Hi Jaromir,

We should start with a test case. I agree with your interpretation of
the standard and see no harm in an inbox submission.
Is there some ANSI Smalltalk test suite out there that could be shared
between the dialects?

As so often, the breaking of applications that relied on the
non-standard behavior may be an obstacle.

Kind regards,
Jakob

Am Sa., 29. Jan. 2022 um 17:43 Uhr schrieb <mail at jaromir.net>:
>
> Hi all,
>
> I think Squeak's implementation of #resignalAs: is not following the ANSI specification precisely. Currently it reads:
>
> resignalAs: replacementException
>
>         signalContext resumeEvaluating: [replacementException signal]
>
> ANSI says:
> "
> The active exception action is aborted and the exception environment *and the evaluation context*
> are restored to the same states that were in effect when the receiver was originally signaled.
> This message (i.e. resignalAs:) causes the replacementException to be treated as if it had been originally
> signaled instead of the receiver.
> "
>
> This is very similar to #retry (or #retryUsing:) specification so I'd suggest the following implementation:
>
> resignalAs: replacementException
>
>         signalContext restartWithNewReceiver: replacementException
>
> The current implementation leads to building the new resignaled contexts on top of the previous signal contexts (and the resignalAs context itself) instead of simply *restarting* the previous signal context with the replacement exception as the new receiver. In my opinion the suggested implementation precisely follows the ANSI specification, and is consistent with current #retry and #retryUsing: implementation - compare:
>
> retryUsing: alternativeBlock
>         "Abort an exception handler and evaluate a new block in place of the handler's protected block."
>
>         handlerContext restartWithNewReceiver: alternativeBlock
>
> Other dialects: Pharo and Cuis copied Squeak's but VW implemented resignalAs: to comply with ANSI precisely.
>
> One consideration: the current implementation allows "exception resignalAs: Error", i.e. allows Exception class as an argument but ANSI's version requires "exception resignalAs: Error new". All senders (there are just a few) in the base image seem use "Error new" anyway.
>
> My arguments for are: consistency, readability and less complexity (especially while debugging)
>
> What do you think? Inbox it?
>
> best,
> ~~~
> ^[^    Jaromir
>
> Sent from Squeak Inbox Talk
>