# # -----Original Message-----
# # From: Tony Olekshy [mailto:[EMAIL PROTECTED]]
# # Sent: Tuesday, August 22, 2000 4:01 PM
# # To: [EMAIL PROTECTED]
# # Subject: Re: Exception stack: let's use the @@ list.
# # Peter Scott wrote:
# # >
# # > Brust, Corwin wrote:
# # > >
# # > > I've come to like @_ as our input list and think that
# # > > exception handling blocks would naturaly use this.
# # > >
# # > > Also it seems convienent, which seems perlish.
# # >
# # > I find myself indifferent on the subject of where the exception
# # > stack is stored (well, at least indifferent to the choices of @_
# # > and @@), even given the ramifications of each. I
would like to
# # > see each mentioned as alternatives; I don't mind which one is
# # > preferred.
# # Consider this case:
# # catch $@->{severity} eq "Fatal" => { ... }
# # Are you proposing to make @_ the exception stack in the catch
# # expressions too, as is:
nope, just B<within> C<catch>.
catch
map $@->isa($_), qw( list_o_classes ) # works, for me
{
warn; throw ; # but I like this better
then
warn "$@"; throw $@; # this
}
Doesn't it seems logical that the argument list would contain the exception
stack for block defined to handle exceptions?
# # Remember, these are expressions and blocks, *not* subs. In such
# # cases I excpect @_ to reflect the surrounding context, not magically
# # start to appear to be something different. I expect the following
# # to print B:
# # @_ = qw(A B C); try { ... } finally { print $_[1] }
which is right and good.
# # Remember RFC 88 + MOTIVATION + Rule 1:
# # 1. The ability to distinguish the normal control flow from
# # the exception handling flow to make the structure of the
# # program clear.
I guess I might prefer:
The ability to write exception handling code in (much) the same
manner as code which handles normal program behavior.
# # For many decades the telephone industry has *not* used normal phone
# # lines to send failure messages, because if the failure message is
# # that the line is down, well, you get the picture. Instead, they
# # have long relied on a seperate signalling channel. That's $@.
I that it's actually $! B<and> $@. but we are introducing something new to
per here. A code block specifically for the purpose of handling the
(previously?) global variable formerly known as $@. IMHO it is reasonable
to consider C<catch> a subroutine for that purpose.
The disadvantage of localizing @_ for the C<catch> block seems, to me,
outweighed by the consistency offer in keeping block input (clearly the
exception stack, for C<catch>) in @_.
# # -----Original Message-----
# # From: Peter Scott [mailto:[EMAIL PROTECTED]]
# # Sent: Tuesday, August 22, 2000 3:33 PM
# # To: Brust, Corwin; 'Tony Olekshy'; [EMAIL PROTECTED]
# # Subject: RE: Exception stack: let's use the @@ list.
[...]
# # the ramifications of each. I would like to see each mentioned as
# # alternatives; I don't mind which one is preferred.
That seems fine.
***
Much sorry if I seem to be getting snarky here, but I'm not much good at
arguing with people clearly more knowledgeable them myself.
-Corwin
