_gc(state_, LUA_GCSTOP, 0);
 	}
-
-	void restart_collector()
+	void enable_garbage_collector()
 	{
 		lua_gc(state_, LUA_GCRESTART, 0);
 	}
 
-	int memory_used() const
+	float memory_used() const
 	{
 		// in kilobytes
-		return lua_gc(state_, LUA_GCCOUNT, 0);
-	}
-
-	void collect(int step)
-	{
-		lua_gc(state_, LUA_GCSTEP, step);
+		return lua_gc(state_, LUA_GCCOUNT, 0) +
+			   lua_gc(state_, LUA_GCCOUNTB, 0) / 1024.0f;
 	}
 
-	void tune_collector(int pause, int step)
+	void tune_garbage_collector(int pause, int step = 200)
 	{
 		lua_gc(state_, LUA_GCSETPAUSE, pause);
 		lua_gc(state_, LUA_GCSETSTEPMUL, step);
 	}
 
-
 private:
 
 	script(lua_State* state) :
-		state_(lua_newthread(state)),
-		is_main_thread_(false) {}
+		state_(lua_newthread(state)) {}
 
-	static int dispatch_call(lua_State* state)
+	slot push(lua_CFunction function, int upvalues = 0)
 	{
-		const function* function = (const script::function*)lua_touserdata(state,
+		lua_pushcclosure(state_, function, upvalues);
+		return top();
+	}
+
+	template <class T>
+	slot push_class_metatable()
+	{
+		bool is_new;
+		slot metatable = push_metatable(typeid(T).name(), is_new);
+		if (is_new)
+		{
+			metatable.push_copy();			// class behavior
+			metatable.set_field("__index");
+			push_type<T>();
+			metatable.set_field("__cxxtype");	// type_info
+			push(object_finalizer_<T>);
+			metatable.set_field("__gc");		// finalizer
+			//push(object_tostring_<T>);
+			//metatable.set_field("__tostring");	// tostring
+		}
+		return metatable;
+	}
+
+	template <class T>
+	static int object_tostring_(lua_State* state)
+	{
+		std::ostringstream stream;
+		stream << *reinterpret_cast<T*>(lua_touserdata(state, 1));
+		lua_pushlstring(state,
+				stream.str().c_str(), stream.str().length());
+		return 1;
+	}
+
+	template <class T>
+	static int object_finalizer_(lua_State* state)
+	{
+		reinterpret_cast<T*>(lua_touserdata(state, 1))->~T();
+		return 0;
+	}
+
+	static int call_functor(lua_State* state)
+	{
+		function* function = (script::function*)lua_touserdata(state,
+				lua_upvalueindex(1));
+
+		script* script = (moof::script*)lua_touserdata(state,
+				lua_upvalueindex(2));
+
+		try
+		{
+			return (*function)(*script);
+		}
+		catch (const std::exception& e)
+		{
+			if (0 < std::strlen(e.what()))
+			{
+				luaL_where(state, 1);
+				lua_pushstring(state, e.what());
+				lua_concat(state, 2);
+			}
+			return lua_error(state);
+		}
+		catch (const char* e)
+		{
+			luaL_where(state, 1);
+			lua_pushstring(state, e);
+			lua_concat(state, 2);
+			return lua_error(state);
+		}
+		catch (...)
+		{
+			return lua_error(state);
+		}
+	}
+
+	static int call_function(lua_State* state)
+	{
+		cfunction function = (cfunction)lua_touserdata(state,
 				lua_upvalueindex(1));
 
-		lua_getfield(state, LUA_REGISTRYINDEX, "Script_hh_Object");
-		script* script = (moof::script*)lua_touserdata(state, -1);
-		lua_pop(state, 1);
+		script* script = (moof::script*)lua_touserdata(state,
+				lua_upvalueindex(2));
 
-		return (*function)(*script);
+		try
+		{
+			return function(*script);
+		}
+		catch (const std::exception& e)
+		{
+			if (0 < std::strlen(e.what()))
+			{
+				luaL_where(state, 1);
+				lua_pushstring(state, e.what());
+				lua_concat(state, 2);
+			}
+			return lua_error(state);
+		}
+		catch (const char* e)
+		{
+			luaL_where(state, 1);
+			lua_pushstring(state, e);
+			lua_concat(state, 2);
+			return lua_error(state);
+		}
+		catch (...)
+		{
+			return lua_error(state);
+		}
 	}
 
 	void destroy()
 	{
-		if (is_main_thread_) lua_close(state_);
+		if (is_main_thread()) lua_close(state_);
 	}
 
 	lua_State*			state_;
-	bool				is_main_thread_;
-	std::list<function>	functions_;
 };
 
+using namespace std::rel_ops;
 
-inline std::ostream& operator << (std::ostream& stream,
-								  const script::slot& slot)
+/**
+ * Output a script value to a stream.
+ */
+inline std::ostream&
+operator << (std::ostream& stream, const script::slot& slot)
 {
 	std::string	str;
 	bool		boolean;
@@ -1042,7 +1358,7 @@ inline std::ostream& operator << (std::ostream& stream,
 	else if (slot.get(boolean))
 	{
 		if (boolean) stream << "true";
-		else         stream << "false";
+		else stream << "false";
 	}
 	else if (slot.is_nil())
 	{