Operating on pairs, Was Re: Revised solution #2

[Richard Hainsworth]

Larry Wall wrote:
On Wed, Jan 14, 2009 at 09:55:38AM +0300, Richard Hainsworth wrote:
  
However, I came across one thing in solution #3 that I posted yesterday.  
$pair.fmt("%s %s") is nice, but it doesnt allow for any action on either  
value or key before printing (I wanted to print the value as a  
percentage), and this had to be done in a printf statement. In fact the  
printf statement was the longest and ugliest statement in the program.
    

Maybe I'm missing something, but you can always do:

    $pair.key.foo.fmt("%s"),
    $pair.value.bar.fmt("%s")

Larry
  
This surely requires that foo and bar are defined as sub's.

Suppose I just need a single transformation of a value before outputting 
it? Eg., expressing .value as a percentage of $count?

Is there some way to include a one-off in the subroutine "chain"? 
Something like
$pair.value.{shift / 10}.fmt("%s");