regex: don't print superfluous parens around classes.

* regex.c (print_rec): Switching from negative tests to
positive: print parens around elements of a compound which
have a lower precedence. The previously incorrectly omitted
set and cset remain unmentioned, so under this inversion of
logic, they print without parentheses.

1 files changed, 2 insertions, 2 deletions

diff --git a/regex.c b/regex.c
index 705ac26d..e61d29d3 100644
--- a/regex.c
+++ b/regex.c
@@ -2251,8 +2251,8 @@ static void print_rec(val exp, val stream, int *semi_flag)
     } else if (sym == compound_s) {
       for (; args; args = cdr(args)) {
         val arg = car(args);
-        if (consp(arg) && car(arg) != zeroplus_s && car(arg) != oneplus_s &&
-            car(arg) != optional_s && car (arg) != compound_s)
+        if (consp(arg) && (car(arg) == compl_s || car(arg) == and_s ||
+                           car(arg) == nongreedy_s))
           paren_print_rec(arg, stream, semi_flag);
         else
           print_rec(arg, stream, semi_flag);