in reply to Correct idiom for default parameters

If you only have one layer of parameters (an HoV?), you could do this....

sub foo { my %defaults = ( a => 1, b => 2, c => 3, ); # other forms left as exercise... my %params = (%defaults, @_); # ... }

--MidLifeXis

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Re^2: Correct idiom for default parameters
by mrider (Beadle) on Apr 28, 2010 at 18:12 UTC

    Thanks for that, although that doesn't quite do what I'm hoping. I'm not necessarily looking for named parameters, and it makes calling the code more difficult than I wanted.

      It also makes the calling code self-documenting. This is a large win for anyone dealing with the code including you when you come back to it a couple months later and can't remember which of the 6 args goes in the middle or what happens if you leave arg 2 out, etc, etc.

        Maybe, maybe not. Sometimes, it's rather obvious what the arguments are. Sometimes, all the arguments play the same role. And sometimes, it would be just bloody annoying to use named parameters all the time. Do you really want to write:
        my $substr = substr(subject => $str, first_char => 5, length => 3, + replacement => "bar"); my @parts = split(subject => $str, pattern => qr/foo/, max_parts = +> 7, keep_trailing_empty_fields => 1);
        ? I'm not sure whether it's more readable. Or whether it's harder to remember that a negative third argument to split indicates trailing empty fields should be preserved than it is to remember the name of the flag.