From: Dan Doel <djd15@...>
Date: 2004-04-04T23:02:14+09:00
Subject: Re: Any chance to see Exception#resume in Ruby2 ?

As I recall, this was discussed here before and it was decided that it was a
bad idea.

The argument went something like this:

When you throw an exception, you do so to indicate some sort of error.
Generally, this means that execution after that point can't continue, so
#resume doesn't make sense.  The most you can do is retry, which starts
back at the beginning of the sequence of events to try the whole operation
over again.

I think the argument for it was that you could encounter a non-fatal error
condition, throw an exception to skip out, log the error, and skip back in
to continue down some alternate path.  However, this isn't always possible,
and you have to specifically code for it.

So you'd have libraries that support resumable exceptions, and libraries
that don't, and trying to resume in one that doesn't causes big problems.
I think the general consensus was that Exceptions are supposed to
represent unrecoverable error conditions, so you couldn't resume. I
suppose you could implement some sort of recoverable exception using
continuations, but it might be ugly (actually, I'll think about it and see
what I can come up with).

Basically, Matz said it wouldn't be put in.

- Dan