in reply to How to call a sub-routine ref

I like the second one better, and don't see how it would be more confusing than the first one.

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Re^2: How to call a sub-routine ref
by greengaroo (Hermit) on Oct 19, 2012 at 20:16 UTC

    Imagine this:

    &{$hashref->{'key'}}('key');

    vs.

    $hashref->{'key'}->('key');

    Don't you think the second could lead to confusions?

    I'm just trying to find what is best, I honestly prefer the first but I've never seen it until recently, so I am thinking maybe no one uses it because it may be harder to understand at first sight.

    There are no stupid questions, but there are a lot of inquisitive idiots.

      For that particular case, you don't need either the -> or the &{}:

      sub x{ say "x got [ @_ ]"; };; $h{x} = \&x;; $href = \%h;; $href->{x}('fred','bill');; x got [ fred bill ]

      With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.

      RIP Neil Armstrong

      greengaroo:

      Odd, I find your examples a good case for using the second one. Again, different people will find different things more clear.

      When I use hashes, I generally use $$h{foo} in preference to $h->{foo}, primarily because it's easier to type, and I use hashes quite a bit. If I were trying to make it visually distinctive, I'd make the harder to type one be for the less frequently used case. Thus, I'd use something like:

      $$hashref{key}->('arg');

      To my eye, that stands out better. (But with my luck, it would blow up, so I'd better whip up a test...)

      $ cat t.pl use strict; use warnings; sub p { print "foo(", join(", ", @_), ")\n"; } my $hr = { key=>\&p }; $$hr{key}->('arg'); $ perl t.pl foo(arg)

      ...roboticus

      When your only tool is a hammer, all problems look like your thumb.

        I like the second rule in perlref.
        Anywhere you'd put an identifier (or chain of identifiers) as part of a variable or subroutine name, you can replace the identifier with a BLOCK returning a reference of the correct type.

        Sure, the result is often ugly, but there are no exceptions or special cases. What more could my poor memory want.

        Bill
      I find the first one much harder to read. The difference between ( and { is subtle, but properly named variables ($handlers->{$event_name}->($event)) would make that irrelevant.