What is this magic?

toasty has asked for the wisdom of the Perl Monks concerning the following question:

From Regexp::Common::zip

$RE{zip}{US}{-extended => [yes|no|allow]}
[download]

What is going on with {-extended => [yes|no|allow]}?

It kinda looks like a hash slice, but it's not, right? How is that syntax able to set an option?

Might be a simple answer, just puzzles me this afternoon.

Comment on What is this magic? Select or Download Code

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Re: What is this magic? by ikegami (Patriarch) on May 21, 2009 at 20:00 UTC
When multiple indexes are provided as a hash index (as opposed to a hash slice), they are joined using `$;`. This is indeed a rarely used feature. (HoH are preferred.) `$ perl -wle'$h{ -extended => "no" } = 1; print for keys %h' \| od -c 0000000 - e x t e n d e d 034 n o \n 0000015` [download] How is that syntax able to set an option? `%{ $RE{zip}{US} }` is either magical (and the fetcher looks for `/^-extended\034/`) or it's populated with all the possible options.	[reply] [d/l] [select]
Re^2: What is this magic? by toasty (Novice) on May 21, 2009 at 20:54 UTC
Thanks indeed for satisfying my curiosity. Long time hacker, never saw it before today.	[reply]