1

to me protocol extensions are both cool and evil. cool as you can add code.
evil because it's more natural to add another declarations in those
extensions rather than implementation:

protocol Foo {
    func foo()
}

extension Foo {
   func bar() //*** natural assumption is that i can do this. but i can't
}

i'd say, abusing "extension protocol" syntax to add code looks like a
(cool) hack and my +1 would be for some other more explicit syntactic
construct for the purposes of adding code, for example:

implementation Foo {
    func foo() {
        ...
    }
}

Mike

···

on Sun, 5 Nov 2017 09:27:09 +0000 Goffredo Marocchi <panajev@gmail.com> wrote:

I would say that you kind of already entered a slippery slope when the
extension to a protocol can add code / not just declare a behavioural
contract ...

2

to me protocol extensions are both cool and evil. cool as you can add code. evil because it's more natural to add another declarations in those extensions rather than implementation:

protocol Foo {
    func foo()
}

extension Foo {
   func bar() //*** natural assumption is that i can do this. but i can't
}

After a moment of reflection, I think I understand your reasoning — but why should you want to do this?
Imho splitting types with extensions is already overused quite often, but splitting a protocol makes no sense for me at all.

3

the use case would be splitting my own big protocols into different parts
for code organizing purposes (so it's within the module boundaries).

Mike

···

On 6 November 2017 at 19:44, Tino Heth <2th@gmx.de> wrote:

to me protocol extensions are both cool and evil. cool as you can add
code. evil because it's more natural to add another declarations in those
extensions rather than implementation:

protocol Foo {
    func foo()
}

extension Foo {
   func bar() //*** natural assumption is that i can do this. but i
can't
}

After a moment of reflection, I think I understand your reasoning — but
why should you want to do this?
Imho splitting types with extensions is already overused quite often, but
splitting a protocol makes no sense for me at all.