> Le 9 nov. 2017 à 08:57, Chris Lattner via swift-evolution > <swift-evolution@swift.org> a écrit : > > >> On Nov 6, 2017, at 4:13 AM, Jon Shier <j...@jonshier.com >> <mailto:j...@jonshier.com>> wrote: >> >> This consideration is further complicated by the possible addition of >> typed throws in the future. However, the most commonly suggested >> implementation fo typed throws keeps the ability for throws to be untyped. >> Additionally, the feature usually allows multiple types to be thrown from a >> single function. Result<T> can handle all of these scenarios automatically, >> since it reduces all errors down to Error. A Result<T, E> however, would >> either lose the ability to encapsulate any function with multiple error >> types, or otherwise have to wrap those cases in something like AnyError, in >> additional to having to do so in the untyped case. > > As I mentioned up-thread, this proposal isn’t going to go anywhere without a > proper discussion of typed throws. There are two possible designs that have > strong rationale: > > 1. Never add typed throws. > 2. Add the ability to specify a single type thrown (typically an enum, but > could be a struct), which defaults to Error if unspecified. > > In contrast, I don’t see any reason to add an arbitrary *list* of thrown > types, and I can’t imagine such a design happening. Swift already has ways > to specify alternatives (enums) and this would encourage exactly the behavior > from APIs that we want to avoid. > > This choice between 1/2 needs to be decided before introducing result, > because #1 means it should be Result<T>, and #2 means it should be > Result<T,E>. If this is important to you, I’d suggest starting a dedicated > discussion thread about the topic.
Hello, I wish that the Swift-Evolution discussion around typed / untyped throws would avoid three traps: - a bloodshed between pro and anti typed-throws - a pro-typed-throws echo chamber (since untyped throws is the passive status quo, and typed throws the energetic challenger) - even less average-joe-programmers than ever (on a topic that immensely impacts their everyday job) Shouldn't the community elect a benevolent dictator that would settle this subject? The final choice has of course to be sensible, but also strong and sharp. Gwendal
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