On Mar 12, 2009, at 12:52 AM, Chas. Owens wrote:
On Thu, Mar 12, 2009 at 01:27, Chap Harrison <c...@pobox.com> wrote:
It's still not intuitive to me why we FIRST "convert" the hash to
an array,
and THEN ask for keys - keys being hash-ish, rather than array-ish
sorts of
things. (I've said that badly.) What exactly are the elements of
the array
@{$hash{adams...@keys} ?
snip
It isn't really becoming an array. A better way to think of it is
that $ means we expect one value back from the data structure:
Let me break this expression down according to my current understanding.
@{$hash{adams...@keys} = @values;
parses as follows:
adams : short for 'adams', a string literal, being used as a hash key
$hash{adams} : the value in the hash associated with 'adams', a scalar
(always), and a ref to a hash in this case
{$hash{adams}} : extra braces, used to force correct "binding" (?)
with surrounding context, I expect.
{$hash{adams...@keys} : the hashref is dereferenced, and a set of keys
(provided by an array) is looked up in the hash, resulting in a set of
values; or, more precisely, *aliases* of values.
@{$hash{adams...@keys} : an array of aliases of the hash values
associated with the keys supplied in @keys.
@{$hash{adams...@keys} = @values : behaves much like...
( $hash{adams}{a}, $hash{adams}{ar}, $hash{adams}{af}, $hash{adams}
{aw} ) = ( 1, 19, 13, 11 )
So that's my own badly-described understanding of how that expression
does what it does. I'd greatly appreciate any corrections.
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