$SOURCE='stuff.src';
$COMP='stuff.pm';

require $COMP;
*dostuff=\&Stuff::dostuff;

while (<>) {
  if (-M $SOURCE < -M $COMP) { # source changed?
    print "compiling...\n";
    system "cp $SOURCE $COMP"; # ok, fake compilation
    delete $INC{$COMP}; # make sure 'require' will load the module
    no warnings; # avoid some warnings
    require $COMP;
    *dostuff=\&Stuff::dostuff; # import
  }
  dostuff($_);
}