/* GPL(C) Mohsin Ahmed, http://www.cs.albany.edu/~mosh
 * SYNOPSIS: pretty print a prolog list.
 */

listcopy(In,Out):-
	see(In),
	tell(Out),
	repeat,
		read(X),
		process(X),
		X=end_of_file,
		seen,
		told.

process(end_of_file) :- !.
process(X):-
	pph(0,X),
	 write('.').

ppt(_,[]).

ppt(N,[H|T]):-
	write(','),nl,pph(N,H),
	ppt(N,T).

pph(N,[H|T]):-
	 M is N+5,
	 spaces(N),
	 write('['),nl,
	 pph(M,H),
	 ppt(M,T),nl,
	 spaces(M),
	 write(']').

pph(N,H):-
	atomic(H),
	spaces(N),
	write(H).

spaces(0).
spaces(N):-
	 N>0,
	 write(' '),
	 M is N-1,
	 spaces(M).