I was wondering if we have considered adding support for providing Xcode automatic fix-it’s for closures being returned from a function.
For example, here is an incorrect version of a function that requires two `@escaping` keywords to be inserted.
func mapping <A, B, C> (f: (A) -> (B)) -> ((C, B) -> (C)) -> ((C, A) -> (C))
Despite the complexity, the compiler manages to catch two errors.
1. Closure use of non-escaping parameter `f` may allow it to escape
a. Automatic Fix-it by doing `f: @escaping (A) - > (B)`
2. Closure use of non-escaping parameter `reducer` may allow it to escape
b. No Fix-it provided <————
As you see above, the two places where a compile-time error occurred had the same exact problem; they both needed a `@escaping`. However, while the function parameter was offered an automatic fix-it, the nested closure being returned was not.
Here’s the correct version of the function.
func mapping <A, B, C> (f: @escaping (A) -> (B)) -> (@escaping ((C, B) -> (C))) -> ((C, A) -> (C)) {
return { reducer in
return { accum, input in
reducer(accum, f(input))
}
}
}
I know this is a small feature for a very specific use case but I think it could help make Xcode a little smarter :D
Thanks for reading!
You should probably file a Radar for this, since Xcode isn’t part of the Swift project.
Saagar Jha
···
On Jul 13, 2017, at 19:46, iCloud via swift-evolution <swift-evolution@swift.org> wrote:
Hi Swift community,
I was wondering if we have considered adding support for providing Xcode automatic fix-it’s for closures being returned from a function.
For example, here is an incorrect version of a function that requires two `@escaping` keywords to be inserted.
func mapping <A, B, C> (f: (A) -> (B)) -> ((C, B) -> (C)) -> ((C, A) -> (C))
Despite the complexity, the compiler manages to catch two errors.
1. Closure use of non-escaping parameter `f` may allow it to escape
a. Automatic Fix-it by doing `f: @escaping (A) - > (B)`
2. Closure use of non-escaping parameter `reducer` may allow it to escape
b. No Fix-it provided <————
As you see above, the two places where a compile-time error occurred had the same exact problem; they both needed a `@escaping`. However, while the function parameter was offered an automatic fix-it, the nested closure being returned was not.
Here’s the correct version of the function.
func mapping <A, B, C> (f: @escaping (A) -> (B)) -> (@escaping ((C, B) -> (C))) -> ((C, A) -> (C)) {
return { reducer in
return { accum, input in
reducer(accum, f(input))
}
}
}
I know this is a small feature for a very specific use case but I think it could help make Xcode a little smarter :D
Thanks for reading!
AFAIK, fix-it is driven by the Swift compiler/source kit.
···
Le 13 juil. 2017 à 23:17, Saagar Jha via swift-evolution <swift-evolution@swift.org> a écrit :
You should probably file a Radar for this, since Xcode isn’t part of the Swift project.
Saagar Jha
On Jul 13, 2017, at 19:46, iCloud via swift-evolution <swift-evolution@swift.org <mailto:swift-evolution@swift.org>> wrote:
Hi Swift community,
I was wondering if we have considered adding support for providing Xcode automatic fix-it’s for closures being returned from a function.
For example, here is an incorrect version of a function that requires two `@escaping` keywords to be inserted.
func mapping <A, B, C> (f: (A) -> (B)) -> ((C, B) -> (C)) -> ((C, A) -> (C))
Despite the complexity, the compiler manages to catch two errors.
1. Closure use of non-escaping parameter `f` may allow it to escape
a. Automatic Fix-it by doing `f: @escaping (A) - > (B)`
2. Closure use of non-escaping parameter `reducer` may allow it to escape
b. No Fix-it provided <————
As you see above, the two places where a compile-time error occurred had the same exact problem; they both needed a `@escaping`. However, while the function parameter was offered an automatic fix-it, the nested closure being returned was not.
Here’s the correct version of the function.
func mapping <A, B, C> (f: @escaping (A) -> (B)) -> (@escaping ((C, B) -> (C))) -> ((C, A) -> (C)) {
return { reducer in
return { accum, input in
reducer(accum, f(input))
}
}
}
I know this is a small feature for a very specific use case but I think it could help make Xcode a little smarter :D
Thanks for reading!
On Jul 13, 2017, at 7:46 PM, iCloud via swift-evolution <swift-evolution@swift.org> wrote:
Hi Swift community,
I was wondering if we have considered adding support for providing Xcode automatic fix-it’s for closures being returned from a function.
For example, here is an incorrect version of a function that requires two `@escaping` keywords to be inserted.
func mapping <A, B, C> (f: (A) -> (B)) -> ((C, B) -> (C)) -> ((C, A) -> (C))
Despite the complexity, the compiler manages to catch two errors.
1. Closure use of non-escaping parameter `f` may allow it to escape
a. Automatic Fix-it by doing `f: @escaping (A) - > (B)`
2. Closure use of non-escaping parameter `reducer` may allow it to escape
b. No Fix-it provided <————
As you see above, the two places where a compile-time error occurred had the same exact problem; they both needed a `@escaping`. However, while the function parameter was offered an automatic fix-it, the nested closure being returned was not.
Here’s the correct version of the function.
func mapping <A, B, C> (f: @escaping (A) -> (B)) -> (@escaping ((C, B) -> (C))) -> ((C, A) -> (C)) {
return { reducer in
return { accum, input in
reducer(accum, f(input))
}
}
}
I know this is a small feature for a very specific use case but I think it could help make Xcode a little smarter :D
Thanks for reading!
On 2017년 7월 16일 AM 9:52 +0900, Félix Cloutier <felixcca@yahoo.ca>, wrote:
AFAIK, fix-it is driven by the Swift compiler/source kit.
> Le 13 juil. 2017 à 23:17, Saagar Jha via swift-evolution <swift-evolution@swift.org> a écrit :
>
> You should probably file a Radar for this, since Xcode isn’t part of the Swift project.
>
> Saagar Jha
>
> > On Jul 13, 2017, at 19:46, iCloud via swift-evolution <swift-evolution@swift.org> wrote:
> >
> > Hi Swift community,
> >
> > I was wondering if we have considered adding support for providing Xcode automatic fix-it’s for closures being returned from a function.
> >
> > For example, here is an incorrect version of a function that requires two `@escaping` keywords to be inserted.
> >
> > func mapping <A, B, C> (f: (A) -> (B)) -> ((C, B) -> (C)) -> ((C, A) -> (C))
> >
> > Despite the complexity, the compiler manages to catch two errors.
> >
> > 1. Closure use of non-escaping parameter `f` may allow it to escape
> > a. Automatic Fix-it by doing `f: @escaping (A) - > (B)`
> >
> > 2. Closure use of non-escaping parameter `reducer` may allow it to escape
> > b. No Fix-it provided <————
> >
> > As you see above, the two places where a compile-time error occurred had the same exact problem; they both needed a `@escaping`. However, while the function parameter was offered an automatic fix-it, the nested closure being returned was not.
> >
> > Here’s the correct version of the function.
> >
> > func mapping <A, B, C> (f: @escaping (A) -> (B)) -> (@escaping ((C, B) -> (C))) -> ((C, A) -> (C)) {
> > return { reducer in
> > return { accum, input in
> > reducer(accum, f(input))
> > }
> > }
> > }
> >
> > I know this is a small feature for a very specific use case but I think it could help make Xcode a little smarter :D
> > Thanks for reading!
> >
> >
> >
> >
> > _______________________________________________
> > swift-evolution mailing list
> > swift-evolution@swift.org
> > https://lists.swift.org/mailman/listinfo/swift-evolution
>
> _______________________________________________
> swift-evolution mailing list
> swift-evolution@swift.org
> https://lists.swift.org/mailman/listinfo/swift-evolution