int
TclUniCharToUCS4(
    const Tcl_UniChar *src,	/* The Tcl_UniChar string. */
    int *ucs4Ptr)	/* Filled with the UCS4 codepoint represented
			 * by the Tcl_UniChar string. */
{
    if (((src[0] & 0xFC00) == 0xD800) && ((src[1] & 0xFC00) == 0xDC00)) {
	*ucs4Ptr = (((src[0] & 0x3FF) << 10) | (src[1] & 0x3FF)) + 0x10000;
	return 2;
    }
    *ucs4Ptr = src[0];
    return 1;
}

const Tcl_UniChar *TclUCS4Prev(const Tcl_UniChar *src, const Tcl_UniChar *ptr) {
    if (src <= ptr + 1) {
    	return ptr;
    }
    if (((src[-1] & 0xFC00) == 0xDC00) && ((src[-2] & 0xFC00) == 0xD800)) {
	return src - 2;
    }
    return src - 1;
}



#endif

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78