[mercury-users] Modular data-abstraction and mostly unique modes.

[Henk Vandecasteele]

Fergus Henderson wrote:
> 
> On 07-Jan-1998, Henk Vandecasteele <Henk.Vandecasteele at cs.kuleuven.ac.be> wrote:
> > Anyway, maybe I'm missing some points, but I find the mode-system
> > when doing more complicated things like above difficult to use.
> > I for instance believe that instantiation information and uniqueness
> > information is something different. And glueing them together makes
> > things unclear.
> 
> Well, instantiation information and uniqueness are different, but they
> are very closely linked -- so closely as to be pretty much
> inextricable, I think.  For example, if a variable is not uniquely
> referenced, then you cannot be sure that it is free -- because it may
> have been bound via one of the other references.

One improvement could be to make uniqueness-information a syntactical
annotation to the instantation-information.

Henk