sub create_index {
   my ($dbh, $index_name, $frontend, $backend, $scoring) = @_;

   . . .
}

. . .

my $index = create_index($dbh, 'search_index', 'string', 'phrase', 1);

##</code><code>##

sub create_index {
   my %args = @_;
  
   # retrieve/use subroutine parameters from the
   # %args hash!

   . . .
}

. . .

my $index = create_index(
                         dbh => $dbh,
                         index_name => 'search_index',
                         frontend => 'string',
                         backend => 'phrase'
                         scoring => 1
                         );