NAME

TERN::it - Perl extension for easing nonautovivifying aggregate accesses

SYNOPSIS

            

              
              
use TERN::it;
it()
exists_it(\%$)
exists_itA(\@)
exists_itH(\%$)
defined_it(\$)
# instead of 
# print gen_printable $Data->{$state}->{$city}->{$lastname}->{$firstname}
#
exists_it %Data, $state and
exists_it %{it()}, $city and
exists_it %{it()}, $lastname and
exists_it %{it()}, $firstname and
print gen_printable it;
            
          

DESCRIPTION

            

              
              
 $TERN::it is a reserved variable that holds the object of the
 most recent C<exists> or <defined> operation.  The point of this
 is to allow descent into complex data structures without autovivifying
 the empty upper layers and also without repeating all the upper descent
 steps.  This is a small speed win.  This is how TERN will handle
 descent into compex, nested containers.
   
 C<it> this subroutine accesses the current value of it.
   
 C<exists_it> this subroutine takes two arguments, the first a hash
 and the second a key.  If we had prototype-based dispatch, there could
 be two versions be used with an array or a hash and Perl would figure out
 which to call but we don't.
   
 C<exists_itA> 
        exists_itA @fish, 7     # the same as exists $fish[7] but sets C<it>
         
 C<exists_itH>
        an alias to exists_it, for symmetry with exists_itA
         
 C<defined_it>
defined_it($something)  # the same as defined(${$TERN::it = \$something})
            
          

EXPORT

            

              
              
it
exists_it
exists_itA
exists_itH
defined_it
            
          

AUTHOR

David Nicol, <lt>davidnico@cpan.org<gt>

SEE ALSO

TERN.