error

Building dust-0.1.0.0...
Preprocessing executable 'dust' for dust-0.1.0.0...
Preprocessing test suite 'tests' for dust-0.1.0.0...
[2 of 4] Compiling Language.Parse   ( src/Language/Parse.hs, dist/build/tests/tests-tmp/Language/Parse.o )

src/Language/Parse.hs:17:12:
    No instance for (Stream s m Char) arising from a use of ‘oneOf’
    In a stmt of a 'do' block: first <- oneOf alpha
    In the expression:
      do { first <- oneOf alpha;
           rest <- many $ oneOf alphaNumericSymbol;
           return $ first : rest }
    In an equation for ‘expr’:
        expr
          = do { first <- oneOf alpha;
                 rest <- many $ oneOf alphaNumericSymbol;
                 return $ first : rest }

expr.hs

expr :: ParsecT s u m String
expr = do
  first <- oneOf alpha
  rest <- many $ oneOf alphaNumericSymbol
  return $ first : rest

-- charsets
numeric      = ['0'..'9']
alpha        = ['a'..'z'] ++ ['A'..'Z']
alphaNumeric = alpha ++ numeric
symbol = "'"

alphaNumericSymbol :: String
alphaNumericSymbol = alpha ++ numeric ++ symbol