in reply to Examples fo Where "our" is really needed

I seek some example to meditate upon in which the "our" syntax really helps improve the performance or readability of the code. Pray tell me what those examples might be!

Two (small) advantages for me.

First it allows me to type less and still have clarity. For example I prefer this

our $VERSION = '1.00';

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to this

use vars qw( $VERSION );
....
$VERSION = '1.00';

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or this

$SomePackage::VERSION = '1.00';

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Secondly I like being able to localise access to scary things like globals to just where I need them so I can do things like this:

sub AUTOLOAD {
    our $AUTOLOAD;
    ....
};

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I admit these are small advantages, and some would say too small to drop backward compatability, but I like them and will quite happily continue to use our :-)

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Re^2: Examples fo Where "our" is really needed
by ihb (Deacon) on May 05, 2005 at 14:50 UTC

    I prefer 

    $VERSION = '1.00';

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    over any of your alternatives above. Now you might wonder how I handle strict. Fact is I don't. I don't have stricture enabled until I have done the assignment to $VERSION and other globals I don't plan to type again.

    being able to localise access to scary things like globals to just where I need them

    Just a clarification. I've seen people declare the same variable twice but one should not do 

    sub foo {
  our $foo;
  ...
}
sub bar { ... }
sub baz {
  our $foo;   # BAD!
  ...
}

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    to avoid access to $foo inside &bar. Use some other scope trick for that if it's needed. One misses a great point of having the declaration if one does it more than once for the same variable.

    ihb

    See perltoc if you don't know which perldoc to read!

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      The whole point of the word "our" in English is that it indicates shared property, and more than one person us allowed to say it about the same object without an argument breaking out. In Perl the word "our" does not declare a variable, but a private view of a public variable. It is quite properly limited to the lexical scope that uses the view. Sure, you can throw two functions into the one artificial lexical (or class) scope to share one "our" declaration, but that's a trick that doesn't scale well to multiply intersected sharings. Even Fortran got that one right.
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        In Perl the word "our" does not declare a variable, but a private view of a public variable.

        That's why I said "declare the same variable twice" and meant exactly the same as you do but with different words. Regardless how one choose to paint the issue I don't like to do the same thing twice if I don't have to or have a good reason not to. If I can't use regular ways of scoping access to a global then I can't, but if I can, as in my example above, I really prefer to not repeat myself. The day I refactor my code and/or mistype the name in one "repeated" our I might very well be hunting reasons for my uninitialized warnings instead of getting the help from the compiler I could've gotten. I'm unfortunately not just hypothesizing.

        our has its uses, but I think that scattering out ours to tighten down the access scope for globals instead of create new scopes when that's possible/not inconvenient is an abuse rather than a use of our.

        ihb

        See perltoc if you don't know which perldoc to read!

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      Fact is I don't. I don't have stricture enabled until I have done the assignment to $VERSION and other globals I don't plan to type again.

      Fair enough. I just can't be bothered to spend my limited brain power wondering about which globals I'll just use once, or bother spending time switching between methods if I change my mind later - so I just use our pretty much all of the time :-)

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