Marton, I am not sure of your meaning. I took the warning message as:
For Scalars assign a Nil, for Arrays/Hashes/Etc. use Empty or ().
Because you might be read as suggesting "@ary = Nil should undefine @ary";
I will point out that will conflict with:
@a = Nil;
which is defined to assign the RHS entry to the first element of @a.
I suspect there is no way to destroy a container but to smash it into
a scope wall.
Some day I shall get serious about understanding Raku's containers.
In the meantime, I'll just keep creeping up on them and observing.
Rob
On Tue, Mar 14, 2023 at 01:38:22PM +0100, Polgár Márton wrote:
> On 2023. 03. 14. 4:42, rir wrote:
> > undefine seen at:
> > <unknown file>, line 1
> > Will be removed with release v6.e!
> > Please use another way: assign a Nil; for Arrays/Hashes, assign Empty
> > or () instead.
> >
> > Will that deprecation require a conditional and two assignments
> > for mixed data?
> >
> > [$a, @a, $b, %c, $c, &d].map: { .&undefine};
> >
> > [$a, @a, $b, %c, $c, &d].map(
> > { $_ = $_ ~~ (Associative,Positional).any ?? Empty !! Nil });
>
> And even those ways don't seem too convincing... after all, it's more a
> question of containerization if assigning Nil will cut it or not. I didn't
> know about undefine but it appeared to me as an issue that you can just
> assign Nil to an Array and get something that is not the default value -
> moreover, it doesn't even evaluate to boolean False!
>
> It seemed like something that can wait and that could cause a lot of
> friction as a breaking change but I think it would make overwhelmingly more
> sense to make Nil always set the default. It is a special value of a special
> singularity type on its own; it's questionable whether it should ever appear
> as an assigned element of a composite container but to make it STORE in a
> special, resetting way, seems kind of a no-brainer, apart from the
> "breakage"...
