Hi,
Larry Wall wrote:
> On Sat, Jul 30, 2005 at 02:14:52PM +0200, Ingo Blechschmidt wrote:
> : http://use.perl.org/~autrijus/journal/25337:
> : > deref is now 0-level; $x = 3; $y = \$x; $y++. # now an exception
> :
> : my $arrayref = [1,2,3];
[...]
> : say $arrayref.isa("Ref"); # true or false?
>
> False, though tied($arrayref).isa("Ref") is probably true.
hm? I've probably misunderstood something, but I don't see any tied
variables in the snippet above -- so why should we use tied() to get at
the non-autodereffing ref of an autodereffing ref?
I thought tieing is a way to intercept further assignments -- i.e.
$some_tied_variable = ...;
will call user-defined code.
But this is not the case when dealing with simple references, right?
my $arrayref = [1,2,3];
# $arrayref contains an autodereffing Ref of Array now.
$arrayref = 42;
# $arrayref contains a simple Num now.
# The [1,2,3], which was previously stored in $arrayref,
# does not "notice" the new assignment.
Thus I propose we use tied() only to get at the underlying real contents
of a tied variable, and use
get_non_autodereffing_ref_out_of_autodereffing_ref() (with a shorter
name, of course), to convert an autodereffing ref to a
non-autodereffing ref.
my $arrayref = [1,2,3];
$arrayref.isa(Ref); # false
tied($arrayref); # error/undef
get_non_autodereffing_ref_out_of_autodereffing_ref($arrayref).isa(Ref);
# true
Opinions?
--Ingo
--
Linux, the choice of a GNU | To understand recursion, you must first
generation on a dual AMD | understand recursion.
Athlon! |
