Roger, I think you slightly misunderstood me. ;-) It is true that `As` and `Is` methods can be used to allow `errors.As` and `errors.Is` to handle error types that aren't actually in the error chain.
However my question was if an `errors.Chain` function which returns details about the error types and values in the error chain would be a worthwhile addition to Go's `errors` package. On Wednesday, March 31, 2021 at 7:33:32 PM UTC+2 rog wrote: > On Wed, 31 Mar 2021 at 18:05, 'Michael Schaller' via golang-nuts < > golan...@googlegroups.com> wrote: > >> Hi everyone, >> >> I often encounter deep error chains where errors are wrapped across >> several Go packages and that makes it often hard to find a usable error >> type to use with `errors.As` or `errors.Is`. >> >> Could it make sense to add an `errors.Chain` function to Go that returns >> a slice with tuples of error type (reflect.Type) and the respective error? >> > > Unfortunately that's not possible in general because errors in the change > can implement their own `As` and `Is` methods, so an error can appear > to have some type T in the chain (i.e. errors.As(new(T)) returns true) > without *actually *having that type in the chain. > > For example: https://play.golang.org/p/-IAKMrD8FlG > > It's a shame in my view, but that's what we've got. > > cheers, > rog. > > >> Quick example: >> https://play.golang.org/p/hDW0_6P7O2Y >> >> Best, >> >> Michael >> >> -- >> You received this message because you are subscribed to the Google Groups >> "golang-nuts" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to golang-nuts...@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/golang-nuts/acab291d-21bc-4c84-a19a-7f9901cc8035n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/golang-nuts/acab291d-21bc-4c84-a19a-7f9901cc8035n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/9aed0787-8a5f-4b1b-ab18-ee654418340an%40googlegroups.com.
