in reply to Correct idiom for default parameters

This assumes 5.10 or higher:

sub defaults {
    my $self = shift;
    my $default1 = shift // 1;
    my $default2 = shift // 2;
    my $default3 = shift // 3;
    print("$default1 $default2 $default3\n");
}

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Though I would never claim this is the "correct" idiom. Celebrate TIMTOWTDI!

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Re^2: Correct idiom for default parameters
by mrider (Beadle) on Apr 28, 2010 at 17:41 UTC

    Ack! 5.8.8 here (sigh).

    Thanks for the suggestion though.

[reply]

      This is 5.8 accessible and might even be more palatable?

      Updated per LanX's correction below. 

      sub test{ 
    my( $p1, $p2, $p3) = map{ scalar @_ ? shift : $_ }( 1, 2, 3 ); 
    print "p1:$p1; p2:$p2; p3:$p3"; 
};;

test();;
p1:1; p2:2; p3:3

test( 'a' );;
p1:a; p2:2; p3:3

test( 'a', 'b', 'c' );;
p1:a; p2:b; p3:c

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      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.
[reply]
[d/l]
        careful!

        passing undef in between will break your idiom.

        IMHO better check scalar @_ or care explicitly about passing undef !

        sub defaults { 
    my( $p1, $p2, $p3) = map{ defined $_[0] ? shift : $_ }( 1, 2, 3 );
+ 
    print "p1:$p1; p2:$p2; p3:$p3\n"; 
}; 
 
defaults(undef, 0, 0);

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        Cheers Rolf

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