Add character input/output

1 files changed, 52 insertions, 4 deletions

diff --git a/stdlib.pl b/stdlib.pl
index d31e3ab..0986781 100644
--- a/stdlib.pl
+++ b/stdlib.pl
@@ -217,10 +217,6 @@ write_canonical(Term) :-
 write_canonical(S, Term) :-
 	write_term(S, Term, [quoted(true), ignore_ops(true)]).
 
-nl :-
-	write_term('
-', []).
-
 % Arithmetic comparisons defined in terms of >=. This is not the most effective way,
 % but it is fine for now.
 
@@ -501,3 +497,55 @@ atom_concat(A1, A2, A3) :-
 	atom_codes(A2, Codes2).
 atom_concat(A1, A2, A3) :-
 	instantiation_error.
+
+% Character input/output
+
+get_char(Char) :-
+	current_input(S),
+	get_char(S, Char).
+
+get_code(Code) :-
+	current_input(S),
+	get_code(S, Code).
+
+get_code(S, Code) :-
+	get_char(S, Char),
+	( Char = end_of_file
+	-> Code = -1
+	; char_code(Char, Code)
+	).
+
+peek_char(Char) :-
+	current_input(S),
+	peek_char(S, Char).
+
+peek_code(Code) :-
+	current_input(S),
+	peek_code(S, Code).
+
+peek_code(S, Code) :-
+	peek_char(S, Char),
+	( Char = end_of_file
+	-> Code = -1
+	; char_code(Char, Code)
+	).
+
+put_char(Char) :-
+	current_output(S),
+	put_char(S, Char).
+
+put_code(Code) :-
+	current_output(S),
+	put_code(S, Code).
+
+put_code(S, Code) :-
+	char_code(Char, Code),
+	put_char(S, Char).
+
+nl :-
+	current_output(S),
+	nl(S).
+
+nl(S) :-
+	put_char(S, '
+'). % This should really be \n