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in reply to Schwartzian Transform as a module?

Take this example from the Cookbook (page 120) 
print map { $_->[0] }
      sort {
          $a->[1] <=> $b->[1]
                   ||
          $a->[2] <=> $b->[2]
                   ||
          $a->[3] cmp $b->[3]
      }
      map { [ $_, (split /:/)[3, 2, 0] ] }
      qx(cat /etc/passwd);
How do you modularize a multi-criterion sort? Of course, it can be done, but the resulting module invocation would be more cumbersome and less readable than an inline Schwartzian transform.

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Re: Re: Schwartzian Transform as a module?
by I0 (Priest) on Oct 02, 2002 at 06:18 UTC 
    sub ST(&@){
        my $metric=shift;
        map {$_->[0]}
        sort {$a->[1] cmp $b->[1]}
        map {[$_,&{$metric}]} @_
}
print ST{sprintf"%9d%9d%s",(split/:/)[3,2,0]} qx(cat /etc/passwd);

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