[mercury-users] Abstraction barrier

Michael Day mikeday at yeslogic.com
Tue May 13 16:49:13 AEST 2003

> > Perhaps this way, and only provide accessor functions for magic_data that
> > require a magic_token to operate, such that even if the function returns
> > magic_data nothing can be done with it later?

I thought of another possibility:

:- pred foo(magic_data, T, T).
:- mode foo(ui, in, out) is det.

If magic_data must stay unique, then it can only be manipulated with
accessor functions that preserve its uniqueness and cannot be returned or
aliased. Sounds about right, but I expect the limitations of the 
compiler's support for ui modes will be its undoing.


YesLogic Prince prints XML!

mercury-users mailing list
post:  mercury-users at cs.mu.oz.au
administrative address: owner-mercury-users at cs.mu.oz.au
unsubscribe: Address: mercury-users-request at cs.mu.oz.au Message: unsubscribe
subscribe:   Address: mercury-users-request at cs.mu.oz.au Message: subscribe

More information about the users mailing list