Implicit parameter aliases

[Dave Whipp]

Are parameter names part of the function signature? A6 defines "siglets",
which don't appear to include parameter names.

If I write:

  sub foo( Int $a, Int $b ) {...}
  sub foo( Int $a, Int $c ) { print $a+$c }

Are these now equivalent:

  foo( a => 1, b => 2 )
  foo( a => 1, c => 3 )

What if I wrote:

  sub bar( Int $a, Num $b ) {...}
  sub bar( Int $b, Num $a ) { print $a - $b }
  bar( a => 1, b => 3 )

Hopefully this is an error!

Can I discriminate on parameter names using multi subs?

  multi sub alu( $num, $add is required_named) { print $num + $add}
  multi sub alu( $num, $sub is required_named) { print $num - $sub }

  alu( 5, add=>4 ); # prints "9"
  alu( 5, sub=>4 ); # prints "1"

Dave.