text: CodeMirror.defineMode("haskell", function() {
  
    function switchState(source, setState, f) {
      setState(f);
      return f(source, setState);
    }
    
    // These should all be Unicode extended, as per the Haskell 2010 report
    var smallRE = /[a-z_]/;
    var largeRE = /[A-Z]/;
    var digitRE = /[0-9]/;
    var hexitRE = /[0-9A-Fa-f]/;
    var octitRE = /[0-7]/;
    var idRE = /[a-z_A-Z0-9']/;
    var symbolRE = /[-!#$%&*+.\/<=>?@\\^|~:]/;
    var specialRE = /[(),;[\]`{}]/;
    var whiteCharRE = /[ \t\v\f]/; // newlines are handled in tokenizer
      
    function normal(source, setState) {
      if (source.eatWhile(whiteCharRE)) {
        return null;
      }
        
      var ch = source.next();
      if (specialRE.test(ch)) {
        if (ch == '{' && source.eat('-')) {
          var t = "comment";
          if (source.eat('#')) {
            t = "meta";
          }
          return switchState(source, setState, ncomment(t, 1));
        }
        return null;
      }
      
      if (ch == '\'') {
        if (source.eat('\\')) {
          source.next();  // should handle other escapes here
        }
        else {
          source.next();
        }
        if (source.eat('\'')) {
          return "string";
        }
        return "error";
      }
      
      if (ch == '"') {
        return switchState(source, setState, stringLiteral);
      }
        
      if (largeRE.test(ch)) {
        source.eatWhile(idRE);
        if (source.eat('.')) {
          return "qualifier";
        }
        return "variable-2";
      }
        
      if (smallRE.test(ch)) {
        source.eatWhile(idRE);
        return "variable";
      }
        
      if (digitRE.test(ch)) {
        if (ch == '0') {
          if (source.eat(/[xX]/)) {
            source.eatWhile(hexitRE); // should require at least 1
            return "integer";
          }
          if (source.eat(/[oO]/)) {
            source.eatWhile(octitRE); // should require at least 1
            return "number";
          }
        }
        source.eatWhile(digitRE);
        var t = "number";
        if (source.eat('.')) {
          t = "number";
          source.eatWhile(digitRE); // should require at least 1
        }
        if (source.eat(/[eE]/)) {
          t = "number";
          source.eat(/[-+]/);
          source.eatWhile(digitRE); // should require at least 1
        }
        return t;
      }
        
      if (symbolRE.test(ch)) {
        if (ch == '-' && source.eat(/-/)) {
          source.eatWhile(/-/);
          if (!source.eat(symbolRE)) {
            source.skipToEnd();
            return "comment";
          }
        }
        var t = "variable";
        if (ch == ':') {
          t = "variable-2";
        }
        source.eatWhile(symbolRE);
        return t;    
      }
        
      return "error";
    }
      
    function ncomment(type, nest) {
      if (nest == 0) {
        return normal;
      }
      return function(source, setState) {
        var currNest = nest;
        while (!source.eol()) {
          var ch = source.next();
          if (ch == '{' && source.eat('-')) {
            ++currNest;
          }
          else if (ch == '-' && source.eat('}')) {
            --currNest;
            if (currNest == 0) {
              setState(normal);
              return type;
            }
          }
        }
        setState(ncomment(type, currNest));
        return type;
      };
    }
      
    function stringLiteral(source, setState) {
      while (!source.eol()) {
        var ch = source.next();
        if (ch == '"') {
          setState(normal);
          return "string";
        }
        if (ch == '\\') {
          if (source.eol() || source.eat(whiteCharRE)) {
            setState(stringGap);
            return "string";
          }
          if (source.eat('&')) {
          }
          else {
            source.next(); // should handle other escapes here
          }
        }
      }
      setState(normal);
      return "error";
    }
    
    function stringGap(source, setState) {
      if (source.eat('\\')) {
        return switchState(source, setState, stringLiteral);
      }
      source.next();
      setState(normal);
      return "error";
    }
    
    
    var wellKnownWords = (function() {
      var wkw = {};
      function setType(t) {
        return function () {
          for (var i = 0; i < arguments.length; i++)
            wkw[arguments[i]] = t;
        };
      }
      
      setType("keyword")(
        "case", "class", "data", "default", "deriving", "do", "else", "foreign",
        "if", "import", "in", "infix", "infixl", "infixr", "instance", "let",
        "module", "newtype", "of", "then", "type", "where", "_");
        
      setType("keyword")(
        "\.\.", ":", "::", "=", "\\", "\"", "<-", "->", "@", "~", "=>");
        
      setType("builtin")(
        "!!", "$!", "$", "&&", "+", "++", "-", ".", "/", "/=", "<", "<=", "=<<",
        "==", ">", ">=", ">>", ">>=", "^", "^^", "||", "*", "**");
        
      setType("builtin")(
        "Bool", "Bounded", "Char", "Double", "EQ", "Either", "Enum", "Eq",
        "False", "FilePath", "Float", "Floating", "Fractional", "Functor", "GT",
        "IO", "IOError", "Int", "Integer", "Integral", "Just", "LT", "Left",
        "Maybe", "Monad", "Nothing", "Num", "Ord", "Ordering", "Rational", "Read",
        "ReadS", "Real", "RealFloat", "RealFrac", "Right", "Show", "ShowS",
        "String", "True");
        
      setType("builtin")(
        "abs", "acos", "acosh", "all", "and", "any", "appendFile", "asTypeOf",
        "asin", "asinh", "atan", "atan2", "atanh", "break", "catch", "ceiling",
        "compare", "concat", "concatMap", "const", "cos", "cosh", "curry",
        "cycle", "decodeFloat", "div", "divMod", "drop", "dropWhile", "either",
        "elem", "encodeFloat", "enumFrom", "enumFromThen", "enumFromThenTo",
        "enumFromTo", "error", "even", "exp", "exponent", "fail", "filter",
        "flip", "floatDigits", "floatRadix", "floatRange", "floor", "fmap",
        "foldl", "foldl1", "foldr", "foldr1", "fromEnum", "fromInteger",
        "fromIntegral", "fromRational", "fst", "gcd", "getChar", "getContents",
        "getLine", "head", "id", "init", "interact", "ioError", "isDenormalized",
        "isIEEE", "isInfinite", "isNaN", "isNegativeZero", "iterate", "last",
        "lcm", "length", "lex", "lines", "log", "logBase", "lookup", "map",
        "mapM", "mapM_", "max", "maxBound", "maximum", "maybe", "min", "minBound",
        "minimum", "mod", "negate", "not", "notElem", "null", "odd", "or",
        "otherwise", "pi", "pred", "print", "product", "properFraction",
        "putChar", "putStr", "putStrLn", "quot", "quotRem", "read", "readFile",
        "readIO", "readList", "readLn", "readParen", "reads", "readsPrec",
        "realToFrac", "recip", "rem", "repeat", "replicate", "return", "reverse",
        "round", "scaleFloat", "scanl", "scanl1", "scanr", "scanr1", "seq",
        "sequence", "sequence_", "show", "showChar", "showList", "showParen",
        "showString", "shows", "showsPrec", "significand", "signum", "sin",
        "sinh", "snd", "span", "splitAt", "sqrt", "subtract", "succ", "sum",
        "tail", "take", "takeWhile", "tan", "tanh", "toEnum", "toInteger",
        "toRational", "truncate", "uncurry", "undefined", "unlines", "until",
        "unwords", "unzip", "unzip3", "userError", "words", "writeFile", "zip",
        "zip3", "zipWith", "zipWith3");
        
      return wkw;
    })();
      
    
    
    return {
      startState: function ()  { return { f: normal }; },
      copyState:  function (s) { return { f: s.f }; },
      
      token: function(stream, state) {
        var t = state.f(stream, function(s) { state.f = s; });
        var w = stream.current();
        return (w in wellKnownWords) ? wellKnownWords[w] : t;
      }
    };
  
  });
  
  CodeMirror.defineMIME("text/x-haskell", "haskell");
  