function words(str) {
  var obj = {}, words = str.split(" ");
  for (var i = 0; i < words.length; ++i) obj[words[i]] = true;
  return obj;
}
var keywords = words(
  "absolute and array asm begin case const constructor destructor div do " +
    "downto else end file for function goto if implementation in inherited " +
    "inline interface label mod nil not object of operator or packed procedure " +
    "program record reintroduce repeat self set shl shr string then to type " +
    "unit until uses var while with xor as class dispinterface except exports " +
    "finalization finally initialization inline is library on out packed " +
    "property raise resourcestring threadvar try absolute abstract alias " +
    "assembler bitpacked break cdecl continue cppdecl cvar default deprecated " +
    "dynamic enumerator experimental export external far far16 forward generic " +
    "helper implements index interrupt iocheck local message name near " +
    "nodefault noreturn nostackframe oldfpccall otherwise overload override " +
    "pascal platform private protected public published read register " +
    "reintroduce result safecall saveregisters softfloat specialize static " +
    "stdcall stored strict unaligned unimplemented varargs virtual write");
var atoms = {"null": true};

var isOperatorChar = /[+\-*&%=<>!?|\/]/;

function tokenBase(stream, state) {
  var ch = stream.next();
  if (ch == "#" && state.startOfLine) {
    stream.skipToEnd();
    return "meta";
  }
  if (ch == '"' || ch == "'") {
    state.tokenize = tokenString(ch);
    return state.tokenize(stream, state);
  }
  if (ch == "(" && stream.eat("*")) {
    state.tokenize = tokenComment;
    return tokenComment(stream, state);
  }
  if (ch == "{") {
    state.tokenize = tokenCommentBraces;
    return tokenCommentBraces(stream, state);
  }
  if (/[\[\]\(\),;\:\.]/.test(ch)) {
    return null;
  }
  if (/\d/.test(ch)) {
    stream.eatWhile(/[\w\.]/);
    return "number";
  }
  if (ch == "/") {
    if (stream.eat("/")) {
      stream.skipToEnd();
      return "comment";
    }
  }
  if (isOperatorChar.test(ch)) {
    stream.eatWhile(isOperatorChar);
    return "operator";
  }
  stream.eatWhile(/[\w\$_]/);
  var cur = stream.current();
  if (keywords.propertyIsEnumerable(cur)) return "keyword";
  if (atoms.propertyIsEnumerable(cur)) return "atom";
  return "variable";
}

function tokenString(quote) {
  return function(stream, state) {
    var escaped = false, next, end = false;
    while ((next = stream.next()) != null) {
      if (next == quote && !escaped) {end = true; break;}
      escaped = !escaped && next == "\\";
    }
    if (end || !escaped) state.tokenize = null;
    return "string";
  };
}

function tokenComment(stream, state) {
  var maybeEnd = false, ch;
  while (ch = stream.next()) {
    if (ch == ")" && maybeEnd) {
      state.tokenize = null;
      break;
    }
    maybeEnd = (ch == "*");
  }
  return "comment";
}

function tokenCommentBraces(stream, state) {
  var ch;
  while (ch = stream.next()) {
    if (ch == "}") {
      state.tokenize = null;
      break;
    }
  }
  return "comment";
}

// Interface

const pascal = {
  startState: function() {
    return {tokenize: null};
  },

  token: function(stream, state) {
    if (stream.eatSpace()) return null;
    var style = (state.tokenize || tokenBase)(stream, state);
    if (style == "comment" || style == "meta") return style;
    return style;
  },

  languageData: {
    indentOnInput: /^\s*[{}]$/,
    commentTokens: {block: {open: "(*", close: "*)"}}
  }
};

export { pascal };
