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Re: key/value hash and index/valuse array slices syntax

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From:
Eric Brine
Date:
June 10, 2013 21:53
Subject:
Re: key/value hash and index/valuse array slices syntax
Message ID:
CALJW-qHBkkxTZwSv6h-VbJKyvWJf=nJyRLk9v3iCZHrL_4rfHQ@mail.gmail.com
On Mon, Jun 10, 2013 at 4:17 PM, Lukas Mai <plokinom@gmail.com> wrote:

> On 10.06.2013 13:33, Dave Mitchell wrote:
>
>> On Sun, Jun 09, 2013 at 06:51:23PM -0500, David Nicol wrote:
>>
>>> one of the perl6 RFCs suggested allowing a regex as a hash index
>>>
>>>     @hash{/REGEX/}
>>>
>>> to mean
>>>
>>>    @hash{ grep /REGEX/, keys %hash }
>>>
>>
>> but that syntax already has a meaning:
>>
>>      %h = qw(aa 1 bb 2 cc 3);
>>      $_ = 'aa bb';
>>      print @h{/(\w+)/};  # prints 1
>>      print @h{/(\w+)/g}; # prints 12
>>
>>
> Right, but @hash{qr/REGEX/} could work. Currently it stringifies the regex
> object and uses that as a hash key, but that's not very useful IMHO.
>

No, it doesn't. Please reread the post to which you replied. There's no
stringification of the pattern, It's accessing the keys whose name is the
value of $1, $2, etc. after performing a match operation (against $_).

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