DB<112> sub tst2 { 'a' =~ /(\w)/; $1. tst(). $1 }
 => 0
 
  DB<113> sub tst { 'b' =~ /(\w)/; $1}
 => 0
 
  DB<114> 'c' =~ /(\w)/; print $1. tst2(). $1
 => 1
cabac