sub my_func{
  my ( $self, $ptr_array, $value ) = @_;
  return look_right() if ( $value == 0 );
  return look_left() if ( $value == @{ $ptr_array } );
  return ( look_right() && look_left() );

  sub look_right() {... [uses $value and $ptr_array] }
  sub look_left()  {... [uses $value and $ptr_array] }
}