> On Jun 29, 2016, at 1:51 AM, Douglas Gregor <dgre...@apple.com> wrote:
>
> Do these associated types have meaningful defaults? We’re not talking about
> eliminating the ability to have default types for associated types, e.g.,
>
> public protocol ResourceController {
> associatedtype CreateInput
> associatedtype UpdateInput = CreateInput
>
> associatedtype ListOutput
> associatedtype CreateOutput = ListOutput
> associatedtype DetailOutput = ListOutput
> associatedtype UpdateOutput = ListOutput
>
> associatedtype DetailID
> associatedtype UpdateID = DetailID
> associatedtype DestroyID = DetailID
> }
>
> which might reduce the common case for conforming to the protocol to be, e.g.,
>
> extension TodoController : ResourceController {
> public typealias CreateInput = Todo
> public typealias ListOutput = Todo
> public typealias DetailID = String
> }
>
> - Doug
Unfortunately no. The whole purpose of having so many associated types is that
the user can simply chose the types he wants to use as the input and output of
each function required in the protocol.
public protocol ResourceController {
associatedtype CreateInput: StructuredDataInitializable
associatedtype UpdateInput: StructuredDataInitializable
associatedtype ListOutput: StructuredDataFallibleRepresentable
associatedtype CreateOutput: StructuredDataFallibleRepresentable
associatedtype DetailOutput: StructuredDataFallibleRepresentable
associatedtype UpdateOutput: StructuredDataFallibleRepresentable
associatedtype DetailID: PathParameterInitializable
associatedtype UpdateID: PathParameterInitializable
associatedtype DestroyID: PathParameterInitializable
func list() throws -> [ListOutput]
func create(element: CreateInput) throws -> CreateOutput
func detail(id: DetailID) throws -> DetailOutput
func update(id: UpdateID, element: UpdateInput) throws -> UpdateOutput
func destroy(id: DestroyID) throws
}
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