[erlang-questions] Old school exceptions vs. new age one
Tue Apr 29 16:59:40 CEST 2008
Tony Finch wrote:
>> On the contrary - the exception handling in ML lacks the
>> success-case branch that you get in Erlang with try...of...
>> (hence, it is ML that needs to be turned into Erlang). :-)
> You have probably seen this paper which does just that:
Yes. I hadn't seen it when we did our work on try/catch and wrote our paper,
though, and Phil Wadler who was on the Workshop committee didn't recall the
Benton & Kennedy paper either, until some months afterwards (he then pointed
me to their paper and vice versa, which was very nice of him).
The background is that B&K was published in 2001, and by then we had been
talking about try/catch for a couple of years - practically since the
C++-like suggestion by Barklund in ~1998 (which turned out to be problematic
when we tried to implement it), and we weren't on the lookout for papers
with sudden, new solutions to a rather old problem. I can trace the
"try...of..." syntax in our repository to January 2003 (if anyone's
interested - It's not that I feel that I need to defend anything).
I can remember drawing a diagram of the control flows on my whiteboard and
thinking "what is missing in this picture", and going "hey...". And then I
realized that the corresponding syntax was much like what a chap had
suggested in passing during a workshop a couple of years before (maybe he
had read B&K?), which I had dismissed as "easy to do using a temporary
constructor". Sometimes, it seems, it's just that the time for an idea has
arrived. Reading B&K could have saved me some work, though.
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