extmod/modure: If input string is bytes, return bytes results too.

This applies to match.group() and split().

For ARM Thumb2, this increased code size by 12 bytes.

extmod/modure.c

@@ -31,6 +31,7 @@
 #include "py/nlr.h"
 #include "py/runtime.h"
 #include "py/binary.h"
+#include "py/objstr.h"
 
 #if MICROPY_PY_URE
 
@@ -69,7 +70,8 @@ STATIC mp_obj_t match_group(mp_obj_t self_in, mp_obj_t no_in) {
         // no match for this group
         return mp_const_none;
     }
-    return mp_obj_new_str(start, self->caps[no * 2 + 1] - start, false);
+    return mp_obj_new_str_of_type(mp_obj_get_type(self->str),
+        (const byte*)start, self->caps[no * 2 + 1] - start);
 }
 MP_DEFINE_CONST_FUN_OBJ_2(match_group_obj, match_group);
 
@@ -129,6 +131,7 @@ STATIC mp_obj_t re_split(size_t n_args, const mp_obj_t *args) {
     mp_obj_re_t *self = MP_OBJ_TO_PTR(args[0]);
     Subject subj;
     size_t len;
+    const mp_obj_type_t *str_type = mp_obj_get_type(args[1]);
     subj.begin = mp_obj_str_get_data(args[1], &len);
     subj.end = subj.begin + len;
     int caps_num = (self->re.sub + 1) * 2;
@@ -150,7 +153,7 @@ STATIC mp_obj_t re_split(size_t n_args, const mp_obj_t *args) {
             break;
         }
 
-        mp_obj_t s = mp_obj_new_str(subj.begin, caps[0] - subj.begin, false);
+        mp_obj_t s = mp_obj_new_str_of_type(str_type, (const byte*)subj.begin, caps[0] - subj.begin);
         mp_obj_list_append(retval, s);
         if (self->re.sub > 0) {
             mp_not_implemented("Splitting with sub-captures");
@@ -161,7 +164,7 @@ STATIC mp_obj_t re_split(size_t n_args, const mp_obj_t *args) {
         }
     }
 
-    mp_obj_t s = mp_obj_new_str(subj.begin, subj.end - subj.begin, false);
+    mp_obj_t s = mp_obj_new_str_of_type(str_type, (const byte*)subj.begin, subj.end - subj.begin);
     mp_obj_list_append(retval, s);
     return retval;
 }

tests/extmod/ure1.py

@@ -80,3 +80,6 @@
     re.compile("*")
 except:
     print("Caught invalid regex")
+
+# bytes objects
+m = re.match(rb'a+?', b'ab');  print(m.group(0))

tests/extmod/ure_split.py

@@ -26,3 +26,8 @@
 r = re.compile("[a-f]+")
 s = r.split("0a3b9")
 print(s)
+
+# bytes objects
+r = re.compile(b"x")
+s = r.split(b"fooxbar")
+print(s)