Re: some proposed changes

[Huw Rogers <count0 building2 co jp>]

So an appropriate warning when a type mismatch occurs and -w is in
effect, together with appropriate promotion / upcasting /
autovivification?

I'd like to apply that consistently throughout.

	-Huw

> 
> Huw Rogers <count0 building2 co jp> writes:
> 
> > > > 
> > > > Huw Rogers <count0 building2 co jp> writes:
> > > > > * if a sequence is undef, it is marshalled as a zero length sequence.
> > > > > Right now if it is not a true reference to an array it dies.
> > > > 
> > > > I don't agree with this at all.
> > > > 
> > > >  $a = []; print scalar (@$a), "\n";
> > > >  $a = undef; print scalar (@$a), "\n";
> > > > 
> > > > Are very different; the second one is a warning. 
> > > > 
> > > > Allowing this would be similar to allowing "undef" to be marshalled as
> > > > an empty string without any warning, which is similar to thinking
> > > > in C that "" is the same as NULL. <shudder>
> > > 
> > > The sequence marshalling of undef is the most dubious of my proposals,
> > > and I guess I should retract it.
> > 
> > Having said that,
> > 
> > $a = []; print scalar (@$a), "\n";
> > $a = undef; print scalar (@$a), "\n";
> >
> > results in: "0" and "" being printed with no warnings.
> 
> $ perl -we '$a = undef; print scalar (@$a), "\n";'
> Use of uninitialized value in array dereference at -e line 1.
> Use of uninitialized value in print at -e line 1.
> 
> Perhaps you weren't testing with -w ... but programming Perl
> without -w is akin to mountain climbing without a safety
> rope...
> 
> > In general, I'd like things to behave in a Perl like fashion, including
> > "auto-vivification" of CORBA data structures as necessary.
> 
> I certainly agree things that things should behave in
> a Perl-like fashion; so I think it's not a big problem if
> undef marshals like []. *but* it needs to generate a warning
> when -w is used if you allow that.

-- 
Huw Rogers <rogers building2 co jp>