> Using Rusts' retarded enum keyword for your example doesn't exactly make your point understandable, especially when talking in the context of actual enumerati

> Using Rusts' retarded enum keyword for your example doesn't exactly make your point understandable, especially when talking in the context of actual enumerations. data Event = System SystemEvent | User a > Anyway, the point of what gp describes is to do this in a single integer without overhead so a naive sum type is not the solution. Virtually all event systems end up carrying auxilary event data of some form, so sum types are what you want regardless.