package parser;

...
# Some constructor here
...

#set values -- this part works
sub parse{
   ...
   $self->{var1} = 'a';
   $self->{var2} = 'b';
   $self->{var3} = 'c';
   ...
}

sub get_var{
   my ($self, $var_name) = @_;
   return $self->{$var_name};
}