On Thursday, 23 August 2018 at 23:36:07 UTC, Chris M. wrote:
Heck, now that I'm looking at it, DIP25 seems like a more
restricted form of Rust's lifetimes. Let me know if I'm just
completely wrong about this, but
I think DIP 25 is analogous to Problem #3 for Rust's Non-Lexical
Lifetimes:
http://smallcultfollowing.com/babysteps/blog/2016/04/27/non-lexical-lifetimes-introduction/#problem-case-3-conditional-control-flow-across-functions
http://smallcultfollowing.com/babysteps/blog/2016/05/09/non-lexical-lifetimes-adding-the-outlives-relation/#problem-case-3-revisited
would basically be like (pseudosyntax)
@safe ref'a int identity(ref'a int x) {
return x; // fine
}
Maybe the more sane thing would be a syntax that visually ties
them together as above. Obviously we're looking at possibly
breaking changes, but how widespread would they be?
void betty(ref'a scope int* r, scope'a int* p); // syntax is
not so nice since I just arbitrarily stuck them on different
keywords, but that's besides the point here
I wish I had been more involved in D when DIP 25 and DIP 1000
were being proposed, as I don't think the designs were thoroughly
vetted. It's taken me at least a year to even begin getting a
grasp on it.
I think DIP 25 and DIP 1000 should have been combined and thought
of holistically as simply "annotated lifetimes in D" rather than
separate things. I think then it becomes easier to visualize
what the problem is and see, potentially many, alternatives.
Given the investments that have already been made in DIP 25 and
DIP 1000, it's going to take an extremely motivated individual to
fight an uphill battle to change direction now, I'm afraid. If
working on D was my full-time job, I'd do it, but who in this
community has such resources.
Mike
