Data.Char repeated readLitChar barfs on output from show "ó1"
"ó1" is "\243\&1" and when shown that's "\"\\243\\&1\""
readLitChar "\"\\243\\&1\"" = [('"', "\\243\\&1\"")]
readLitChar "\\243\\&1\"" = [('\243', "\\&1\"")] --should have consumed "\\&"
readLitChar "\\&1\"" = []