Hello, It may be e little bit a strange question, but I am trying to understand some code. The problem is that in this code two subs are calling each other. How is this possible, or am I interpreting things the wrong way. In the following code the  my $retval = $self->{'timespan'}->init({%{$li}}) is calling sub init, but this sub init is calling sub process again. Here is the necessary code to understand my question:

# for parse modules, sub init is sort of int.main() function
sub init
{
 my ( $self, $input ) = @_ ;
 $self->{'_input_'}->{'_type_'} = 'process';
 my $li = $self->update_user_input( $input );
 $self->process($li,$input)
}

# True process module, calls methods from Request::Request_Help.
sub process
{
 # The incoming array is split into $self, $li and $input
 my ($self, $li, $input) = @_ ;
 # $li is a hash-reference where the keys preforid, order_by and order
+_sequence are designated
 # the values 1, time and ASC respectively.
 $li->{preforid} = 1;
 $li->{order_by} = "time";
 $li->{order_sequence} = "ASC";
 my $retval = $self->{'timespan'}->init({%{$li}});
 my %stanet;
 if ($retval) {
 foreach my $sta (@$retval)
  {
   # Check if sufficient data is already in database [bud_reader]; if 
+not, process station.
   $li->{station}     = $sta->{sta};
   $li->{starttime}   = $sta->{starttime};
   $li->{endtime}     = $sta->{endtime};
   my $is_data   = $self->{'bud_reader'}->init($li);
[download]

Hope anyone knows?