LuaHelpers::RunExpression

stepmania/src/LuaManager.cpp

@@ -539,6 +539,17 @@ bool LuaHelpers::RunScript( Lua *L, const RString &sExpression, const RString &s
 	return true;
 }
 
+bool LuaHelpers::RunExpression( Lua *L, const RString &sExpression )
+{
+	RString sFullExpression = "return " + sExpression;
+
+	bool bSuccess = LuaHelpers::RunScript( L, sFullExpression, "", 1 );
+	if( !bSuccess )
+		lua_pushnil( L );
+
+	return bSuccess;
+}
+
 bool LuaHelpers::RunExpressionB( const RString &str )
 {
 	Lua *L = LUA->Get();

stepmania/src/LuaManager.h

@@ -56,6 +56,10 @@ namespace LuaHelpers
 	 * The return value is left on the Lua stack. */
 	bool RunScript( Lua *L, const RString &sExpression, const RString &sName = "", int iReturnValues = 0 );
 
+	/* Run the given expression, returning a single value, and leave the return value on the
+	 * stack.  On error, push nil. */
+	bool RunExpression( Lua *L, const RString &sExpression );
+
 	bool RunScriptFile( const RString &sFile );
 
 	/* Strip "//" comments and "+". */