On Mon, Sep 15, 2008 at 10:09:41PM -0500, John M. Dlugosz wrote: > Darren Duncan darren-at-darrenduncan.net |Perl 6| wrote: >>> So, how does one get an object to pretend to be a value type for >>> purposes of assignment? >> >> I have been under the impression that value types are supposed to >> define immutable objects, or at least objects that pretend to be >> immutable; any operators on them would produce new objects rather than >> mutating existing ones. >> [...] > > I agree. A "value type" is "immutable", where the identity is keyed to > the value. Making a "value type" that can mutate can cause confusion. > > I'm now thinking that the normal = you write should always give > reference assignment semantics. In the case of "value types", assuming > they are indeed immutable, it does not matter whether they have value or > reference assignment semantics, since the same value will give the same > identity, regardless of memory (or in-register) representation. > [...]
I think I can accept this reasoning for now, although it has some strong implications for managing array elements and binding operations (especially given Parrot's model of them). But we'll come up with something, and thanks. Pm
