A method for resolving a type in a programming language to a resolve stage is provided. The method includes determining whether a version at the resolve stage of the type exists. The method further includes, if the version at the resolve stage does not exist, allowing a thread exclusive access to the type, resolving the type from an original resolve stage to the resolve stage, by the thread, by adding resolution information for the resolve stage to the type, and creating the version of the type based on the resolving by creating a copy of the type, where the copy of the type is at the resolve stage. Two or more versions are associated with the type, and the two or more versions are at different resolve stages.