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Posted to modperl@perl.apache.org by will trillich <wi...@serensoft.com> on 2001/05/04 02:46:58 UTC
Re: mod_perl subs defined, but don't exist? SOLVED mostly
On Thu, May 03, 2001 at 01:19:45AM -0500, will trillich wrote:
> On Thu, May 03, 2001 at 12:29:53AM -0500, will trillich wrote:
> > long version--
> >
> > I have a subroutine that IS DEFINED, but it's not showing up as
> > defined. I used the *Symbol::Table::name{CODE} method myself and
> > sure enough, there's no CODE for the defined subroutine...
>
> [snip]
>
> > ANY wild-ass guesses would be appreciated. (Do i win a prize for
> > the most difficulty with a simple situation? Or at least an
> > honorable mention for most belligerent refusal to move on and get
> > a life?)
> >
> > ###########################################
> >
> > short version--
> >
> > WTF?
>
> how can a defined subroutine NOT have any code in the symbol
> table? grr! this is quite a puzzle...
okay, here was the problem.
package My::Debacle;
sub search {
# ....
{
use CGI qw/:standard/;
my $form = join '',
map {
hidden(
-name => $_,
-value => $arg->{$_},
) . "\n"
}
grep(
$arg->{$_} and ($_ ne 'd') and ($_ ne 'go')
, keys %$arg
)
;
# ....
}
# ....
}
sub this { # ...
}
sub that { # ...
}
sub something_else { # ...
}
sub whatever_the_hell { # ...
}
sub handler { # ...
}
can you spot the problem?
with that, poof! $My::Debacle::handler{CODE} doesn't exist.
WHY?
--
will@serensoft.com
http://sourceforge.net/projects/newbiedoc -- we need your brain!
http://www.dontUthink.com/ -- your brain needs us!
Re: [OT] Re: mod_perl subs defined, but don't exist? SOLVED mostly
Posted by will trillich <wi...@serensoft.com>.
On Fri, May 04, 2001 at 12:29:30AM -0500, Ken Williams wrote:
> will@serensoft.com (will trillich) wrote:
> > > sub search {
> > > # ....
> > > {
> > > use CGI qw/:standard/;
> > > my $form = join '',
> > > map {
> > > hidden(
> > > -name => $_,
> > > -value => $arg->{$_},
> > > ) . "\n"
> > > }
> > > grep(
> > > $arg->{$_} and ($_ ne 'd') and ($_ ne 'go')
> >
> >as is, the functions that follow (top-level 'sub xyz {}') get
> >screwy. code disappears.
> >
> >replace "and" with "&&" and all is well. boggles my mind.
>
>
> Well, as far as I can tell, the original code doesn't even compile
> because there aren't enough arguments to grep(). That's why I couldn't
> test it.
grep(
$arg->{$_} and ($_ ne 'd') and ($_ ne 'go')
, keys %$arg # note the leading comma...
)
aha -- so maybe "x and y and z , pdq" has lexical precedence
where the (z,pdq) parses higher, as in
x and y and (z , pdq)
versus what i expected, which was
(x and y and z) , pdq
hmm?
--
will@serensoft.com
http://sourceforge.net/projects/newbiedoc -- we need your brain!
[OT] Re: mod_perl subs defined, but don't exist? SOLVED mostly
Posted by Ken Williams <ke...@forum.swarthmore.edu>.
will@serensoft.com (will trillich) wrote:
> > sub search {
> > # ....
> > {
> > use CGI qw/:standard/;
> > my $form = join '',
> > map {
> > hidden(
> > -name => $_,
> > -value => $arg->{$_},
> > ) . "\n"
> > }
> > grep(
> > $arg->{$_} and ($_ ne 'd') and ($_ ne 'go')
>
>as is, the functions that follow (top-level 'sub xyz {}') get
>screwy. code disappears.
>
>replace "and" with "&&" and all is well. boggles my mind.
Well, as far as I can tell, the original code doesn't even compile
because there aren't enough arguments to grep(). That's why I couldn't
test it. I suppose changing the precedence helped things out. Perhaps
you should use the more explicit BLOCK version:
my $form = join '',
map
{
hidden(
-name => $_,
-value => $arg->{$_},
) . "\n"
}
grep
{
$arg->{$_} and ($_ ne 'd') and ($_ ne 'go')
}
keys %$arg;
>
>with 'and' *{$My::Debacle::{handler}}{CODE} doesn't exist.
That's an illusion. The truth is that with 'and' the code is checking
something completely different, or not working at all.
This is turning out to be pretty well off-topic for the mod_perl list,
so we should cease.
------------------- -------------------
Ken Williams Last Bastion of Euclidity
ken@forum.swarthmore.edu The Math Forum
Re: mod_perl subs defined, but don't exist? SOLVED mostly
Posted by will trillich <wi...@serensoft.com>.
On Thu, May 03, 2001 at 08:52:38PM -0500, Ken Williams wrote:
> I can't follow this test case. Your previous message had a test case,
> but it was way too big. Can you whittle this down into the smallest
> possible program that demonstrates something you don't understand, and
> post that? My guess is that you'll figure out the problem in the
> process, but if not, post it here.
i found the culprit, but it's like finding out that a butterfly
burned down your house. i still don't see how it's possible.
when i distill it, of course, the problem vanishes. but see
below--
> By the way, I don't think you mean $My::Debacle::handler{CODE}. If you
> look closely, you'll see that it's just a regular hash entry. I think
> you mean *{$My::Debacle::{handler}}{CODE}. That's the CODE component of
> a symbol table entry.
right. whoops. boy, that stuff gets deep, quick.
> If you have "Effective Perl Programming", look on page 239.
eagle book, camel book, but no "shiny ball book". yet. :)
> I know this stuff is hard to spot when you've been banging your head
> against it for days. For that, I recommend "Zen and the Art of
> Motorcycle Maintenance".
a very good read, that.
> will@serensoft.com (will trillich) wrote:
> >okay, here was the problem.
> >
> > package My::Debacle;
> >
> > sub search {
> > # ....
> > {
> > use CGI qw/:standard/;
> > my $form = join '',
> > map {
> > hidden(
> > -name => $_,
> > -value => $arg->{$_},
> > ) . "\n"
> > }
> > grep(
> > $arg->{$_} and ($_ ne 'd') and ($_ ne 'go')
as is, the functions that follow (top-level 'sub xyz {}') get
screwy. code disappears.
replace "and" with "&&" and all is well. boggles my mind.
> > , keys %$arg
> > )
> > ;
> > # ....
> > }
> > # ....
> > }
> >
> > sub this { # ...
> > }
> > sub that { # ...
> > }
> > sub something_else { # ...
> > }
> > sub whatever_the_hell { # ...
> > }
> > sub handler { # ...
> > }
with 'and' *{$My::Debacle::{handler}}{CODE} doesn't exist.
i've got a similar snag in a different module, now, where defined
subs are disappearing. but i can't trace it to a stray 'and'
here... must be something deeper?
--
will@serensoft.com
http://sourceforge.net/projects/newbiedoc -- we need your brain!
Re: mod_perl subs defined, but don't exist? SOLVED mostly
Posted by Ken Williams <ke...@forum.swarthmore.edu>.
I can't follow this test case. Your previous message had a test case,
but it was way too big. Can you whittle this down into the smallest
possible program that demonstrates something you don't understand, and
post that? My guess is that you'll figure out the problem in the
process, but if not, post it here.
By the way, I don't think you mean $My::Debacle::handler{CODE}. If you
look closely, you'll see that it's just a regular hash entry. I think
you mean *{$My::Debacle::{handler}}{CODE}. That's the CODE component of
a symbol table entry.
If you have "Effective Perl Programming", look on page 239.
I know this stuff is hard to spot when you've been banging your head
against it for days. For that, I recommend "Zen and the Art of
Motorcycle Maintenance".
will@serensoft.com (will trillich) wrote:
>okay, here was the problem.
>
> package My::Debacle;
>
> sub search {
> # ....
> {
> use CGI qw/:standard/;
> my $form = join '',
> map {
> hidden(
> -name => $_,
> -value => $arg->{$_},
> ) . "\n"
> }
> grep(
> $arg->{$_} and ($_ ne 'd') and ($_ ne 'go')
> , keys %$arg
> )
> ;
> # ....
> }
> # ....
> }
>
> sub this { # ...
> }
> sub that { # ...
> }
> sub something_else { # ...
> }
> sub whatever_the_hell { # ...
> }
> sub handler { # ...
> }
>
>can you spot the problem?
>
>with that, poof! $My::Debacle::handler{CODE} doesn't exist.
>WHY?
>
>--
>will@serensoft.com
>http://sourceforge.net/projects/newbiedoc -- we need your brain!
>http://www.dontUthink.com/ -- your brain needs us!
>
------------------- -------------------
Ken Williams Last Bastion of Euclidity
ken@forum.swarthmore.edu The Math Forum