/dev/null) or exploit the counting properties. The initial encoding of Stream is
utf8, enabling arbitrary Unicode output. The encoding can be changed to determine byte counts of the output in a particular encoding or validate if output is possible in a particular encoding. For example, the code below determines the number of characters emitted when writing Term.
write_length(Term, Len) :- open_null_stream(Out), write(Out, Term), character_count(Out, Len0), close(Out), Len = Len0.