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Re: map problem

by moritz (Cardinal)
on Mar 09, 2012 at 10:57 UTC ( #958676=note: print w/ replies, xml ) Need Help??

in reply to map problem

This is another instance of the problem that a pair of curlies can stand for an anonymous subroutine or a hash reference. You can disambiguate with a semicolon in the block:

my %y = map {; "prefix_$_" => 1 } qw(a b c);

It's more of a design limitation than a bug in perl or in you :-)

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Re^2: map problem
by morgon (Deacon) on Mar 09, 2012 at 11:01 UTC
    Ok, but why is it neccessary only in the second case?

      The decision to parse an opening curly bracket as a block or a hash ref is really just a heuristic. When the parser sees a string quote, it decides in favor of the hash ref, whereas a variable makes it assume a block.

      Or put differently, the parser cheats as hell, and sometimes that backfires. But not always.

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