Expanded vtable for methods to determine whether a combinator is ok to use with regular or CF grammars.

src/parsers/and.c

@@ -11,6 +11,11 @@ static HParseResult *parse_and(void* env, HParseState* state) {
 
 static const HParserVtable and_vt = {
   .parse = parse_and,
+  .isValidRegular = h_false, /* TODO: strictly speaking this should be regular,
+				but it will be a huge amount of work and difficult
+				to get right, so we're leaving it for a future
+				revision. --mlp, 18/12/12 */
+  .isValidCF = h_false,      /* despite TODO above, this remains false. */
 };