On Jun 29, 2016, at 2:33 PM, Daniel Dunbar via swift-users <swift-users@swift.org> wrote: > > I would like some clarification regarding the expected role of > `CustomStringConvertible` for types which have a natural, lossless, string > representation.
And this is why we started down the road towards clarifying that it wasn't convertible but a lossy representation. What you really want is a protocol that represents an isomorphic relationship. RawRepresentable is about as close as you can get right now. And "representation" in RawRepresentable actually means "isomorphic conversion between types". (ish.) -- E, paging Matthew Johnson to the SE-0041 courtesy phone p.s. https://github.com/apple/swift-evolution/blob/master/proposals/0041-conversion-protocol-conventions.md > I don't have good terminology to use here, but is the expectation that the > "textual string representation" is a readable description of the object? This > seems to correspond to the synthesized (?) default definition for struct > types, as well as some of the uses for Foundation types without natural > string representations (i.e. `Foundation.Notification` reports something like > "name = foo, object = ..., userInfo = ..."). > > Or, is the expectation that it provide a string *representation* of the > object, for objects where that makes sense. This corresponds to the use in > `Foundation.UUID`, or the example of `Point.description` from the stdlib's > `CustomStringConvertible` documentation. > > Another way of phrasing this question is: for types which have a reversible > string representation, should I expect `CustomStringConvertible.description` > to give me a string I could use to reconstruct an instance _without_ knowing > its type? > > And another way (my actual question) is, given a `struct Path` object which > contains a path string, what should `print(Path("a"))` print? > > - Daniel > > _______________________________________________ > swift-users mailing list > swift-users@swift.org > https://lists.swift.org/mailman/listinfo/swift-users _______________________________________________ swift-users mailing list swift-users@swift.org https://lists.swift.org/mailman/listinfo/swift-users
