On Monday, 15 December 2014 at 11:32:11 UTC, Dicebot wrote:
On Monday, 15 December 2014 at 11:23:28 UTC, Marc Schütz wrote:
I think there are two cases that are relevant. 1) the tree
nodes don't own their children, instead they are managed by -
let's say - a region allocator, and 2) the tree nodes do own
their children. In both cases, they can declare the children
as scope members (assuming a proposal that allows that).
The only case I can think of where the children should not be
scope members is when they are GC managed. But in this case,
you don't need to worry about references to them escaping.
Therefore, I don't see a use case for transitivity of scope,
from a conceptional point of view. If a particular design
makes transitivity necessary, this points to a flaw in the
design, IMO.
Actually I think in neither case children should be declared as
scope members. Instead those should be declared as private
members but methods that return pointers/references to children
would be declared to return (transitive) scope
pointers/references.
I see this as the same thing, conceptually (module the
"transitive" in in your parentheses). It's just a different
mechanism. Scope members are just a short-cut instead of writing
an accessor method that returns scope.
For me "scopeness" is a property of "view", not object itself -
this also makes ownership method of actual data irrelevant.
Yes, and this would be true for scope members just the same. (If
the aggregate "owns" it's scope members, it will however get in
trouble when it tries to free() them, therefore your mechanism is
more appropriate in this case.)
Only difference between GC owned data and stack allocated one
is that former can have scoped view optionally but for the
latter compiler must force it as the only available.
Agreed.
