#if TCL_UTF_MAX > 4
    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
#else /* Tcl_UtfCharComplete() might point to 2nd byte of valid 4-byte sequence */
    3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
    3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
#endif
    2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
    2,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
    3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
#if TCL_UTF_MAX > 4
    4,4,4,4,4,
#else
    3,3,3,3,3, /* Tcl_UtfCharComplete() only checks TCL_UTF_MAX bytes */
#endif
    1,1,1,1,1,1,1,1,1,1,1

int
Tcl_NumUtfChars(
    register const char *src,	/* The UTF-8 string to measure. */
    int length)			/* The length of the string in bytes, or -1
				 * for strlen(string). */
{
    Tcl_UniChar ch = 0;
    register int i = 0;

    int i = 0;
 
    /*
     * The separate implementations are faster.
     *
     * Since this is a time-sensitive function, we also do the check for the
     * single-byte char case specially.
     */

    if (length < 0) {
	while ((*src != '\0') && (i < INT_MAX)) {
	    src = TclUtfNext(src);
	    src += Tcl_UtfToUniChar(src, &ch);
	    i++;
	}
	if (i < 0) i = INT_MAX; /* Bug [2738427] */
    } else {
	register const char *endPtr = src + length - TCL_UTF_MAX;
	const char *endPtr = src + length - TCL_UTF_MAX;

	while (src < endPtr) {
	    src = TclUtfNext(src);
	    src += Tcl_UtfToUniChar(src, &ch);
	    i++;
	}
	endPtr += TCL_UTF_MAX;
	while ((src < endPtr) && Tcl_UtfCharComplete(src, endPtr - src)) {
	    src = TclUtfNext(src);
	    src += Tcl_UtfToUniChar(src, &ch);
	    i++;
	}
	if (src < endPtr) {
	    i += endPtr - src;
	}
    }
    return i;

 */

const char *
Tcl_UtfAtIndex(
    register const char *src,	/* The UTF-8 string. */
    register int index)		/* The position of the desired character. */
{
#if 0
#if 1
/* The Tcl 8.6 implementation */
    Tcl_UniChar ch = 0;
    int len = 0;

    while (index-- > 0) {
	len = TclUtfToUniChar(src, &ch);
	src += len;