isAllowedChar = flip (any . inRange)   [ ('\x21','\xD7FF') , ('\xE000','\xFFFD') , ('\x10000','\x10FFFD')  ]
             where i `inRange` (m,n) = m <= i && i <= n
isAllowedChar = flip (any . inRange)   [ ('\x21','\xD7FF') , ('\xE000','\xFFFD') , ('\x10000','\x10FFFD')  ]
             where i `inRange` (m,n) = m <= i && i <= n
isAllowedChar = flip (any . inRange)   [ ('\x21','\xD7FF') , ('\xE000','\xFFFD') , ('\x10000','\x10FFFD')  ]
             where i `inRange` (m,n) = m <= i && i <= n