Fix parse_csv_file/2 to add comments/1 & comment/1 options

README.md

@@ -644,6 +644,8 @@ Where options can be:
 	trim(Boolean)				# default false, trims leading and trailing whitespace
 	numbers(Boolean)			# default false, converts integers and floats
 	header(Boolean)				# default false, skip first (header) line
+	comments(Boolean)			# default false, skip lines beginning with comment character
+	comment(Char)				# default '#', set the comment character
 	strings(Boolean)			# default depends on type of input (atom ot string)
 	assert(Boolean)				# default false, assertz to database instead (assumed for files, needs a functor)
 	functor(Atom)				# default output is a list, create a structure (mandatory for files and with assert)

src/predicates.c

@@ -7490,9 +7490,9 @@ static bool fn_parse_csv_file_2(query *q)
 	GET_FIRST_ARG(p1,atom);
 	GET_NEXT_ARG(p3,list_or_nil);
 	bool trim = false, numbers = false, use_strings = is_string(p1);
-	bool header = false, do_assert = true;
+	bool header = false, do_assert = true, comments = false;
 	const char *functor = NULL;
-	int sep = ',', quote = '"';
+	int sep = ',', quote = '"', comment = '#';
 	LIST_HANDLER(p3);
 
 	while (is_list(p3)) {
@@ -7506,6 +7506,8 @@ static bool fn_parse_csv_file_2(query *q)
 				trim = true;
 			else if (!strcmp("numbers", C_STR(q, h)) && is_atom(c) && (c->val_off == g_true_s))
 				numbers = true;
+			else if (!strcmp("comments", C_STR(q, h)) && is_atom(c) && (c->val_off == g_true_s))
+				comments = true;
 			else if (!strcmp("header", C_STR(q, h)) && is_atom(c) && (c->val_off == g_true_s))
 				header = true;
 			else if (!strcmp("strings", C_STR(q, h)) && is_atom(c) && (c->val_off == g_true_s))
@@ -7514,6 +7516,8 @@ static bool fn_parse_csv_file_2(query *q)
 				use_strings = false;
 			else if (!strcmp("functor", C_STR(q, h)) && is_atom(c))
 				functor = C_STR(q, c);
+			else if (!strcmp("comment", C_STR(q, h)) && is_atom(c) && (C_STRLEN_UTF8(c) == 1))
+				comment = peek_char_utf8(C_STR(q, c));
 			else if (!strcmp("sep", C_STR(q, h)) && is_atom(c) && (C_STRLEN_UTF8(c) == 1))
 				sep = peek_char_utf8(C_STR(q, c));
 			else if (!strcmp("quote", C_STR(q, h)) && is_atom(c) && (C_STRLEN_UTF8(c) == 1))
@@ -7538,6 +7542,7 @@ static bool fn_parse_csv_file_2(query *q)
 
 	while ((len = getline(&q->p->save_line, &q->p->n_line, q->p->fp)) != -1) {
 		char *line = q->p->save_line;
+		line_nbr++;
 
 		if (line[len-1] == '\n')
 			len--;
@@ -7552,13 +7557,14 @@ static bool fn_parse_csv_file_2(query *q)
 			continue;
 		}
 
+		if (comments && (line[0] == comment))
+			continue;
+
 		if (!do_parse_csv_line(q, sep, quote, trim, numbers, use_strings, functor, line, NULL, 0))
-			fprintf(stderr, "Error: line %u\n", line_nbr+1);
+			fprintf(stderr, "Error: line %u\n", line_nbr);
 
 		*f = save_f;
 		q->st.hp = save_hp;
-
-		line_nbr++;
 	}
 
 	free(q->p->save_line);