It seems to use a '+' instead of ','.
On Sat, 1 Feb 2014, Benjamin Striegel wrote:
How about supporting type aliases as Scala does?
In theory I think that should be achievable today, using trait inheritance:
trait MyT : Clone, Eq {}
...at least, I *think* we allow multiple trait inheritance. Not sure what
the syntax is!
On Sat, Feb 1, 2014 at 6:12 PM, Vladimir Lushnikov <
[email protected]> wrote:
Placing type bounds before the name of the thing you are trying to declare
feels unnatural to me. And the generic block is far too much boilerplate!
How about supporting type aliases as Scala does? So you write:
type MyT = Clone + Eq
fn foo<MyT, U>(t: T, u: U) -> ...
and the 'type' is just an alias for any type that has Clone + Eq?
Obviously the above only solves repeating yourself for complex type
constraints.
Also, reusing 'for' would be confusing as well, because you expect a loop
there, not a generic type bound. How about 'any':
any <T: Clone + Eq, U> fn foo (t: T, u: U) -> ...
?
On Sat, Feb 1, 2014 at 11:06 PM, Benjamin Striegel <[email protected]
wrote:
Another point in favor of this plan is that it would eliminate the need
to put type parameters directly after the `impl`, which to be honest *is*
pretty weird and inconsistent with the rest of the language. But I'm still
not sure how I feel about the look of it:
for <T: Clone+Eq, U> fn foo(t: T, u: U) -> (T, U) {
If you choose *not* to wrap after the type parameters there, you're
really obscuring what the heck you're trying to declare.
Heck, maybe what we're really asking for is for the ability to have
"generic blocks" within which type parameters can be declared once:
for <T: Clone+Eq, U> {
fn foo(t: T, u: U) -> (T, U) {
...but that's even *more* boilerplate!
On Sat, Feb 1, 2014 at 5:59 PM, Benjamin Striegel <[email protected]
wrote:
Yes, and I don't have a solution for that.
Well, it's not like we don't already stumble here a bit, what with
requiring ::<> instead of just <>. Not sure how much other people value the
consistency here.
On Sat, Feb 1, 2014 at 5:58 PM, Corey Richardson <[email protected]>wrote:
On Sat, Feb 1, 2014 at 5:55 PM, Benjamin Striegel
<[email protected]> wrote:
First of all, why a new keyword? Reusing `for` here would be totally
unambiguous. :P And also save us from creating the precedent of
multi-word
keywords.
I'd be equally happy with for instead of forall.
Secondly, currently Rust has a philosophy of use-follows-declaration
(i.e.
the syntax for using something mirrors the syntax for declaring it).
This
would eliminate that.
Yes, and I don't have a solution for that.
_______________________________________________
Rust-dev mailing list
[email protected]
https://mail.mozilla.org/listinfo/rust-dev
--
Scott Lawrence
_______________________________________________
Rust-dev mailing list
[email protected]
https://mail.mozilla.org/listinfo/rust-dev
