use strict; 
my $evaled = 0; 
 
# very simplified... 
sub makesub { 
  my($name) = @_; 
  return "sub $name { print \"\$var \"; }"; 
} 
 
sub a { 
  my($var) = @_; 
  if(!$evaled) { 
    eval(makesub("somesub")); 
    $evaled=1; 
  } 
} 
 
a("what"); 
somesub(); 
a("the"); 
somesub(); 

##</code><code>##

sub a { 
  my($var) = @_; 
  if(!$evaled) { 
    eval(makesub("somesub")); 
    $evaled=1; 
  } 
  somesub();  # only place I call it from.
              # only want to eval once per
              # program execution, but have 
              # access to the my variables for
              # each calling of "a"
}