allow LuaManager::RunExpression to return a function

show the filename when a full script has an error
use LuaManager::RunExpression in LuaExpression

stepmania/src/ActorCommands.cpp

@@ -71,7 +71,7 @@ void ActorCommands::Register()
 
 
 	CString s2 = s.str();
-	LUA->RunScript( s2, 1 );
+	LUA->RunScript( s2, "in", 1 );
 
 	/* The function is now on the stack. */
 	this->SetFromStack();

stepmania/src/LuaManager.cpp

@@ -261,16 +261,16 @@ bool LuaManager::RunScriptFile( const CString &sFile )
 		return false;
 	}
 
-	return RunScript( sScript );
+	return RunScript( sScript, sFile );
 }
 
-bool LuaManager::RunScript( const CString &sScript, int iReturnValues )
+bool LuaManager::RunScript( const CString &sScript, const CString &sName, int iReturnValues )
 {
 	// load string
 	{
 		ChunkReaderData data;
 		data.buf = &sScript;
-		int ret = lua_load( L, ChunkReaderString, &data, "in" );
+		int ret = lua_load( L, ChunkReaderString, &data, sName );
 
 		if( ret )
 		{
@@ -303,16 +303,9 @@ bool LuaManager::RunScript( const CString &sScript, int iReturnValues )
 
 bool LuaManager::RunExpression( const CString &sExpression )
 {
-	if( !RunScript( "return " + sExpression, 1 ) )
+	if( !RunScript( "return " + sExpression, "in", 1 ) )
 		return false;
 
-	ASSERT_M( lua_gettop(L) == 1, ssprintf("%i", lua_gettop(L)) );
-
-	/* Don't accept a function as a return value; if you really want to use a function
-	 * as a boolean, convert it before returning. */
-	if( lua_isfunction( L, -1 ) )
-		RageException::Throw( "result is a function; did you forget \"()\"?" );
-
 	return true;
 }
 
@@ -321,6 +314,10 @@ bool LuaManager::RunExpressionB( const CString &str )
 	if( !RunExpression( str ) )
 		return false;
 
+	/* Don't accept a function as a return value. */
+	if( lua_isfunction( L, -1 ) )
+		RageException::Throw( "result is a function; did you forget \"()\"?" );
+
 	bool result = !!lua_toboolean( L, -1 );
 	lua_pop( L, -1 );
 
@@ -332,6 +329,10 @@ float LuaManager::RunExpressionF( const CString &str )
 	if( !RunExpression( str ) )
 		return 0;
 
+	/* Don't accept a function as a return value. */
+	if( lua_isfunction( L, -1 ) )
+		RageException::Throw( "result is a function; did you forget \"()\"?" );
+
 	float result = (float) lua_tonumber( L, -1 );
 	lua_pop( L, -1 );
 
@@ -343,7 +344,9 @@ bool LuaManager::RunExpressionS( const CString &str, CString &sOut )
 	if( !RunExpression( str ) )
 		return false;
 
-	ASSERT( lua_gettop(L) > 0 );
+	/* Don't accept a function as a return value. */
+	if( lua_isfunction( L, -1 ) )
+		RageException::Throw( "result is a function; did you forget \"()\"?" );
 
 	sOut = lua_tostring( L, -1 );
 	lua_pop( L, -1 );

stepmania/src/LuaManager.h

@@ -22,7 +22,7 @@ public:
 	void ResetState();
 
 	/* Run a complete script in the global environment, which returns no value. */
-	bool RunScript( const CString &sScript, int iReturnValues = 0 );
+	bool RunScript( const CString &sScript, const CString &sName, int iReturnValues = 0 );
 
 	/* Run an expression in the global environment, returning the given type. */
 	bool RunExpressionB( const CString &str );

stepmania/src/LuaReference.cpp

@@ -114,7 +114,7 @@ void LuaExpression::SetFromExpression( const CString &sExpression )
 
 void LuaExpression::Register()
 {
-	LUA->RunScript( "return " + m_sExpression, 1 );
+	LUA->RunExpression( m_sExpression );
 
 	/* Store the result. */
 	this->SetFromStack();