type check for ~d and ~D specifiers

2020-06-08 00:07:24 +02:00
parent 9bb851d437
commit c22816de08
1 changed files with 4 additions and 2 deletions
--- a/src/prolog/lib/format.pl
+++ b/src/prolog/lib/format.pl
@@ -172,9 +172,11 @@ cells([~,a|Fs], [Arg|Args], Tab, Es) --> !,
        { atom_chars(Arg, Chars) },
        cells(Fs, Args, Tab, [chars(Chars)|Es]).
 cells([~|Fs0], Args0, Tab, Es) -->
-        { numeric_argument(Fs0, Num, [d|Fs], Args0, [Arg|Args]) },
+        { numeric_argument(Fs0, Num, [d|Fs], Args0, [Arg0|Args]) },
        !,
-        { format_number_chars(Arg, Cs0) },
+        { Arg is Arg0, % evaluate compound expression
+          must_be(integer, Arg),
+          number_chars(Arg, Cs0) },
        (   { Num =:= 0 } -> { Cs = Cs0 }
        ;   { length(Cs0, L),
              (   L =< Num ->