py/modbuiltins: Share vstr_add_char's implementation of utf8 encoding.
This saves ~84 bytes on trinket m0, and saves 112 bytes on PYBV10.
Signed-off-by: Jeff Epler <jepler@gmail.com>
diff --git a/py/modbuiltins.c b/py/modbuiltins.c
index da29e5b..4ff7d44 100644
--- a/py/modbuiltins.c
+++ b/py/modbuiltins.c
@@ -137,30 +137,12 @@
STATIC mp_obj_t mp_builtin_chr(mp_obj_t o_in) {
#if MICROPY_PY_BUILTINS_STR_UNICODE
mp_uint_t c = mp_obj_get_int(o_in);
- uint8_t str[4];
- int len = 0;
- if (c < 0x80) {
- *str = c;
- len = 1;
- } else if (c < 0x800) {
- str[0] = (c >> 6) | 0xC0;
- str[1] = (c & 0x3F) | 0x80;
- len = 2;
- } else if (c < 0x10000) {
- str[0] = (c >> 12) | 0xE0;
- str[1] = ((c >> 6) & 0x3F) | 0x80;
- str[2] = (c & 0x3F) | 0x80;
- len = 3;
- } else if (c < 0x110000) {
- str[0] = (c >> 18) | 0xF0;
- str[1] = ((c >> 12) & 0x3F) | 0x80;
- str[2] = ((c >> 6) & 0x3F) | 0x80;
- str[3] = (c & 0x3F) | 0x80;
- len = 4;
- } else {
+ if (c >= 0x110000) {
mp_raise_ValueError(MP_ERROR_TEXT("chr() arg not in range(0x110000)"));
}
- return mp_obj_new_str_via_qstr((char *)str, len);
+ VSTR_FIXED(buf, 4);
+ vstr_add_char(&buf, c);
+ return mp_obj_new_str_via_qstr(buf.buf, buf.len);
#else
mp_int_t ord = mp_obj_get_int(o_in);
if (0 <= ord && ord <= 0xff) {