RealWorld -is:package -package:midi

RealWorld is deeply magical. It is primitive, but it is not unlifted (hence ptrArg). We never manipulate values of type RealWorld; it's only used in the type system, to parameterise State#.
RealWorld is deeply magical. It is primitive, but it is not unlifted (hence ptrArg). We never manipulate values of type RealWorld; it's only used in the type system, to parameterise State#.
The s type for running OW in IO.
The token used in the implementation of the IO monad as a state monad. It does not pass any information at runtime. See also runRW#.