> On Feb 21, 2017, at 8:18 AM, Joe Groff <jgr...@apple.com> wrote:
>>>
>>
>> Yeah but Rust has a macro system so error-chain makes re-wrapping trivial. A
>> simple `chain_err(|| “my new error message”)` is enough to define and
>> “throw” a new error that wraps the underlying error.
>
> That was my point—they recognized error chaining/layering as a common
> phonemenon and provided affordances for it as part of their design. I was
> saying we should do the same if we investigate typed errors seriously. (Not
> sure why you mentioned macros—chain_err is just a regular method, and could
> be defined as an extension method on Error in swift today.)
>
> -Joe
Sorry, I meant error_chain! handles the boilerplate. At the end of the day
something has to create the new error types.
I agree with you on the chaining; if we really do want to go down this road we
need an elegant solution. Seeing people talk about getting rid of rethrows
makes me think this isn’t yet a serious discussion.
Russ
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