Using Result with Alamofire about result

[kgaidis]

Wanted to reference this workaround for people who have problems in the future:
Alamofire/Alamofire#1271 (comment)

import enum Result.Result
import Alamofire

[kgaidis]

To note, the above solution import enum Result.Result for some reason fails when trying to build for Release. Swift compiler had an error: no such "decl" in module

The ResultResult doesn't seem to be the most flexible either, got error in a protocol:
Cannot specialize non-generic type JsonResult (aka 'Result<String, NSError>')

While it might be a Swift bug, the pain is pretty real.

I'll get my workarounds, but it isn't too intuitive for anyone who is relatively new to Swift (and/or iOS). It be nice for this issue to be open, or at least clearly documented. Alamofire is one of the most popular libraries so the chance of encountering this problem is relatively high.

[neilpa]

You'll have to use the fully qualified name Result.Result<MyDataType, MyErrorType> to avoid the ambiguity.

[kiliankoe]

That seems logical, but Xcode doesn't interpret this correctly and is complaining.

Reference to generic type 'Result' requires arguments in <...>

[robrix]

This is a Swift bug:

• http://openradar.appspot.com/19774567
• http://openradar.appspot.com/20633559

[kiliankoe]

Ah, thank you. I'll be duping that then :)

I guess this issue can be closed if it'll hopefully be resolving itself soon?

[MrAlek]

I ran into the same issue. Until the radars are fixed, a work-around is to make your own struct with a type-alias in a separate file.

// ResultResult.swift
import Foundation
import Result

// TO-DO: As soon as https://github.com/antitypical/Result/issues/77 is resolved, this file should be removed
struct ResultResult<T, Error : ErrorType> {
    typealias t = Result<T, Error>
}

// API.swift
import Foundation
import Alamofire

typealias StringResult = ResultResult<String, NSError>.t

Works like a charm!

[kiliankoe]

That's a nifty workaround, thanks!

[hiragram]

@kiliankoe @MrAlek
Is the bug of swift resolved? or still needs ResultResult?

[robrix]

Swift still has this bug.

[hiragram]

thx