[Haskell-cafe] Decorating exceptions with backtrace information
lemming at henning-thielemann.de
Tue May 12 20:55:08 UTC 2020
On Fri, 8 May 2020, Niklas Hambüchen wrote:
>> What are "unintended exceptions"?
>> What is an example of an "unintended exception"?
> A recent example from my production server:
> hPutBuf: resource vanished (Broken pipe)
Ok, I lookup the Haddock comment of hPutBuf and it says:
"This operation may fail with:
* ResourceVanished if the handle is a pipe or socket, and the reading end
That is, ResourceVanished is part of the public interface and in no way
unexpected (or what "unintended" may be). I would prefer to make this
explicit in the type of hPutBuf:
(ResourceVanishedException e) =>
Handle -> Ptr a -> Int -> ExceptT e IO ()
Now, what do you intend to do with the call-stack? Isn't it something you
can attach to the e value?
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