Re^4: Inline substitution regex

[vitoco]

in reply to Re^3: Inline substitution regex
in thread Inline substitution regex

Just guessing, shouldn't the solution be:

foreach (keys %{$ref_cookie}) {
    push @{$self->{cookies}}, /^-(.*)/, $ref_cookie->{$1});
}

?

Or the curly brackets from the failing original code isolate $_ and the substitution does not affect the last parameter of push?

# push(@{$self->{cookies}}, {$_=~s/^-//}, $ref_cookie->{$_}});

[ikegami]

Your solution is definitely buggy.

Let's say %$ref_cookie contains

-foo => 'food',
-bar => 'bard'

The solution you propose would push

'foo', undef, 'bar', undef
    -or-
'bar', undef, 'foo', undef

(depending on the order the keys are returned)

That's obviously not what he wants. He would just use undef if so.

Fine, you'll say %$ref_cookie should contain

-foo => 'food',
foo  => 'fool',
-bar => 'bard',
bar  => 'barl'

The solution you propose would push

'foo', 'fool', 'fool', 'bar', 'barl', 'barl'
    -or-
'foo', 'fool', 'fool', 'fool', 'bar', 'barl'
    -or-
undef, undef, 'bar', 'barl', 'foo', 'fool'
    -or-
...

(depending on the order the keys are returned)

It makes no sense. I suspect the OP wants

'foo', 'food', 'bar', 'bard'
    -or-
'bar', 'bard', 'foo', 'food'

(depending on the order the keys are returned)

That is achieved using the solution I proposed.

[vitoco]

Wow, that was an unexpected answer... :-)

With post "I should've known better!" in mind, I was trying to understand if $_ is modified only in the scope of the substitution from the OP's attempt:

foreach (keys %{$ref_cookie}) {
  push(@{$self->{cookies}}, {$_=~s/^-//}, $ref_cookie->{$_}});
}

I didn't pay much attention on the context or what keys should be. I see your point and agree.

Now, if OP has both types of keys, with and without leading hashes:

-foo => 'food',
bar  => 'barl'

the code should be:

  push @{$self->{cookies}}, /^-?(.*)/, $ref_cookie->{$_};

to get all four values in the array.

BTW, I'll have to practice more with push of undef in arrays...

[ikegami]

I had only answered your first question. As for your second question, no, the hash creation operator ({}) does not localize $_. Curlies don't localize $_ when they're used as a bare block either. And neither does do. $_ is only implicitly localized by foreach loops (when no iterator variable is provided), map and grep.