Add observatory_pub_packages snapshot to third_party

observatory_pub_packages/html5lib/src/tokenizer.dart

+library tokenizer;
+
+import 'dart:collection';
+import 'package:html5lib/parser.dart' show HtmlParser;
+import 'constants.dart';
+import 'inputstream.dart';
+import 'token.dart';
+import 'utils.dart';
+
+// Group entities by their first character, for faster lookups
+
+// TODO(jmesserly): we could use a better data structure here like a trie, if
+// we had it implemented in Dart.
+Map<String, List<String>> entitiesByFirstChar = (() {
+  var result = {};
+  for (var k in entities.keys) {
+    result.putIfAbsent(k[0], () => []).add(k);
+  }
+  return result;
+})();
+
+// TODO(jmesserly): lots of ways to make this faster:
+// - use char codes everywhere instead of 1-char strings
+// - use switch instead of contains, indexOf
+// - use switch instead of the sequential if tests
+// - avoid string concat
+
+/// This class takes care of tokenizing HTML.
+class HtmlTokenizer implements Iterator<Token> {
+  // TODO(jmesserly): a lot of these could be made private
+
+  final HtmlInputStream stream;
+
+  final bool lowercaseElementName;
+
+  final bool lowercaseAttrName;
+
+  /// True to generate spans in for [Token.span].
+  final bool generateSpans;
+
+  /// True to generate spans for attributes.
+  final bool attributeSpans;
+
+  /// This reference to the parser is used for correct CDATA handling.
+  /// The [HtmlParser] will set this at construction time.
+  HtmlParser parser;
+
+  final Queue<Token> tokenQueue;
+
+  /// Holds the token that is currently being processed.
+  Token currentToken;
+
+  /// Holds a reference to the method to be invoked for the next parser state.
+  // TODO(jmesserly): the type should be "Predicate" but a dart2js checked mode
+  // bug prevents us from doing that. See http://dartbug.com/12465
+  Function state;
+
+  String temporaryBuffer;
+
+  int _lastOffset;
+
+  // TODO(jmesserly): ideally this would be a LinkedHashMap and we wouldn't add
+  // an item until it's ready. But the code doesn't have a clear notion of when
+  // it's "done" with the attribute.
+  List<TagAttribute> _attributes;
+  Set<String> _attributeNames;
+
+  HtmlTokenizer(doc, {String encoding, bool parseMeta: true,
+      this.lowercaseElementName: true, this.lowercaseAttrName: true,
+      bool generateSpans: false, String sourceUrl, this.attributeSpans: false})
+      : stream = new HtmlInputStream(
+            doc, encoding, parseMeta, generateSpans, sourceUrl),
+        tokenQueue = new Queue(),
+        generateSpans = generateSpans {
+    reset();
+  }
+
+  TagToken get currentTagToken => currentToken;
+  DoctypeToken get currentDoctypeToken => currentToken;
+  StringToken get currentStringToken => currentToken;
+
+  Token _current;
+  Token get current => _current;
+
+  String get _attributeName => _attributes.last.name;
+  set _attributeName(String value) {
+    _attributes.last.name = value;
+  }
+
+  String get _attributeValue => _attributes.last.value;
+  set _attributeValue(String value) {
+    _attributes.last.value = value;
+  }
+
+  void _markAttributeEnd(int offset) {
+    if (attributeSpans) _attributes.last.end = stream.position + offset;
+  }
+
+  void _markAttributeValueStart(int offset) {
+    if (attributeSpans) _attributes.last.startValue = stream.position + offset;
+  }
+
+  void _markAttributeValueEnd(int offset) {
+    if (attributeSpans) {
+      _attributes.last.endValue = stream.position + offset;
+      _markAttributeEnd(offset);
+    }
+  }
+
+  // Note: we could track the name span here, if we need it.
+  void _markAttributeNameEnd(int offset) => _markAttributeEnd(offset);
+
+  void _addAttribute(String name) {
+    if (_attributes == null) _attributes = [];
+    var attr = new TagAttribute(name);
+    _attributes.add(attr);
+    if (attributeSpans) attr.start = stream.position - name.length;
+  }
+
+  /// This is where the magic happens.
+  ///
+  /// We do our usually processing through the states and when we have a token
+  /// to return we yield the token which pauses processing until the next token
+  /// is requested.
+  bool moveNext() {
+    // Start processing. When EOF is reached state will return false;
+    // instead of true and the loop will terminate.
+    while (stream.errors.length == 0 && tokenQueue.length == 0) {
+      if (!state()) {
+        _current = null;
+        return false;
+      }
+    }
+    if (stream.errors.length > 0) {
+      _current = new ParseErrorToken(stream.errors.removeFirst());
+    } else {
+      assert (tokenQueue.length > 0);
+      _current = tokenQueue.removeFirst();
+    }
+    return true;
+  }
+
+  /// Resets the tokenizer state. Calling this does not reset the [stream] or
+  /// the [parser].
+  void reset() {
+    _lastOffset = 0;
+    tokenQueue.clear();
+    currentToken = null;
+    temporaryBuffer = null;
+    _attributes = null;
+    _attributeNames = null;
+    state = dataState;
+  }
+
+  /// Adds a token to the queue. Sets the span if needed.
+  void _addToken(Token token) {
+    if (generateSpans && token.span == null) {
+      int offset = stream.position;
+      token.span = stream.fileInfo.span(_lastOffset, offset);
+      if (token is! ParseErrorToken) {
+        _lastOffset = offset;
+      }
+    }
+    tokenQueue.add(token);
+  }
+
+  /// This function returns either U+FFFD or the character based on the
+  /// decimal or hexadecimal representation. It also discards ";" if present.
+  /// If not present it will add a [ParseErrorToken].
+  String consumeNumberEntity(bool isHex) {
+    var allowed = isDigit;
+    var radix = 10;
+    if (isHex) {
+      allowed = isHexDigit;
+      radix = 16;
+    }
+
+    var charStack = [];
+
+    // Consume all the characters that are in range while making sure we
+    // don't hit an EOF.
+    var c = stream.char();
+    while (allowed(c) && c != EOF) {
+      charStack.add(c);
+      c = stream.char();
+    }
+
+    // Convert the set of characters consumed to an int.
+    var charAsInt = parseIntRadix(charStack.join(), radix);
+
+    // Certain characters get replaced with others
+    var char = replacementCharacters[charAsInt];
+    if (char != null) {
+      _addToken(new ParseErrorToken(
+          "illegal-codepoint-for-numeric-entity",
+          messageParams: {"charAsInt": charAsInt}));
+    } else if ((0xD800 <= charAsInt && charAsInt <= 0xDFFF)
+        || (charAsInt > 0x10FFFF)) {
+      char = "\uFFFD";
+      _addToken(new ParseErrorToken(
+          "illegal-codepoint-for-numeric-entity",
+          messageParams: {"charAsInt": charAsInt}));
+    } else {
+      // Should speed up this check somehow (e.g. move the set to a constant)
+      if ((0x0001 <= charAsInt && charAsInt <= 0x0008) ||
+          (0x000E <= charAsInt && charAsInt <= 0x001F) ||
+          (0x007F <= charAsInt && charAsInt <= 0x009F) ||
+          (0xFDD0 <= charAsInt && charAsInt <= 0xFDEF) ||
+          const [0x000B, 0xFFFE, 0xFFFF, 0x1FFFE,
+                0x1FFFF, 0x2FFFE, 0x2FFFF, 0x3FFFE,
+                0x3FFFF, 0x4FFFE, 0x4FFFF, 0x5FFFE,
+                0x5FFFF, 0x6FFFE, 0x6FFFF, 0x7FFFE,
+                0x7FFFF, 0x8FFFE, 0x8FFFF, 0x9FFFE,
+                0x9FFFF, 0xAFFFE, 0xAFFFF, 0xBFFFE,
+                0xBFFFF, 0xCFFFE, 0xCFFFF, 0xDFFFE,
+                0xDFFFF, 0xEFFFE, 0xEFFFF, 0xFFFFE,
+                0xFFFFF, 0x10FFFE, 0x10FFFF].contains(charAsInt)) {
+        _addToken(new ParseErrorToken(
+            "illegal-codepoint-for-numeric-entity",
+            messageParams: {"charAsInt": charAsInt}));
+      }
+      char = new String.fromCharCodes([charAsInt]);
+    }
+
+    // Discard the ; if present. Otherwise, put it back on the queue and
+    // invoke parseError on parser.
+    if (c != ";") {
+      _addToken(new ParseErrorToken(
+          "numeric-entity-without-semicolon"));
+      stream.unget(c);
+    }
+    return char;
+  }
+
+  void consumeEntity({String allowedChar, bool fromAttribute: false}) {
+    // Initialise to the default output for when no entity is matched
+    var output = "&";
+
+    var charStack = [stream.char()];
+    if (isWhitespace(charStack[0]) || charStack[0] == '<' || charStack[0] == '&'
+        || charStack[0] == EOF || allowedChar == charStack[0]) {
+      stream.unget(charStack[0]);
+    } else if (charStack[0] == "#") {
+      // Read the next character to see if it's hex or decimal
+      bool hex = false;
+      charStack.add(stream.char());
+      if (charStack.last == 'x' || charStack.last == 'X') {
+        hex = true;
+        charStack.add(stream.char());
+      }
+
+      // charStack.last should be the first digit
+      if (hex && isHexDigit(charStack.last) ||
+          (!hex && isDigit(charStack.last))) {
+        // At least one digit found, so consume the whole number
+        stream.unget(charStack.last);
+        output = consumeNumberEntity(hex);
+      } else {
+        // No digits found
+        _addToken(new ParseErrorToken("expected-numeric-entity"));
+        stream.unget(charStack.removeLast());
+        output = "&${charStack.join()}";
+      }
+    } else {
+      // At this point in the process might have named entity. Entities
+      // are stored in the global variable "entities".
+      //
+      // Consume characters and compare to these to a substring of the
+      // entity names in the list until the substring no longer matches.
+      var filteredEntityList = entitiesByFirstChar[charStack[0]];
+      if (filteredEntityList == null) filteredEntityList = const [];
+
+      while (charStack.last != EOF) {
+        var name = charStack.join();
+        filteredEntityList = filteredEntityList.where(
+            (e) => e.startsWith(name)).toList();
+
+        if (filteredEntityList.length == 0) {
+          break;
+        }
+        charStack.add(stream.char());
+      }
+
+      // At this point we have a string that starts with some characters
+      // that may match an entity
+      String entityName = null;
+
+      // Try to find the longest entity the string will match to take care
+      // of &noti for instance.
+
+      int entityLen;
+      for (entityLen = charStack.length - 1; entityLen > 1; entityLen--) {
+        var possibleEntityName = charStack.sublist(0, entityLen).join();
+        if (entities.containsKey(possibleEntityName)) {
+          entityName = possibleEntityName;
+          break;
+        }
+      }
+
+      if (entityName != null) {
+        var lastChar = entityName[entityName.length - 1];
+        if (lastChar != ";") {
+          _addToken(new ParseErrorToken(
+              "named-entity-without-semicolon"));
+        }
+        if (lastChar != ";" && fromAttribute &&
+            (isLetterOrDigit(charStack[entityLen]) ||
+             charStack[entityLen] == '=')) {
+          stream.unget(charStack.removeLast());
+          output = "&${charStack.join()}";
+        } else {
+          output = entities[entityName];
+          stream.unget(charStack.removeLast());
+          output = '${output}${slice(charStack, entityLen).join()}';
+        }
+      } else {
+        _addToken(new ParseErrorToken("expected-named-entity"));
+        stream.unget(charStack.removeLast());
+        output = "&${charStack.join()}";
+      }
+    }
+    if (fromAttribute) {
+      _attributeValue = '$_attributeValue$output';
+    } else {
+      var token;
+      if (isWhitespace(output)) {
+        token = new SpaceCharactersToken(output);
+      } else {
+        token = new CharactersToken(output);
+      }
+      _addToken(token);
+    }
+  }
+
+  /// This method replaces the need for "entityInAttributeValueState".
+  void processEntityInAttribute(String allowedChar) {
+    consumeEntity(allowedChar: allowedChar, fromAttribute: true);
+  }
+
+  /// This method is a generic handler for emitting the tags. It also sets
+  /// the state to "data" because that's what's needed after a token has been
+  /// emitted.
+  void emitCurrentToken() {
+    var token = currentToken;
+    // Add token to the queue to be yielded
+    if (token is TagToken) {
+      if (lowercaseElementName) {
+        token.name = asciiUpper2Lower(token.name);
+      }
+      if (token is EndTagToken) {
+        if (_attributes != null) {
+          _addToken(new ParseErrorToken("attributes-in-end-tag"));
+        }
+        if (token.selfClosing) {
+          _addToken(new ParseErrorToken("this-closing-flag-on-end-tag"));
+        }
+      } else if (token is StartTagToken) {
+        // HTML5 specific normalizations to the token stream.
+        // Convert the list into a map where first key wins.
+        token.data = new LinkedHashMap<Object, String>();
+        if (_attributes != null) {
+          for (var attr in _attributes) {
+            token.data.putIfAbsent(attr.name, () => attr.value);
+          }
+          if (attributeSpans) token.attributeSpans = _attributes;
+        }
+      }
+      _attributes = null;
+      _attributeNames = null;
+    }
+    _addToken(token);
+    state = dataState;
+  }
+
+  // Below are the various tokenizer states worked out.
+
+  bool dataState() {
+    var data = stream.char();
+    if (data == "&") {
+      state = entityDataState;
+    } else if (data == "<") {
+      state = tagOpenState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      _addToken(new CharactersToken("\u0000"));
+    } else if (data == EOF) {
+      // Tokenization ends.
+      return false;
+    } else if (isWhitespace(data)) {
+      // Directly after emitting a token you switch back to the "data
+      // state". At that point spaceCharacters are important so they are
+      // emitted separately.
+      _addToken(new SpaceCharactersToken(
+          '${data}${stream.charsUntil(spaceCharacters, true)}'));
+      // No need to update lastFourChars here, since the first space will
+      // have already been appended to lastFourChars and will have broken
+      // any <!-- or --> sequences
+    } else {
+      var chars = stream.charsUntil("&<\u0000");
+      _addToken(new CharactersToken('${data}${chars}'));
+    }
+    return true;
+  }
+
+  bool entityDataState() {
+    consumeEntity();
+    state = dataState;
+    return true;
+  }
+
+  bool rcdataState() {
+    var data = stream.char();
+    if (data == "&") {
+      state = characterReferenceInRcdata;
+    } else if (data == "<") {
+      state = rcdataLessThanSignState;
+    } else if (data == EOF) {
+      // Tokenization ends.
+      return false;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      _addToken(new CharactersToken("\uFFFD"));
+    } else if (isWhitespace(data)) {
+      // Directly after emitting a token you switch back to the "data
+      // state". At that point spaceCharacters are important so they are
+      // emitted separately.
+      _addToken(new SpaceCharactersToken(
+          '${data}${stream.charsUntil(spaceCharacters, true)}'));
+    } else {
+      var chars = stream.charsUntil("&<");
+      _addToken(new CharactersToken('${data}${chars}'));
+    }
+    return true;
+  }
+
+  bool characterReferenceInRcdata() {
+    consumeEntity();
+    state = rcdataState;
+    return true;
+  }
+
+  bool rawtextState() {
+    var data = stream.char();
+    if (data == "<") {
+      state = rawtextLessThanSignState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      _addToken(new CharactersToken("\uFFFD"));
+    } else if (data == EOF) {
+      // Tokenization ends.
+      return false;
+    } else {
+      var chars = stream.charsUntil("<\u0000");
+      _addToken(new CharactersToken("${data}${chars}"));
+    }
+    return true;
+  }
+
+  bool scriptDataState() {
+    var data = stream.char();
+    if (data == "<") {
+      state = scriptDataLessThanSignState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      _addToken(new CharactersToken("\uFFFD"));
+    } else if (data == EOF) {
+      // Tokenization ends.
+      return false;
+    } else {
+      var chars = stream.charsUntil("<\u0000");
+      _addToken(new CharactersToken("${data}${chars}"));
+    }
+    return true;
+  }
+
+  bool plaintextState() {
+    var data = stream.char();
+    if (data == EOF) {
+      // Tokenization ends.
+      return false;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      _addToken(new CharactersToken("\uFFFD"));
+    } else {
+      _addToken(new CharactersToken(
+          '${data}${stream.charsUntil("\u0000")}'));
+    }
+    return true;
+  }
+
+  bool tagOpenState() {
+    var data = stream.char();
+    if (data == "!") {
+      state = markupDeclarationOpenState;
+    } else if (data == "/") {
+      state = closeTagOpenState;
+    } else if (isLetter(data)) {
+      currentToken = new StartTagToken(data);
+      state = tagNameState;
+    } else if (data == ">") {
+      // XXX In theory it could be something besides a tag name. But
+      // do we really care?
+      _addToken(new ParseErrorToken(
+          "expected-tag-name-but-got-right-bracket"));
+      _addToken(new CharactersToken("<>"));
+      state = dataState;
+    } else if (data == "?") {
+      // XXX In theory it could be something besides a tag name. But
+      // do we really care?
+      _addToken(new ParseErrorToken(
+          "expected-tag-name-but-got-question-mark"));
+      stream.unget(data);
+      state = bogusCommentState;
+    } else {
+      // XXX
+      _addToken(new ParseErrorToken("expected-tag-name"));
+      _addToken(new CharactersToken("<"));
+      stream.unget(data);
+      state = dataState;
+    }
+    return true;
+  }
+
+  bool closeTagOpenState() {
+    var data = stream.char();
+    if (isLetter(data)) {
+      currentToken = new EndTagToken(data);
+      state = tagNameState;
+    } else if (data == ">") {
+      _addToken(new ParseErrorToken(
+          "expected-closing-tag-but-got-right-bracket"));
+      state = dataState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken(
+          "expected-closing-tag-but-got-eof"));
+      _addToken(new CharactersToken("</"));
+      state = dataState;
+    } else {
+      // XXX data can be _'_...
+      _addToken(new ParseErrorToken(
+          "expected-closing-tag-but-got-char", messageParams: {"data": data}));
+      stream.unget(data);
+      state = bogusCommentState;
+    }
+    return true;
+  }
+
+  bool tagNameState() {
+    var data = stream.char();
+    if (isWhitespace(data)) {
+      state = beforeAttributeNameState;
+    } else if (data == ">") {
+      emitCurrentToken();
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-tag-name"));
+      state = dataState;
+    } else if (data == "/") {
+      state = selfClosingStartTagState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      currentTagToken.name = '${currentTagToken.name}\uFFFD';
+    } else {
+      currentTagToken.name = '${currentTagToken.name}$data';
+      // (Don't use charsUntil here, because tag names are
+      // very short and it's faster to not do anything fancy)
+    }
+    return true;
+  }
+
+  bool rcdataLessThanSignState() {
+    var data = stream.char();
+    if (data == "/") {
+      temporaryBuffer = "";
+      state = rcdataEndTagOpenState;
+    } else {
+      _addToken(new CharactersToken("<"));
+      stream.unget(data);
+      state = rcdataState;
+    }
+    return true;
+  }
+
+  bool rcdataEndTagOpenState() {
+    var data = stream.char();
+    if (isLetter(data)) {
+      temporaryBuffer = '${temporaryBuffer}$data';
+      state = rcdataEndTagNameState;
+    } else {
+      _addToken(new CharactersToken("</"));
+      stream.unget(data);
+      state = rcdataState;
+    }
+    return true;
+  }
+
+  bool _tokenIsAppropriate() {
+    return currentToken is TagToken &&
+        currentTagToken.name.toLowerCase() == temporaryBuffer.toLowerCase();
+  }
+
+  bool rcdataEndTagNameState() {
+    var appropriate = _tokenIsAppropriate();
+    var data = stream.char();
+    if (isWhitespace(data) && appropriate) {
+      currentToken = new EndTagToken(temporaryBuffer);
+      state = beforeAttributeNameState;
+    } else if (data == "/" && appropriate) {
+      currentToken = new EndTagToken(temporaryBuffer);
+      state = selfClosingStartTagState;
+    } else if (data == ">" && appropriate) {
+      currentToken = new EndTagToken(temporaryBuffer);
+      emitCurrentToken();
+      state = dataState;
+    } else if (isLetter(data)) {
+      temporaryBuffer = '${temporaryBuffer}$data';
+    } else {
+      _addToken(new CharactersToken("</$temporaryBuffer"));
+      stream.unget(data);
+      state = rcdataState;
+    }
+    return true;
+  }
+
+  bool rawtextLessThanSignState() {
+    var data = stream.char();
+    if (data == "/") {
+      temporaryBuffer = "";
+      state = rawtextEndTagOpenState;
+    } else {
+      _addToken(new CharactersToken("<"));
+      stream.unget(data);
+      state = rawtextState;
+    }
+    return true;
+  }
+
+  bool rawtextEndTagOpenState() {
+    var data = stream.char();
+    if (isLetter(data)) {
+      temporaryBuffer = '${temporaryBuffer}$data';
+      state = rawtextEndTagNameState;
+    } else {
+      _addToken(new CharactersToken("</"));
+      stream.unget(data);
+      state = rawtextState;
+    }
+    return true;
+  }
+
+  bool rawtextEndTagNameState() {
+    var appropriate = _tokenIsAppropriate();
+    var data = stream.char();
+    if (isWhitespace(data) && appropriate) {
+      currentToken = new EndTagToken(temporaryBuffer);
+      state = beforeAttributeNameState;
+    } else if (data == "/" && appropriate) {
+      currentToken = new EndTagToken(temporaryBuffer);
+      state = selfClosingStartTagState;
+    } else if (data == ">" && appropriate) {
+      currentToken = new EndTagToken(temporaryBuffer);
+      emitCurrentToken();
+      state = dataState;
+    } else if (isLetter(data)) {
+      temporaryBuffer = '${temporaryBuffer}$data';
+    } else {
+      _addToken(new CharactersToken("</$temporaryBuffer"));
+      stream.unget(data);
+      state = rawtextState;
+    }
+    return true;
+  }
+
+  bool scriptDataLessThanSignState() {
+    var data = stream.char();
+    if (data == "/") {
+      temporaryBuffer = "";
+      state = scriptDataEndTagOpenState;
+    } else if (data == "!") {
+      _addToken(new CharactersToken("<!"));
+      state = scriptDataEscapeStartState;
+    } else {
+      _addToken(new CharactersToken("<"));
+      stream.unget(data);
+      state = scriptDataState;
+    }
+    return true;
+  }
+
+  bool scriptDataEndTagOpenState() {
+    var data = stream.char();
+    if (isLetter(data)) {
+      temporaryBuffer = '${temporaryBuffer}$data';
+      state = scriptDataEndTagNameState;
+    } else {
+      _addToken(new CharactersToken("</"));
+      stream.unget(data);
+      state = scriptDataState;
+    }
+    return true;
+  }
+
+  bool scriptDataEndTagNameState() {
+    var appropriate = _tokenIsAppropriate();
+    var data = stream.char();
+    if (isWhitespace(data) && appropriate) {
+      currentToken = new EndTagToken(temporaryBuffer);
+      state = beforeAttributeNameState;
+    } else if (data == "/" && appropriate) {
+      currentToken = new EndTagToken(temporaryBuffer);
+      state = selfClosingStartTagState;
+    } else if (data == ">" && appropriate) {
+      currentToken = new EndTagToken(temporaryBuffer);
+      emitCurrentToken();
+      state = dataState;
+    } else if (isLetter(data)) {
+      temporaryBuffer = '${temporaryBuffer}$data';
+    } else {
+      _addToken(new CharactersToken("</$temporaryBuffer"));
+      stream.unget(data);
+      state = scriptDataState;
+    }
+    return true;
+  }
+
+  bool scriptDataEscapeStartState() {
+    var data = stream.char();
+    if (data == "-") {
+      _addToken(new CharactersToken("-"));
+      state = scriptDataEscapeStartDashState;
+    } else {
+      stream.unget(data);
+      state = scriptDataState;
+    }
+    return true;
+  }
+
+  bool scriptDataEscapeStartDashState() {
+    var data = stream.char();
+    if (data == "-") {
+      _addToken(new CharactersToken("-"));
+      state = scriptDataEscapedDashDashState;
+    } else {
+      stream.unget(data);
+      state = scriptDataState;
+    }
+    return true;
+  }
+
+  bool scriptDataEscapedState() {
+    var data = stream.char();
+    if (data == "-") {
+      _addToken(new CharactersToken("-"));
+      state = scriptDataEscapedDashState;
+    } else if (data == "<") {
+      state = scriptDataEscapedLessThanSignState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      _addToken(new CharactersToken("\uFFFD"));
+    } else if (data == EOF) {
+      state = dataState;
+    } else {
+      var chars = stream.charsUntil("<-\u0000");
+      _addToken(new CharactersToken("${data}${chars}"));
+    }
+    return true;
+  }
+
+  bool scriptDataEscapedDashState() {
+    var data = stream.char();
+    if (data == "-") {
+      _addToken(new CharactersToken("-"));
+      state = scriptDataEscapedDashDashState;
+    } else if (data == "<") {
+      state = scriptDataEscapedLessThanSignState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      _addToken(new CharactersToken("\uFFFD"));
+      state = scriptDataEscapedState;
+    } else if (data == EOF) {
+      state = dataState;
+    } else {
+      _addToken(new CharactersToken(data));
+      state = scriptDataEscapedState;
+    }
+    return true;
+  }
+
+  bool scriptDataEscapedDashDashState() {
+    var data = stream.char();
+    if (data == "-") {
+      _addToken(new CharactersToken("-"));
+    } else if (data == "<") {
+      state = scriptDataEscapedLessThanSignState;
+    } else if (data == ">") {
+      _addToken(new CharactersToken(">"));
+      state = scriptDataState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      _addToken(new CharactersToken("\uFFFD"));
+      state = scriptDataEscapedState;
+    } else if (data == EOF) {
+      state = dataState;
+    } else {
+      _addToken(new CharactersToken(data));
+      state = scriptDataEscapedState;
+    }
+    return true;
+  }
+
+  bool scriptDataEscapedLessThanSignState() {
+    var data = stream.char();
+    if (data == "/") {
+      temporaryBuffer = "";
+      state = scriptDataEscapedEndTagOpenState;
+    } else if (isLetter(data)) {
+      _addToken(new CharactersToken("<$data"));
+      temporaryBuffer = data;
+      state = scriptDataDoubleEscapeStartState;
+    } else {
+      _addToken(new CharactersToken("<"));
+      stream.unget(data);
+      state = scriptDataEscapedState;
+    }
+    return true;
+  }
+
+  bool scriptDataEscapedEndTagOpenState() {
+    var data = stream.char();
+    if (isLetter(data)) {
+      temporaryBuffer = data;
+      state = scriptDataEscapedEndTagNameState;
+    } else {
+      _addToken(new CharactersToken("</"));
+      stream.unget(data);
+      state = scriptDataEscapedState;
+    }
+    return true;
+  }
+
+  bool scriptDataEscapedEndTagNameState() {
+    var appropriate = _tokenIsAppropriate();
+    var data = stream.char();
+    if (isWhitespace(data) && appropriate) {
+      currentToken = new EndTagToken(temporaryBuffer);
+      state = beforeAttributeNameState;
+    } else if (data == "/" && appropriate) {
+      currentToken = new EndTagToken(temporaryBuffer);
+      state = selfClosingStartTagState;
+    } else if (data == ">" && appropriate) {
+      currentToken = new EndTagToken(temporaryBuffer);
+      emitCurrentToken();
+      state = dataState;
+    } else if (isLetter(data)) {
+      temporaryBuffer = '${temporaryBuffer}$data';
+    } else {
+      _addToken(new CharactersToken("</$temporaryBuffer"));
+      stream.unget(data);
+      state = scriptDataEscapedState;
+    }
+    return true;
+  }
+
+  bool scriptDataDoubleEscapeStartState() {
+    var data = stream.char();
+    if (isWhitespace(data) || data == "/" || data == ">") {
+      _addToken(new CharactersToken(data));
+      if (temporaryBuffer.toLowerCase() == "script") {
+        state = scriptDataDoubleEscapedState;
+      } else {
+        state = scriptDataEscapedState;
+      }
+    } else if (isLetter(data)) {
+      _addToken(new CharactersToken(data));
+      temporaryBuffer = '${temporaryBuffer}$data';
+    } else {
+      stream.unget(data);
+      state = scriptDataEscapedState;
+    }
+    return true;
+  }
+
+  bool scriptDataDoubleEscapedState() {
+    var data = stream.char();
+    if (data == "-") {
+      _addToken(new CharactersToken("-"));
+      state = scriptDataDoubleEscapedDashState;
+    } else if (data == "<") {
+      _addToken(new CharactersToken("<"));
+      state = scriptDataDoubleEscapedLessThanSignState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      _addToken(new CharactersToken("\uFFFD"));
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-script-in-script"));
+      state = dataState;
+    } else {
+      _addToken(new CharactersToken(data));
+    }
+    return true;
+  }
+
+  bool scriptDataDoubleEscapedDashState() {
+    var data = stream.char();
+    if (data == "-") {
+      _addToken(new CharactersToken("-"));
+      state = scriptDataDoubleEscapedDashDashState;
+    } else if (data == "<") {
+      _addToken(new CharactersToken("<"));
+      state = scriptDataDoubleEscapedLessThanSignState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      _addToken(new CharactersToken("\uFFFD"));
+      state = scriptDataDoubleEscapedState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-script-in-script"));
+      state = dataState;
+    } else {
+      _addToken(new CharactersToken(data));
+      state = scriptDataDoubleEscapedState;
+    }
+    return true;
+  }
+
+  // TODO(jmesserly): report bug in original code
+  // (was "Dash" instead of "DashDash")
+  bool scriptDataDoubleEscapedDashDashState() {
+    var data = stream.char();
+    if (data == "-") {
+      _addToken(new CharactersToken("-"));
+    } else if (data == "<") {
+      _addToken(new CharactersToken("<"));
+      state = scriptDataDoubleEscapedLessThanSignState;
+    } else if (data == ">") {
+      _addToken(new CharactersToken(">"));
+      state = scriptDataState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      _addToken(new CharactersToken("\uFFFD"));
+      state = scriptDataDoubleEscapedState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-script-in-script"));
+      state = dataState;
+    } else {
+      _addToken(new CharactersToken(data));
+      state = scriptDataDoubleEscapedState;
+    }
+    return true;
+  }
+
+  bool scriptDataDoubleEscapedLessThanSignState() {
+    var data = stream.char();
+    if (data == "/") {
+      _addToken(new CharactersToken("/"));
+      temporaryBuffer = "";
+      state = scriptDataDoubleEscapeEndState;
+    } else {
+      stream.unget(data);
+      state = scriptDataDoubleEscapedState;
+    }
+    return true;
+  }
+
+  bool scriptDataDoubleEscapeEndState() {
+    var data = stream.char();
+    if (isWhitespace(data) || data == "/" || data == ">") {
+      _addToken(new CharactersToken(data));
+      if (temporaryBuffer.toLowerCase() == "script") {
+        state = scriptDataEscapedState;
+      } else {
+        state = scriptDataDoubleEscapedState;
+      }
+    } else if (isLetter(data)) {
+      _addToken(new CharactersToken(data));
+      temporaryBuffer = '${temporaryBuffer}$data';
+    } else {
+      stream.unget(data);
+      state = scriptDataDoubleEscapedState;
+    }
+    return true;
+  }
+
+  bool beforeAttributeNameState() {
+    var data = stream.char();
+    if (isWhitespace(data)) {
+      stream.charsUntil(spaceCharacters, true);
+    } else if (isLetter(data)) {
+      _addAttribute(data);
+      state = attributeNameState;
+    } else if (data == ">") {
+      emitCurrentToken();
+    } else if (data == "/") {
+      state = selfClosingStartTagState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("expected-attribute-name-but-got-eof"));
+      state = dataState;
+    } else if ("'\"=<".contains(data)) {
+      _addToken(new ParseErrorToken("invalid-character-in-attribute-name"));
+      _addAttribute(data);
+      state = attributeNameState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      _addAttribute("\uFFFD");
+      state = attributeNameState;
+    } else {
+      _addAttribute(data);
+      state = attributeNameState;
+    }
+    return true;
+  }
+
+  bool attributeNameState() {
+    var data = stream.char();
+    bool leavingThisState = true;
+    bool emitToken = false;
+    if (data == "=") {
+      state = beforeAttributeValueState;
+    } else if (isLetter(data)) {
+      _attributeName = '$_attributeName$data'
+          '${stream.charsUntil(asciiLetters, true)}';
+      leavingThisState = false;
+    } else if (data == ">") {
+      // XXX If we emit here the attributes are converted to a dict
+      // without being checked and when the code below runs we error
+      // because data is a dict not a list
+      emitToken = true;
+    } else if (isWhitespace(data)) {
+      state = afterAttributeNameState;
+    } else if (data == "/") {
+      state = selfClosingStartTagState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      _attributeName = '${_attributeName}\uFFFD';
+      leavingThisState = false;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-attribute-name"));
+      state = dataState;
+    } else if ("'\"<".contains(data)) {
+      _addToken(new ParseErrorToken("invalid-character-in-attribute-name"));
+      _attributeName = '$_attributeName$data';
+      leavingThisState = false;
+    } else {
+      _attributeName = '$_attributeName$data';
+      leavingThisState = false;
+    }
+
+    if (leavingThisState) {
+      _markAttributeNameEnd(-1);
+
+      // Attributes are not dropped at this stage. That happens when the
+      // start tag token is emitted so values can still be safely appended
+      // to attributes, but we do want to report the parse error in time.
+      if (lowercaseAttrName) {
+        _attributeName = asciiUpper2Lower(_attributeName);
+      }
+      if (_attributeNames == null) _attributeNames = new Set();
+      if (_attributeNames.contains(_attributeName)) {
+        _addToken(new ParseErrorToken("duplicate-attribute"));
+      }
+      _attributeNames.add(_attributeName);
+
+      // XXX Fix for above XXX
+      if (emitToken) {
+        emitCurrentToken();
+      }
+    }
+    return true;
+  }
+
+  bool afterAttributeNameState() {
+    var data = stream.char();
+    if (isWhitespace(data)) {
+      stream.charsUntil(spaceCharacters, true);
+    } else if (data == "=") {
+      state = beforeAttributeValueState;
+    } else if (data == ">") {
+      emitCurrentToken();
+    } else if (isLetter(data)) {
+      _addAttribute(data);
+      state = attributeNameState;
+    } else if (data == "/") {
+      state = selfClosingStartTagState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      _addAttribute("\uFFFD");
+      state = attributeNameState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("expected-end-of-tag-but-got-eof"));
+      state = dataState;
+    } else if ("'\"<".contains(data)) {
+      _addToken(new ParseErrorToken("invalid-character-after-attribute-name"));
+      _addAttribute(data);
+      state = attributeNameState;
+    } else {
+      _addAttribute(data);
+      state = attributeNameState;
+    }
+    return true;
+  }
+
+  bool beforeAttributeValueState() {
+    var data = stream.char();
+    if (isWhitespace(data)) {
+      stream.charsUntil(spaceCharacters, true);
+    } else if (data == "\"") {
+      _markAttributeValueStart(0);
+      state = attributeValueDoubleQuotedState;
+    } else if (data == "&") {
+      state = attributeValueUnQuotedState;
+      stream.unget(data);
+      _markAttributeValueStart(0);
+    } else if (data == "'") {
+      _markAttributeValueStart(0);
+      state = attributeValueSingleQuotedState;
+    } else if (data == ">") {
+      _addToken(new ParseErrorToken(
+          "expected-attribute-value-but-got-right-bracket"));
+      emitCurrentToken();
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      _markAttributeValueStart(-1);
+      _attributeValue = '${_attributeValue}\uFFFD';
+      state = attributeValueUnQuotedState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("expected-attribute-value-but-got-eof"));
+      state = dataState;
+    } else if ("=<`".contains(data)) {
+      _addToken(new ParseErrorToken("equals-in-unquoted-attribute-value"));
+      _markAttributeValueStart(-1);
+      _attributeValue = '$_attributeValue$data';
+      state = attributeValueUnQuotedState;
+    } else {
+      _markAttributeValueStart(-1);
+      _attributeValue = '$_attributeValue$data';
+      state = attributeValueUnQuotedState;
+    }
+    return true;
+  }
+
+  bool attributeValueDoubleQuotedState() {
+    var data = stream.char();
+    if (data == "\"") {
+      _markAttributeValueEnd(-1);
+      _markAttributeEnd(0);
+      state = afterAttributeValueState;
+    } else if (data == "&") {
+      processEntityInAttribute('"');
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      _attributeValue = '${_attributeValue}\uFFFD';
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-attribute-value-double-quote"));
+      _markAttributeValueEnd(-1);
+      state = dataState;
+    } else {
+      _attributeValue = '$_attributeValue$data${stream.charsUntil("\"&")}';
+    }
+    return true;
+  }
+
+  bool attributeValueSingleQuotedState() {
+    var data = stream.char();
+    if (data == "'") {
+      _markAttributeValueEnd(-1);
+      _markAttributeEnd(0);
+      state = afterAttributeValueState;
+    } else if (data == "&") {
+      processEntityInAttribute("'");
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      _attributeValue = '${_attributeValue}\uFFFD';
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-attribute-value-single-quote"));
+      _markAttributeValueEnd(-1);
+      state = dataState;
+    } else {
+      _attributeValue = '$_attributeValue$data${stream.charsUntil("\'&")}';
+    }
+    return true;
+  }
+
+  bool attributeValueUnQuotedState() {
+    var data = stream.char();
+    if (isWhitespace(data)) {
+      _markAttributeValueEnd(-1);
+      state = beforeAttributeNameState;
+    } else if (data == "&") {
+      processEntityInAttribute(">");
+    } else if (data == ">") {
+      _markAttributeValueEnd(-1);
+      emitCurrentToken();
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-attribute-value-no-quotes"));
+      _markAttributeValueEnd(-1);
+      state = dataState;
+    } else if ('"\'=<`'.contains(data)) {
+      _addToken(new ParseErrorToken(
+          "unexpected-character-in-unquoted-attribute-value"));
+      _attributeValue = '$_attributeValue$data';
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      _attributeValue = '${_attributeValue}\uFFFD';
+    } else {
+      _attributeValue = '$_attributeValue$data'
+          '${stream.charsUntil("&>\"\'=<`$spaceCharacters")}';
+    }
+    return true;
+  }
+
+  bool afterAttributeValueState() {
+    var data = stream.char();
+    if (isWhitespace(data)) {
+      state = beforeAttributeNameState;
+    } else if (data == ">") {
+      emitCurrentToken();
+    } else if (data == "/") {
+      state = selfClosingStartTagState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("unexpected-EOF-after-attribute-value"));
+      stream.unget(data);
+      state = dataState;
+    } else {
+      _addToken(new ParseErrorToken(
+          "unexpected-character-after-attribute-value"));
+      stream.unget(data);
+      state = beforeAttributeNameState;
+    }
+    return true;
+  }
+
+  bool selfClosingStartTagState() {
+    var data = stream.char();
+    if (data == ">") {
+      currentTagToken.selfClosing = true;
+      emitCurrentToken();
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("unexpected-EOF-after-solidus-in-tag"));
+      stream.unget(data);
+      state = dataState;
+    } else {
+      _addToken(new ParseErrorToken(
+          "unexpected-character-after-soldius-in-tag"));
+      stream.unget(data);
+      state = beforeAttributeNameState;
+    }
+    return true;
+  }
+
+  bool bogusCommentState() {
+    // Make a new comment token and give it as value all the characters
+    // until the first > or EOF (charsUntil checks for EOF automatically)
+    // and emit it.
+    var data = stream.charsUntil(">");
+    data = data.replaceAll("\u0000", "\uFFFD");
+    _addToken(new CommentToken(data));
+
+    // Eat the character directly after the bogus comment which is either a
+    // ">" or an EOF.
+    stream.char();
+    state = dataState;
+    return true;
+  }
+
+  bool markupDeclarationOpenState() {
+    var charStack = [stream.char()];
+    if (charStack.last == "-") {
+      charStack.add(stream.char());
+      if (charStack.last == "-") {
+        currentToken = new CommentToken("");
+        state = commentStartState;
+        return true;
+      }
+    } else if (charStack.last == 'd' || charStack.last == 'D') {
+      var matched = true;
+      for (var expected in const ['oO', 'cC', 'tT', 'yY', 'pP', 'eE']) {
+        var char = stream.char();
+        charStack.add(char);
+        if (char == EOF || !expected.contains(char)) {
+          matched = false;
+          break;
+        }
+      }
+      if (matched) {
+        currentToken = new DoctypeToken(correct: true);
+        state = doctypeState;
+        return true;
+      }
+    } else if (charStack.last == "[" &&
+        parser != null && parser.tree.openElements.length > 0 &&
+        parser.tree.openElements.last.namespaceUri
+            != parser.tree.defaultNamespace) {
+      var matched = true;
+      for (var expected in const ["C", "D", "A", "T", "A", "["]) {
+        charStack.add(stream.char());
+        if (charStack.last != expected) {
+          matched = false;
+          break;
+        }
+      }
+      if (matched) {
+        state = cdataSectionState;
+        return true;
+      }
+    }
+
+    _addToken(new ParseErrorToken("expected-dashes-or-doctype"));
+
+    while (charStack.length > 0) {
+      stream.unget(charStack.removeLast());
+    }
+    state = bogusCommentState;
+    return true;
+  }
+
+  bool commentStartState() {
+    var data = stream.char();
+    if (data == "-") {
+      state = commentStartDashState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      currentStringToken.data = '${currentStringToken.data}\uFFFD';
+    } else if (data == ">") {
+      _addToken(new ParseErrorToken("incorrect-comment"));
+      _addToken(currentToken);
+      state = dataState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-comment"));
+      _addToken(currentToken);
+      state = dataState;
+    } else {
+      currentStringToken.data = '${currentStringToken.data}$data';
+      state = commentState;
+    }
+    return true;
+  }
+
+  bool commentStartDashState() {
+    var data = stream.char();
+    if (data == "-") {
+      state = commentEndState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      currentStringToken.data = '${currentStringToken.data}-\uFFFD';
+    } else if (data == ">") {
+      _addToken(new ParseErrorToken("incorrect-comment"));
+      _addToken(currentToken);
+      state = dataState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-comment"));
+      _addToken(currentToken);
+      state = dataState;
+    } else {
+      currentStringToken.data = '${currentStringToken.data}-${data}';
+      state = commentState;
+    }
+    return true;
+  }
+
+  bool commentState() {
+    var data = stream.char();
+    if (data == "-") {
+      state = commentEndDashState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      currentStringToken.data = '${currentStringToken.data}\uFFFD';
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-comment"));
+      _addToken(currentToken);
+      state = dataState;
+    } else {
+      currentStringToken.data = '${currentStringToken.data}$data'
+          '${stream.charsUntil("-\u0000")}';
+    }
+    return true;
+  }
+
+  bool commentEndDashState() {
+    var data = stream.char();
+    if (data == "-") {
+      state = commentEndState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      currentStringToken.data = "${currentStringToken.data}-\uFFFD";
+      state = commentState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-comment-end-dash"));
+      _addToken(currentToken);
+      state = dataState;
+    } else {
+      currentStringToken.data = "${currentStringToken.data}-${data}";
+      state = commentState;
+    }
+    return true;
+  }
+
+  bool commentEndState() {
+    var data = stream.char();
+    if (data == ">") {
+      _addToken(currentToken);
+      state = dataState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      currentStringToken.data = '${currentStringToken.data}--\uFFFD';
+      state = commentState;
+    } else if (data == "!") {
+      _addToken(new ParseErrorToken(
+          "unexpected-bang-after-double-dash-in-comment"));
+      state = commentEndBangState;
+    } else if (data == "-") {
+      _addToken(new ParseErrorToken(
+          "unexpected-dash-after-double-dash-in-comment"));
+      currentStringToken.data = '${currentStringToken.data}$data';
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-comment-double-dash"));
+      _addToken(currentToken);
+      state = dataState;
+    } else {
+      // XXX
+      _addToken(new ParseErrorToken("unexpected-char-in-comment"));
+      currentStringToken.data = "${currentStringToken.data}--${data}";
+      state = commentState;
+    }
+    return true;
+  }
+
+  bool commentEndBangState() {
+    var data = stream.char();
+    if (data == ">") {
+      _addToken(currentToken);
+      state = dataState;
+    } else if (data == "-") {
+      currentStringToken.data = '${currentStringToken.data}--!';
+      state = commentEndDashState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      currentStringToken.data = '${currentStringToken.data}--!\uFFFD';
+      state = commentState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-comment-end-bang-state"));
+      _addToken(currentToken);
+      state = dataState;
+    } else {
+      currentStringToken.data = "${currentStringToken.data}--!${data}";
+      state = commentState;
+    }
+    return true;
+  }
+
+  bool doctypeState() {
+    var data = stream.char();
+    if (isWhitespace(data)) {
+      state = beforeDoctypeNameState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken(
+          "expected-doctype-name-but-got-eof"));
+      currentDoctypeToken.correct = false;
+      _addToken(currentToken);
+      state = dataState;
+    } else {
+      _addToken(new ParseErrorToken("need-space-after-doctype"));
+      stream.unget(data);
+      state = beforeDoctypeNameState;
+    }
+    return true;
+  }
+
+  bool beforeDoctypeNameState() {
+    var data = stream.char();
+    if (isWhitespace(data)) {
+      return true;
+    } else if (data == ">") {
+      _addToken(new ParseErrorToken(
+          "expected-doctype-name-but-got-right-bracket"));
+      currentDoctypeToken.correct = false;
+      _addToken(currentToken);
+      state = dataState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      currentDoctypeToken.name = "\uFFFD";
+      state = doctypeNameState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken(
+          "expected-doctype-name-but-got-eof"));
+      currentDoctypeToken.correct = false;
+      _addToken(currentToken);
+      state = dataState;
+    } else {
+      currentDoctypeToken.name = data;
+      state = doctypeNameState;
+    }
+    return true;
+  }
+
+  bool doctypeNameState() {
+    var data = stream.char();
+    if (isWhitespace(data)) {
+      currentDoctypeToken.name = asciiUpper2Lower(currentDoctypeToken.name);
+      state = afterDoctypeNameState;
+    } else if (data == ">") {
+      currentDoctypeToken.name = asciiUpper2Lower(currentDoctypeToken.name);
+      _addToken(currentToken);
+      state = dataState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      currentDoctypeToken.name = "${currentDoctypeToken.name}\uFFFD";
+      state = doctypeNameState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-doctype-name"));
+      currentDoctypeToken.correct = false;
+      currentDoctypeToken.name = asciiUpper2Lower(currentDoctypeToken.name);
+      _addToken(currentToken);
+      state = dataState;
+    } else {
+      currentDoctypeToken.name = '${currentDoctypeToken.name}$data';
+    }
+    return true;
+  }
+
+  bool afterDoctypeNameState() {
+    var data = stream.char();
+    if (isWhitespace(data)) {
+      return true;
+    } else if (data == ">") {
+      _addToken(currentToken);
+      state = dataState;
+    } else if (data == EOF) {
+      currentDoctypeToken.correct = false;
+      stream.unget(data);
+      _addToken(new ParseErrorToken("eof-in-doctype"));
+      _addToken(currentToken);
+      state = dataState;
+    } else {
+      if (data == "p" || data == "P") {
+        // TODO(jmesserly): would be nice to have a helper for this.
+        var matched = true;
+        for (var expected in const ["uU", "bB", "lL", "iI", "cC"]) {
+          data = stream.char();
+          if (data == EOF || !expected.contains(data)) {
+            matched = false;
+            break;
+          }
+        }
+        if (matched) {
+          state = afterDoctypePublicKeywordState;
+          return true;
+        }
+      } else if (data == "s" || data == "S") {
+        var matched = true;
+        for (var expected in const ["yY", "sS", "tT", "eE", "mM"]) {
+          data = stream.char();
+          if (data == EOF || !expected.contains(data)) {
+            matched = false;
+            break;
+          }
+        }
+        if (matched) {
+          state = afterDoctypeSystemKeywordState;
+          return true;
+        }
+      }
+
+      // All the characters read before the current 'data' will be
+      // [a-zA-Z], so they're garbage in the bogus doctype and can be
+      // discarded; only the latest character might be '>' or EOF
+      // and needs to be ungetted
+      stream.unget(data);
+      _addToken(new ParseErrorToken(
+          "expected-space-or-right-bracket-in-doctype",
+          messageParams: {"data": data}));
+      currentDoctypeToken.correct = false;
+      state = bogusDoctypeState;
+    }
+    return true;
+  }
+
+  bool afterDoctypePublicKeywordState() {
+    var data = stream.char();
+    if (isWhitespace(data)) {
+      state = beforeDoctypePublicIdentifierState;
+    } else if (data == "'" || data == '"') {
+      _addToken(new ParseErrorToken("unexpected-char-in-doctype"));
+      stream.unget(data);
+      state = beforeDoctypePublicIdentifierState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-doctype"));
+      currentDoctypeToken.correct = false;
+      _addToken(currentToken);
+      state = dataState;
+    } else {
+      stream.unget(data);
+      state = beforeDoctypePublicIdentifierState;
+    }
+    return true;
+  }
+
+  bool beforeDoctypePublicIdentifierState() {
+    var data = stream.char();
+    if (isWhitespace(data)) {
+      return true;
+    } else if (data == "\"") {
+      currentDoctypeToken.publicId = "";
+      state = doctypePublicIdentifierDoubleQuotedState;
+    } else if (data == "'") {
+      currentDoctypeToken.publicId = "";
+      state = doctypePublicIdentifierSingleQuotedState;
+    } else if (data == ">") {
+      _addToken(new ParseErrorToken("unexpected-end-of-doctype"));
+      currentDoctypeToken.correct = false;
+      _addToken(currentToken);
+      state = dataState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-doctype"));
+      currentDoctypeToken.correct = false;
+      _addToken(currentToken);
+      state = dataState;
+    } else {
+      _addToken(new ParseErrorToken("unexpected-char-in-doctype"));
+      currentDoctypeToken.correct = false;
+      state = bogusDoctypeState;
+    }
+    return true;
+  }
+
+  bool doctypePublicIdentifierDoubleQuotedState() {
+    var data = stream.char();
+    if (data == '"') {
+      state = afterDoctypePublicIdentifierState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      currentDoctypeToken.publicId = "${currentDoctypeToken.publicId}\uFFFD";
+    } else if (data == ">") {
+      _addToken(new ParseErrorToken("unexpected-end-of-doctype"));
+      currentDoctypeToken.correct = false;
+      _addToken(currentToken);
+      state = dataState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-doctype"));
+      currentDoctypeToken.correct = false;
+      _addToken(currentToken);
+      state = dataState;
+    } else {
+      currentDoctypeToken.publicId = '${currentDoctypeToken.publicId}$data';
+    }
+    return true;
+  }
+
+  bool doctypePublicIdentifierSingleQuotedState() {
+    var data = stream.char();
+    if (data == "'") {
+      state = afterDoctypePublicIdentifierState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      currentDoctypeToken.publicId = "${currentDoctypeToken.publicId}\uFFFD";
+    } else if (data == ">") {
+      _addToken(new ParseErrorToken("unexpected-end-of-doctype"));
+      currentDoctypeToken.correct = false;
+      _addToken(currentToken);
+      state = dataState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-doctype"));
+      currentDoctypeToken.correct = false;
+      _addToken(currentToken);
+      state = dataState;
+    } else {
+      currentDoctypeToken.publicId = '${currentDoctypeToken.publicId}$data';
+    }
+    return true;
+  }
+
+  bool afterDoctypePublicIdentifierState() {
+    var data = stream.char();
+    if (isWhitespace(data)) {
+      state = betweenDoctypePublicAndSystemIdentifiersState;
+    } else if (data == ">") {
+      _addToken(currentToken);
+      state = dataState;
+    } else if (data == '"') {
+      _addToken(new ParseErrorToken("unexpected-char-in-doctype"));
+      currentDoctypeToken.systemId = "";
+      state = doctypeSystemIdentifierDoubleQuotedState;
+    } else if (data == "'") {
+      _addToken(new ParseErrorToken("unexpected-char-in-doctype"));
+      currentDoctypeToken.systemId = "";
+      state = doctypeSystemIdentifierSingleQuotedState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-doctype"));
+      currentDoctypeToken.correct = false;
+      _addToken(currentToken);
+      state = dataState;
+    } else {
+      _addToken(new ParseErrorToken("unexpected-char-in-doctype"));
+      currentDoctypeToken.correct = false;
+      state = bogusDoctypeState;
+    }
+    return true;
+  }
+
+  bool betweenDoctypePublicAndSystemIdentifiersState() {
+    var data = stream.char();
+    if (isWhitespace(data)) {
+      return true;
+    } else if (data == ">") {
+      _addToken(currentToken);
+      state = dataState;
+    } else if (data == '"') {
+      currentDoctypeToken.systemId = "";
+      state = doctypeSystemIdentifierDoubleQuotedState;
+    } else if (data == "'") {
+      currentDoctypeToken.systemId = "";
+      state = doctypeSystemIdentifierSingleQuotedState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-doctype"));
+      currentDoctypeToken.correct = false;
+      _addToken(currentToken);
+      state = dataState;
+    } else {
+      _addToken(new ParseErrorToken("unexpected-char-in-doctype"));
+      currentDoctypeToken.correct = false;
+      state = bogusDoctypeState;
+    }
+    return true;
+  }
+
+  bool afterDoctypeSystemKeywordState() {
+    var data = stream.char();
+    if (isWhitespace(data)) {
+      state = beforeDoctypeSystemIdentifierState;
+    } else if (data == "'" || data == '"') {
+      _addToken(new ParseErrorToken("unexpected-char-in-doctype"));
+      stream.unget(data);
+      state = beforeDoctypeSystemIdentifierState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-doctype"));
+      currentDoctypeToken.correct = false;
+      _addToken(currentToken);
+      state = dataState;
+    } else {
+      stream.unget(data);
+      state = beforeDoctypeSystemIdentifierState;
+    }
+    return true;
+  }
+
+  bool beforeDoctypeSystemIdentifierState() {
+    var data = stream.char();
+    if (isWhitespace(data)) {
+      return true;
+    } else if (data == "\"") {
+      currentDoctypeToken.systemId = "";
+      state = doctypeSystemIdentifierDoubleQuotedState;
+    } else if (data == "'") {
+      currentDoctypeToken.systemId = "";
+      state = doctypeSystemIdentifierSingleQuotedState;
+    } else if (data == ">") {
+      _addToken(new ParseErrorToken("unexpected-char-in-doctype"));
+      currentDoctypeToken.correct = false;
+      _addToken(currentToken);
+      state = dataState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-doctype"));
+      currentDoctypeToken.correct = false;
+      _addToken(currentToken);
+      state = dataState;
+    } else {
+      _addToken(new ParseErrorToken("unexpected-char-in-doctype"));
+      currentDoctypeToken.correct = false;
+      state = bogusDoctypeState;
+    }
+    return true;
+  }
+
+  bool doctypeSystemIdentifierDoubleQuotedState() {
+    var data = stream.char();
+    if (data == "\"") {
+      state = afterDoctypeSystemIdentifierState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      currentDoctypeToken.systemId = "${currentDoctypeToken.systemId}\uFFFD";
+    } else if (data == ">") {
+      _addToken(new ParseErrorToken("unexpected-end-of-doctype"));
+      currentDoctypeToken.correct = false;
+      _addToken(currentToken);
+      state = dataState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-doctype"));
+      currentDoctypeToken.correct = false;
+      _addToken(currentToken);
+      state = dataState;
+    } else {
+      currentDoctypeToken.systemId = '${currentDoctypeToken.systemId}$data';
+    }
+    return true;
+  }
+
+  bool doctypeSystemIdentifierSingleQuotedState() {
+    var data = stream.char();
+    if (data == "'") {
+      state = afterDoctypeSystemIdentifierState;
+    } else if (data == "\u0000") {
+      _addToken(new ParseErrorToken("invalid-codepoint"));
+      currentDoctypeToken.systemId = "${currentDoctypeToken.systemId}\uFFFD";
+    } else if (data == ">") {
+      _addToken(new ParseErrorToken("unexpected-end-of-doctype"));
+      currentDoctypeToken.correct = false;
+      _addToken(currentToken);
+      state = dataState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-doctype"));
+      currentDoctypeToken.correct = false;
+      _addToken(currentToken);
+      state = dataState;
+    } else {
+      currentDoctypeToken.systemId = '${currentDoctypeToken.systemId}$data';
+    }
+    return true;
+  }
+
+  bool afterDoctypeSystemIdentifierState() {
+    var data = stream.char();
+    if (isWhitespace(data)) {
+      return true;
+    } else if (data == ">") {
+      _addToken(currentToken);
+      state = dataState;
+    } else if (data == EOF) {
+      _addToken(new ParseErrorToken("eof-in-doctype"));
+      currentDoctypeToken.correct = false;
+      _addToken(currentToken);
+      state = dataState;
+    } else {
+      _addToken(new ParseErrorToken("unexpected-char-in-doctype"));
+      state = bogusDoctypeState;
+    }
+    return true;
+  }
+
+  bool bogusDoctypeState() {
+    var data = stream.char();
+    if (data == ">") {
+      _addToken(currentToken);
+      state = dataState;
+    } else if (data == EOF) {
+      // XXX EMIT
+      stream.unget(data);
+      _addToken(currentToken);
+      state = dataState;
+    }
+    return true;
+  }
+
+  bool cdataSectionState() {
+    var data = [];
+    int matchedEnd = 0;
+    while (true) {
+      var ch = stream.char();
+      if (ch == EOF) {
+        break;
+      }
+      // Deal with null here rather than in the parser
+      if (ch == "\u0000") {
+        _addToken(new ParseErrorToken("invalid-codepoint"));
+        ch = "\uFFFD";
+      }
+      data.add(ch);
+      // TODO(jmesserly): it'd be nice if we had an easier way to match the end,
+      // perhaps with a "peek" API.
+      if (ch == "]" && matchedEnd < 2) {
+        matchedEnd++;
+      } else if (ch == ">" && matchedEnd == 2) {
+        // Remove "]]>" from the end.
+        data.removeLast();
+        data.removeLast();
+        data.removeLast();
+        break;
+      } else {
+        matchedEnd = 0;
+      }
+    }
+
+    if (data.length > 0) {
+      _addToken(new CharactersToken(data.join()));
+    }
+    state = dataState;
+    return true;
+  }
+}
+