[swift-evolution] Adding Result to the Standard Library

[Nick Keets]

Right, to me there is not a lot of value in adding Result as it exists in
AlamoFire. We will (eventually) use the Swift Package Manager for things
like this. The value would be in integrating it like Optionals. e.g. (using
a strawman symbol)

    var x: Int‽ = 5
    var y: Int‽ = anErrorValue

    func foo() -> Int‽ { ... }

    if let x = foo() {
        // x is Int
    } else {
        // somehow access the error
    }

    guard let x = foo() else {
        // Again somehow access the error
    }

    func bar() throws -> String { ... }
    let x = try‽ bar()   // x is String‽
    let y = x!  // y is String

    // Possibly even make it throw? (just using a random symbol again)
    let z = try x¡


On Fri, Nov 3, 2017 at 2:02 AM, Xiaodi Wu via swift-evolution <
swift-evolution at swift.org> wrote:

> This is clearly a fine addition to the standard library; even Swift's
> Error Handling Rationale (https://github.com/apple/swift/blob/master/docs/
> ErrorHandlingRationale.rst) mentions such an addition
>
> What separates standard library types from other types is that they have
> language level support, and the wrapping and unwrapping syntax here could
> definitely benefit from it (`.unwrap()`--which should be `.unwrapped()`
> incidentally--is so much less elegant in comparison to `?` and `!` for
> optionals (not that `Result` should use the exact such syntax for a
> distinct operation)). It would be a shame to transpose a third-party
> `Result` to the standard library without considering if any such tweaks
> would substantially improve ergonomics, interconversion with Optional and
> throws, etc.
>
>
> On Thu, Nov 2, 2017 at 1:08 PM, Jon Shier via swift-evolution <
> swift-evolution at swift.org> wrote:
>
>> Swift-Evolution:
>> I’ve written a first draft of a proposal to add Result<T> to the standard
>> library by directly porting the Result<T> type used in Alamofire to the
>> standard library. I’d be happy to implement it (type and tests for free!)
>> if someone could point me to the right place to do so. I’m not including it
>> directly in this email, since it includes the full implementation and is
>> therefore quite long. (Discourse, please!)
>>
>> https://github.com/jshier/swift-evolution/blob/master/propos
>> als/0187-add-result-to-the-standard-library.md
>>
>>
>> Thanks,
>>
>> Jon Shier
>>
>>
>>
>> _______________________________________________
>> swift-evolution mailing list
>> swift-evolution at swift.org
>> https://lists.swift.org/mailman/listinfo/swift-evolution
>>
>>
>
> _______________________________________________
> swift-evolution mailing list
> swift-evolution at swift.org
> https://lists.swift.org/mailman/listinfo/swift-evolution
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.swift.org/pipermail/swift-evolution/attachments/20171103/3257baea/attachment.html>