function unicode_reverse(string utf8)
sequence utf32 = utf8_to_utf32(utf8)
integer ch
    -- the assumption is made that <char><comb1><comb2>
    -- and <char><comb2><comb1> etc would work the same.
    for i=1 to length(utf32) do
        ch = utf32[i]
        if (ch>=0x300 and ch<=0x36f)
        or (ch>=0x1dc0 and ch<=0x1dff)
        or (ch>=0x20d0 and ch<=0x20ff)
        or (ch>=0xfe20 and ch<=0xfe2f) then
            utf32[i] = utf32[i-1]
            utf32[i-1] = ch
        end if
    end for
    utf32 = reverse(utf32)
    utf8 = utf32_to_utf8(utf32)
    return utf8
end function