1 files changed, 51 insertions, 0 deletions
diff --git a/py/unicode.c b/py/unicode.c
index 88f835131d..a91e08078e 100644
--- a/py/unicode.c
+++ b/py/unicode.c
@@ -65,14 +65,65 @@ STATIC const uint8_t attr[] = {
     AT_LO, AT_LO, AT_LO, AT_PR, AT_PR, AT_PR, AT_PR, 0
 };
 
+// TODO: Rename to str_get_char
 unichar utf8_get_char(const byte *s) {
+#if MICROPY_PY_BUILTINS_STR_UNICODE
+    unichar ord = *s++;
+    if (!UTF8_IS_NONASCII(ord)) return ord;
+    ord &= 0x7F;
+    for (unichar mask = 0x40; ord & mask; mask >>= 1) {
+        ord &= ~mask;
+    }
+    while (UTF8_IS_CONT(*s)) {
+        ord = (ord << 6) | (*s++ & 0x3F);
+    }
+    return ord;
+#else
     return *s;
+#endif
 }
 
+// TODO: Rename to str_next_char
 const byte *utf8_next_char(const byte *s) {
+#if MICROPY_PY_BUILTINS_STR_UNICODE
+    ++s;
+    while (UTF8_IS_CONT(*s)) {
+        ++s;
+    }
+    return s;
+#else
     return s + 1;
+#endif
+}
+
+machine_uint_t utf8_ptr_to_index(const char *s, const char *ptr) {
+    machine_uint_t i = 0;
+    while (ptr > s) {
+        if (!UTF8_IS_CONT(*--ptr)) {
+            i++;
+        }
+    }
+
+    return i;
+}
+
+// TODO: Rename to str_charlen; return machine_uint_t
+uint unichar_charlen(const char *str, uint len)
+{
+#if MICROPY_PY_BUILTINS_STR_UNICODE
+    uint charlen = 0;
+    for (const char *top = str + len; str < top; ++str) {
+        if (!UTF8_IS_CONT(*str)) {
+            ++charlen;
+        }
+    }
+    return charlen;
+#else
+    return len;
+#endif
 }
 
+// Be aware: These unichar_is* functions are actually ASCII-only!
 bool unichar_isspace(unichar c) {
     return c < 128 && (attr[c] & FL_SPACE) != 0;
 }