I disagree. I prefer passing named arguments as a hash reference:

    sub Open {
        my( $file, $opts )= @_;
        foreach $key (  %$opts  ) {
            # ...
        }
    }

    Open( "file", { ReadOnly=>1, Retries=>2 } );
[download]

for the following reasons:

• It leaves lots of room for flexability in the API. For example, if my routine requires a 'file' parameter, then I don't see much point in requiring you to type File => when I can do things as above. You can even have optional parameters:

      sub Open {
          my $opts= UNIVERSAL::isa( $_[-1], "HASH" )
              ? pop(@_) : {};
          my( $file, $mode, $mask )= @_;
          # ...
      }
  
      Open( "file" );
      Open( "file", { Exclusive=> 1 } );
      Open( "file", "w", 0666, { Locked=>1 } );
  [download]

• The "Odd number of elements in hash assignment" warning automatically gets thrown at the calling code where it belongs
• It provides a visual cue that named arguments are being used
• It stops you from getting tricky and doing:     Create( Name=>"This", Users=>'fred','bob','joe' ); which you will regret later. Instead you are forced to:     Create( Name=>"This", Users=>['fred','bob','joe'] );

But you need to be careful to not have your function modify the hash. (:

        - tye