Re^2: Correct idiom for default parameters

more condensed:

sub defaults {
  my ($d1,$d2,$d3) = map { @_ ? shift : $_ } (1,2,3);
  print("$d1 $d2 $d3\n");
}
 
defaults();
defaults(0);
defaults(0, 0);
defaults(0, 0, 0);
[download]

plz note: this solution depends on the number of defaulted parameters...

Cheers Rolf

Comment on Re^2: Correct idiom for default parameters Download Code

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Re^3: Correct idiom for default parameters by mrider (Beadle) on Apr 28, 2010 at 22:52 UTC
That looks pretty good! And to answer your question in the post previous to this one, no I don't expect there to be an "undef" in the middle. The overwhelming majority of the cases there is one parameter that is optional. Which means that the predominant use will look like this: `sub defaults { my ($self, $param) = map { @_ ? shift : $_ } (1); print($param); }` [download] I found one place where it would be nice to have two optional parameters, but I'm debating refactoring that sub routine.	[reply] [d/l]
Re^4: Correct idiom for default parameters by LanX (Saint) on Apr 28, 2010 at 22:58 UTC
> `my ($self, $param) = map { @_ ? shift : $_ } (1);` ehm ... $self defaults to 1??? ;-) IMHO better catch $self in a separate shift! UPDATE: > The overwhelming majority of the cases there is one parameter that is optional. Which means that the predominant use will look like this: Then better avoid this construct! IMHO it's much clearer (and faster) to write `my ($self,$a,$b,$c,$d)=@_; $d = 4 unless defined $d;` [download] Cheers Rolf	[reply] [d/l] [select]