in reply to Correct idiom for default parameters

Here's one way (requires 5.10+). You'll decide for yourself if it is any better: 

sub test{ 
    my $p1 = shift // 1; 
    my $p2 = shift // 2; 
    my $p3 = shift // 3; 
    print "p1:$p1; p2:$p2; p3:$p3";
};;

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

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

test( 'a', 'b' );;
p1:a; p2:b; 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.
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Re^2: Correct idiom for default parameters
by Anonymous Monk on Apr 29, 2010 at 07:41 UTC

    What about the more obvious following?

    sub test{ 
    my $p1 = shift || 1; 
    [...]

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[d/l]

      Suffers because you cannot set $p1 explicitly to 0 (or '' or undef). That's why 5.10 has //.

      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.
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