strengthen type check

2024-03-18 21:35:12 +01:00
parent 1db6bff890
commit 8af29c200d
1 changed files with 1 additions and 1 deletions
--- a/src/lib/format.pl
+++ b/src/lib/format.pl
@@ -88,7 +88,7 @@ format_(Fs, Args) -->
        format_cells(Cells).

 format_args_cells(Fs, Args, Cells) :-
-        must_be(list, Fs),
+        must_be(chars, Fs),
        must_be(list, Args),
        unique_variable_names(Args, VNs),
        phrase(cells(Fs,Args,0,[],VNs), Cells).