Tom Christiansen wrote:
>
> And what about $$x?
>
> Dang, are we back to this incredible confusion about what it is to be
> defined in Perl.?
>
> undef $a;
>
> That is now UNINITIALIZED. So is this:
>
> $a = undef;
>
> You have initialized it to undef. There is no reasonable difference.
>
> Solution:
>
> Remove all references from the language to defined and undef.
> People just aren't smart enough to understand them. Change
> defined() to read has_a_valid_initialized_scalar_value(). Change
> undef() to "operator_to_uninitialize_a_variable". Touch luck
> on the chumps who can't type well. They pay for their brothers'
> idiocy.
>
> repeat until blue:
>
> INITIALIZED == DEFINED
> UNINITIALIZED == UNDEFINED
Thank you, that's a better way of describing part of the intent of this
RFC. I want to distinguish between variables that are uninitialized, and
expressions whose values are undefined.
my $x; # $x is uninitialized. Also, the value of $x is undefined.
undef $x; # $x has now been initialized. The value of $x is still
undefined.
This is *not* adding a new sort of value to perl. It is adding a
different state for the compiler to think of a variable as being in.
Initialization of a variable means you've done something that influenced
the value of that variable -- either by setting it, or blowing it away
and making it undefined.
You aren't interpreting the last part of the DESCRIPTION section ("you
need to do my $x= undef") as meaning that
my $x;
and
my $x = undef;
have a runtime difference, are you? I think this is confusing some
people, and I really shouldn't say "you would need to" do anything
different; I meant "you would need to say my $x = undef if you have this
warning turned on and you don't want to see it."
