But I don't understand why it works

It's a hash slice.

@foo{@keys} = @values; looks like it's affecting @foo. But it isn't. It's affecting %foo

So $foo[0] affects $foo? No. The sigil indicates the value type, not the variable type. $foo[3] refers to the scalar value (thus the $) at element 3 of the array @foo.

@foo{qw( 1 2 3 )} = qw( a b c ); works the same as %foo = qw( 1 a 2 b 3 c );

Only if the hash is initially empty.

my %foo = qw( a 1 b 2 );
my %bar = qw( a 1 b 2 );

%foo = qw( c 3 d 4 );
@bar{qw( c d )} = qw( 3 4 );

print(join(' ', %foo), "\n");  # c 3 d 4
print(join(' ', %bar), "\n");  # a 1 b 2 c 3 d 4
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I have an intuition that this has to do with (de)referencing of typeglobs

No, no typeglobs involved, so it works equally well on lexical (my) variables as package (our) variables.

It's rather like the whole beginner array-vs-array-item confusion that so many people encounter, at least briefly: if @x is my array, surely item 3 in @x should be @x[3] ?

But of course it's not, it's $x[3] because the item itself is a scalar.

In this case, even though we're retrieving from (or in your case assigning to) a hash, we're interacting with it in a list-centric way rather than a one-thing-at-a-time way.

So @x{...} refers to %x. It has nothing to do with @x at al, and also nothing to do with typeglobs.

The trick is to understand that the kind of brackets around the index ({} vs []) determine whether it's an array or hash that you're dealing with, not the symbol at the front, which only determines how many things you're dealing with in one operation.

The short answer is that @array{1,2,3} is a hash slice, and therefore an array

That's wrong. It a hash slice, and it produces a list. It's not an array. Very different.

I admit, I've always thought that 'array' was just Perl's particular jargon for 'list'. Or maybe "Perl's data-structure for holding a list." If I write

@foo = (1,2,3)
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then @foo is an array, while (1,2,3) is a list. Right?

I find myself still confused on the distinction between an array and a list. Could you explain more?

throop