pkg/analyzer_experimental/lib/src/generated/parser.dart

// This code was auto-generated, is not intended to be edited, and is subject to
// significant change. Please see the README file for more information.

library engine.parser;

import 'dart:collection';
import 'java_core.dart';
import 'java_engine.dart';
import 'instrumentation.dart';
import 'error.dart';
import 'source.dart';
import 'scanner.dart';
import 'ast.dart';
import 'utilities_dart.dart';

/**
 * Instances of the class {@code CommentAndMetadata} implement a simple data-holder for a method
 * that needs to return multiple values.
 * @coverage dart.engine.parser
 */
class CommentAndMetadata {
  /**
   * The documentation comment that was parsed, or {@code null} if none was given.
   */
  Comment _comment;
  /**
   * The metadata that was parsed.
   */
  List<Annotation> _metadata;
  /**
   * Initialize a newly created holder with the given data.
   * @param comment the documentation comment that was parsed
   * @param metadata the metadata that was parsed
   */
  CommentAndMetadata(Comment comment, List<Annotation> metadata) {
    this._comment = comment;
    this._metadata = metadata;
  }
  /**
   * Return the documentation comment that was parsed, or {@code null} if none was given.
   * @return the documentation comment that was parsed
   */
  Comment get comment => _comment;
  /**
   * Return the metadata that was parsed. If there was no metadata, then the list will be empty.
   * @return the metadata that was parsed
   */
  List<Annotation> get metadata => _metadata;
}
/**
 * Instances of the class {@code FinalConstVarOrType} implement a simple data-holder for a method
 * that needs to return multiple values.
 * @coverage dart.engine.parser
 */
class FinalConstVarOrType {
  /**
   * The 'final', 'const' or 'var' keyword, or {@code null} if none was given.
   */
  Token _keyword;
  /**
   * The type, of {@code null} if no type was specified.
   */
  TypeName _type;
  /**
   * Initialize a newly created holder with the given data.
   * @param keyword the 'final', 'const' or 'var' keyword
   * @param type the type
   */
  FinalConstVarOrType(Token keyword, TypeName type) {
    this._keyword = keyword;
    this._type = type;
  }
  /**
   * Return the 'final', 'const' or 'var' keyword, or {@code null} if none was given.
   * @return the 'final', 'const' or 'var' keyword
   */
  Token get keyword => _keyword;
  /**
   * Return the type, of {@code null} if no type was specified.
   * @return the type
   */
  TypeName get type => _type;
}
/**
 * Instances of the class {@code Modifiers} implement a simple data-holder for a method that needs
 * to return multiple values.
 * @coverage dart.engine.parser
 */
class Modifiers {
  /**
   * The token representing the keyword 'abstract', or {@code null} if the keyword was not found.
   */
  Token _abstractKeyword;
  /**
   * The token representing the keyword 'const', or {@code null} if the keyword was not found.
   */
  Token _constKeyword;
  /**
   * The token representing the keyword 'external', or {@code null} if the keyword was not found.
   */
  Token _externalKeyword;
  /**
   * The token representing the keyword 'factory', or {@code null} if the keyword was not found.
   */
  Token _factoryKeyword;
  /**
   * The token representing the keyword 'final', or {@code null} if the keyword was not found.
   */
  Token _finalKeyword;
  /**
   * The token representing the keyword 'static', or {@code null} if the keyword was not found.
   */
  Token _staticKeyword;
  /**
   * The token representing the keyword 'var', or {@code null} if the keyword was not found.
   */
  Token _varKeyword;
  /**
   * Initialize a newly created and empty set of modifiers.
   */
  Modifiers() : super() {
  }
  /**
   * Return the token representing the keyword 'abstract', or {@code null} if the keyword was not
   * found.
   * @return the token representing the keyword 'abstract'
   */
  Token get abstractKeyword => _abstractKeyword;
  /**
   * Return the token representing the keyword 'const', or {@code null} if the keyword was not
   * found.
   * @return the token representing the keyword 'const'
   */
  Token get constKeyword => _constKeyword;
  /**
   * Return the token representing the keyword 'external', or {@code null} if the keyword was not
   * found.
   * @return the token representing the keyword 'external'
   */
  Token get externalKeyword => _externalKeyword;
  /**
   * Return the token representing the keyword 'factory', or {@code null} if the keyword was not
   * found.
   * @return the token representing the keyword 'factory'
   */
  Token get factoryKeyword => _factoryKeyword;
  /**
   * Return the token representing the keyword 'final', or {@code null} if the keyword was not
   * found.
   * @return the token representing the keyword 'final'
   */
  Token get finalKeyword => _finalKeyword;
  /**
   * Return the token representing the keyword 'static', or {@code null} if the keyword was not
   * found.
   * @return the token representing the keyword 'static'
   */
  Token get staticKeyword => _staticKeyword;
  /**
   * Return the token representing the keyword 'var', or {@code null} if the keyword was not found.
   * @return the token representing the keyword 'var'
   */
  Token get varKeyword => _varKeyword;
  /**
   * Set the token representing the keyword 'abstract' to the given token.
   * @param abstractKeyword the token representing the keyword 'abstract'
   */
  void set abstractKeyword(Token abstractKeyword2) {
    this._abstractKeyword = abstractKeyword2;
  }
  /**
   * Set the token representing the keyword 'const' to the given token.
   * @param constKeyword the token representing the keyword 'const'
   */
  void set constKeyword(Token constKeyword2) {
    this._constKeyword = constKeyword2;
  }
  /**
   * Set the token representing the keyword 'external' to the given token.
   * @param externalKeyword the token representing the keyword 'external'
   */
  void set externalKeyword(Token externalKeyword2) {
    this._externalKeyword = externalKeyword2;
  }
  /**
   * Set the token representing the keyword 'factory' to the given token.
   * @param factoryKeyword the token representing the keyword 'factory'
   */
  void set factoryKeyword(Token factoryKeyword2) {
    this._factoryKeyword = factoryKeyword2;
  }
  /**
   * Set the token representing the keyword 'final' to the given token.
   * @param finalKeyword the token representing the keyword 'final'
   */
  void set finalKeyword(Token finalKeyword2) {
    this._finalKeyword = finalKeyword2;
  }
  /**
   * Set the token representing the keyword 'static' to the given token.
   * @param staticKeyword the token representing the keyword 'static'
   */
  void set staticKeyword(Token staticKeyword2) {
    this._staticKeyword = staticKeyword2;
  }
  /**
   * Set the token representing the keyword 'var' to the given token.
   * @param varKeyword the token representing the keyword 'var'
   */
  void set varKeyword(Token varKeyword2) {
    this._varKeyword = varKeyword2;
  }
  String toString() {
    JavaStringBuilder builder = new JavaStringBuilder();
    bool needsSpace = appendKeyword(builder, false, _abstractKeyword);
    needsSpace = appendKeyword(builder, needsSpace, _constKeyword);
    needsSpace = appendKeyword(builder, needsSpace, _externalKeyword);
    needsSpace = appendKeyword(builder, needsSpace, _factoryKeyword);
    needsSpace = appendKeyword(builder, needsSpace, _finalKeyword);
    needsSpace = appendKeyword(builder, needsSpace, _staticKeyword);
    appendKeyword(builder, needsSpace, _varKeyword);
    return builder.toString();
  }
  /**
   * If the given keyword is not {@code null}, append it to the given builder, prefixing it with a
   * space if needed.
   * @param builder the builder to which the keyword will be appended
   * @param needsSpace {@code true} if the keyword needs to be prefixed with a space
   * @param keyword the keyword to be appended
   * @return {@code true} if subsequent keywords need to be prefixed with a space
   */
  bool appendKeyword(JavaStringBuilder builder, bool needsSpace, Token keyword) {
    if (keyword != null) {
      if (needsSpace) {
        builder.appendChar(0x20);
      }
      builder.append(keyword.lexeme);
      return true;
    }
    return needsSpace;
  }
}
/**
 * Instances of the class {@code Parser} are used to parse tokens into an AST structure.
 * @coverage dart.engine.parser
 */
class Parser {
  /**
   * The source being parsed.
   */
  Source _source;
  /**
   * The error listener that will be informed of any errors that are found during the parse.
   */
  AnalysisErrorListener _errorListener;
  /**
   * The next token to be parsed.
   */
  Token _currentToken;
  /**
   * A flag indicating whether the parser is currently in the body of a loop.
   */
  bool _inLoop = false;
  /**
   * A flag indicating whether the parser is currently in a switch statement.
   */
  bool _inSwitch = false;
  static String _HIDE = "hide";
  static String _OF = "of";
  static String _ON = "on";
  static String _SHOW = "show";
  static String _NATIVE = "native";
  /**
   * Initialize a newly created parser.
   * @param source the source being parsed
   * @param errorListener the error listener that will be informed of any errors that are found
   * during the parse
   */
  Parser(Source source, AnalysisErrorListener errorListener) {
    this._source = source;
    this._errorListener = errorListener;
  }
  /**
   * Parse a compilation unit, starting with the given token.
   * @param token the first token of the compilation unit
   * @return the compilation unit that was parsed
   */
  CompilationUnit parseCompilationUnit(Token token) {
    InstrumentationBuilder instrumentation = Instrumentation.builder2("dart.engine.Parser.parseCompilationUnit");
    try {
      _currentToken = token;
      return parseCompilationUnit2();
    } finally {
      instrumentation.log();
    }
  }
  /**
   * Parse an expression, starting with the given token.
   * @param token the first token of the expression
   * @return the expression that was parsed, or {@code null} if the tokens do not represent a
   * recognizable expression
   */
  Expression parseExpression(Token token) {
    InstrumentationBuilder instrumentation = Instrumentation.builder2("dart.engine.Parser.parseExpression");
    try {
      _currentToken = token;
      return parseExpression2();
    } finally {
      instrumentation.log();
    }
  }
  /**
   * Parse a statement, starting with the given token.
   * @param token the first token of the statement
   * @return the statement that was parsed, or {@code null} if the tokens do not represent a
   * recognizable statement
   */
  Statement parseStatement(Token token) {
    InstrumentationBuilder instrumentation = Instrumentation.builder2("dart.engine.Parser.parseStatement");
    try {
      _currentToken = token;
      return parseStatement2();
    } finally {
      instrumentation.log();
    }
  }
  /**
   * Parse a sequence of statements, starting with the given token.
   * @param token the first token of the sequence of statement
   * @return the statements that were parsed, or {@code null} if the tokens do not represent a
   * recognizable sequence of statements
   */
  List<Statement> parseStatements(Token token) {
    InstrumentationBuilder instrumentation = Instrumentation.builder2("dart.engine.Parser.parseStatements");
    try {
      _currentToken = token;
      return parseStatements2();
    } finally {
      instrumentation.log();
    }
  }
  void set currentToken(Token currentToken2) {
    this._currentToken = currentToken2;
  }
  /**
   * Advance to the next token in the token stream.
   */
  void advance() {
    _currentToken = _currentToken.next;
  }
  /**
   * Append the character equivalent of the given scalar value to the given builder. Use the start
   * and end indices to report an error, and don't append anything to the builder, if the scalar
   * value is invalid.
   * @param builder the builder to which the scalar value is to be appended
   * @param escapeSequence the escape sequence that was parsed to produce the scalar value
   * @param scalarValue the value to be appended
   * @param startIndex the index of the first character representing the scalar value
   * @param endIndex the index of the last character representing the scalar value
   */
  void appendScalarValue(JavaStringBuilder builder, String escapeSequence, int scalarValue, int startIndex, int endIndex) {
    if (scalarValue < 0 || scalarValue > Character.MAX_CODE_POINT || (scalarValue >= 0xD800 && scalarValue <= 0xDFFF)) {
      reportError4(ParserErrorCode.INVALID_CODE_POINT, [escapeSequence]);
      return;
    }
    if (scalarValue < Character.MAX_VALUE) {
      builder.appendChar((scalarValue as int));
    } else {
      builder.append(Character.toChars(scalarValue));
    }
  }
  /**
   * Compute the content of a string with the given literal representation.
   * @param lexeme the literal representation of the string
   * @return the actual value of the string
   */
  String computeStringValue(String lexeme) {
    if (lexeme.startsWith("r\"\"\"") || lexeme.startsWith("r'''")) {
      if (lexeme.length > 4) {
        return lexeme.substring(4, lexeme.length - 3);
      }
    } else if (lexeme.startsWith("r\"") || lexeme.startsWith("r'")) {
      if (lexeme.length > 2) {
        return lexeme.substring(2, lexeme.length - 1);
      }
    }
    int start = 0;
    if (lexeme.startsWith("\"\"\"") || lexeme.startsWith("'''")) {
      start += 3;
    } else if (lexeme.startsWith("\"") || lexeme.startsWith("'")) {
      start += 1;
    }
    int end = lexeme.length;
    if (end > 3 && (lexeme.endsWith("\"\"\"") || lexeme.endsWith("'''"))) {
      end -= 3;
    } else if (end > 1 && (lexeme.endsWith("\"") || lexeme.endsWith("'"))) {
      end -= 1;
    }
    JavaStringBuilder builder = new JavaStringBuilder();
    int index = start;
    while (index < end) {
      index = translateCharacter(builder, lexeme, index);
    }
    return builder.toString();
  }
  /**
   * Create a synthetic identifier.
   * @return the synthetic identifier that was created
   */
  SimpleIdentifier createSyntheticIdentifier() => new SimpleIdentifier.full(createSyntheticToken2(TokenType.IDENTIFIER));
  /**
   * Create a synthetic string literal.
   * @return the synthetic string literal that was created
   */
  SimpleStringLiteral createSyntheticStringLiteral() => new SimpleStringLiteral.full(createSyntheticToken2(TokenType.STRING), "");
  /**
   * Create a synthetic token representing the given keyword.
   * @return the synthetic token that was created
   */
  Token createSyntheticToken(Keyword keyword) => new KeywordToken_11(keyword, _currentToken.offset);
  /**
   * Create a synthetic token with the given type.
   * @return the synthetic token that was created
   */
  Token createSyntheticToken2(TokenType type) => new StringToken(type, "", _currentToken.offset);
  /**
   * Check that the given expression is assignable and report an error if it isn't.
   * <pre>
   * assignableExpression ::=
   * primary (arguments* assignableSelector)+
   * | 'super' assignableSelector
   * | identifier
   * assignableSelector ::=
   * '\[' expression '\]'
   * | '.' identifier
   * </pre>
   * @param expression the expression being checked
   */
  void ensureAssignable(Expression expression) {
    if (expression != null && !expression.isAssignable()) {
      reportError4(ParserErrorCode.ILLEGAL_ASSIGNMENT_TO_NON_ASSIGNABLE, []);
    }
  }
  /**
   * If the current token is a keyword matching the given string, return it after advancing to the
   * next token. Otherwise report an error and return the current token without advancing.
   * @param keyword the keyword that is expected
   * @return the token that matched the given type
   */
  Token expect(Keyword keyword) {
    if (matches(keyword)) {
      return andAdvance;
    }
    reportError4(ParserErrorCode.EXPECTED_TOKEN, [keyword.syntax]);
    return _currentToken;
  }
  /**
   * If the current token has the expected type, return it after advancing to the next token.
   * Otherwise report an error and return the current token without advancing.
   * @param type the type of token that is expected
   * @return the token that matched the given type
   */
  Token expect2(TokenType type) {
    if (matches5(type)) {
      return andAdvance;
    }
    if (identical(type, TokenType.SEMICOLON)) {
      reportError5(ParserErrorCode.EXPECTED_TOKEN, _currentToken.previous, [type.lexeme]);
    } else {
      reportError4(ParserErrorCode.EXPECTED_TOKEN, [type.lexeme]);
    }
    return _currentToken;
  }
  /**
   * Search the given list of ranges for a range that contains the given index. Return the range
   * that was found, or {@code null} if none of the ranges contain the index.
   * @param ranges the ranges to be searched
   * @param index the index contained in the returned range
   * @return the range that was found
   */
  List<int> findRange(List<List<int>> ranges, int index) {
    for (List<int> range in ranges) {
      if (range[0] <= index && index <= range[1]) {
        return range;
      } else if (index < range[0]) {
        return null;
      }
    }
    return null;
  }
  /**
   * Advance to the next token in the token stream, making it the new current token.
   * @return the token that was current before this method was invoked
   */
  Token get andAdvance {
    Token token = _currentToken;
    advance();
    return token;
  }
  /**
   * Return a list of the ranges of characters in the given comment string that should be treated as
   * code blocks.
   * @param comment the comment being processed
   * @return the ranges of characters that should be treated as code blocks
   */
  List<List<int>> getCodeBlockRanges(String comment) {
    List<List<int>> ranges = new List<List<int>>();
    int length2 = comment.length;
    int index = 0;
    if (comment.startsWith("/**") || comment.startsWith("///")) {
      index = 3;
    }
    while (index < length2) {
      int currentChar = comment.codeUnitAt(index);
      if (currentChar == 0xD || currentChar == 0xA) {
        index = index + 1;
        while (index < length2 && Character.isWhitespace(comment.codeUnitAt(index))) {
          index = index + 1;
        }
        if (JavaString.startsWithBefore(comment, "*     ", index)) {
          int end = index + 6;
          while (end < length2 && comment.codeUnitAt(end) != 0xD && comment.codeUnitAt(end) != 0xA) {
            end = end + 1;
          }
          ranges.add(<int> [index, end]);
          index = end;
        }
      } else if (JavaString.startsWithBefore(comment, "[:", index)) {
        int end = comment.indexOf(":]", index + 2);
        if (end < 0) {
          end = length2;
        }
        ranges.add(<int> [index, end]);
        index = end + 1;
      } else {
        index = index + 1;
      }
    }
    return ranges;
  }
  /**
   * Return {@code true} if the current token is the first token of a return type that is followed
   * by an identifier, possibly followed by a list of type parameters, followed by a
   * left-parenthesis. This is used by parseTypeAlias to determine whether or not to parse a return
   * type.
   * @return {@code true} if we can successfully parse the rest of a type alias if we first parse a
   * return type.
   */
  bool hasReturnTypeInTypeAlias() {
    Token next = skipReturnType(_currentToken);
    if (next == null) {
      return false;
    }
    return matchesIdentifier2(next);
  }
  /**
   * Return {@code true} if the current token appears to be the beginning of a function declaration.
   * @return {@code true} if the current token appears to be the beginning of a function declaration
   */
  bool isFunctionDeclaration() {
    if (matches(Keyword.VOID)) {
      return true;
    }
    Token afterReturnType = skipTypeName(_currentToken);
    if (afterReturnType == null) {
      afterReturnType = _currentToken;
    }
    Token afterIdentifier = skipSimpleIdentifier(afterReturnType);
    if (afterIdentifier == null) {
      afterIdentifier = skipSimpleIdentifier(_currentToken);
    }
    if (afterIdentifier == null) {
      return false;
    }
    return isFunctionExpression(afterIdentifier);
  }
  /**
   * Return {@code true} if the given token appears to be the beginning of a function expression.
   * @param startToken the token that might be the start of a function expression
   * @return {@code true} if the given token appears to be the beginning of a function expression
   */
  bool isFunctionExpression(Token startToken) {
    Token afterParameters = skipFormalParameterList(startToken);
    if (afterParameters == null) {
      return false;
    }
    return matchesAny(afterParameters, [TokenType.OPEN_CURLY_BRACKET, TokenType.FUNCTION]);
  }
  /**
   * Return {@code true} if the given character is a valid hexadecimal digit.
   * @param character the character being tested
   * @return {@code true} if the character is a valid hexadecimal digit
   */
  bool isHexDigit(int character) => (0x30 <= character && character <= 0x39) || (0x41 <= character && character <= 0x46) || (0x61 <= character && character <= 0x66);
  /**
   * Return {@code true} if the current token is the first token in an initialized variable
   * declaration rather than an expression. This method assumes that we have already skipped past
   * any metadata that might be associated with the declaration.
   * <pre>
   * initializedVariableDeclaration ::=
   * declaredIdentifier ('=' expression)? (',' initializedIdentifier)
   * declaredIdentifier ::=
   * metadata finalConstVarOrType identifier
   * finalConstVarOrType ::=
   * 'final' type?
   * | 'const' type?
   * | 'var'
   * | type
   * type ::=
   * qualified typeArguments?
   * initializedIdentifier ::=
   * identifier ('=' expression)?
   * </pre>
   * @return {@code true} if the current token is the first token in an initialized variable
   * declaration
   */
  bool isInitializedVariableDeclaration() {
    if (matches(Keyword.FINAL) || matches(Keyword.CONST) || matches(Keyword.VAR)) {
      return true;
    }
    Token token = skipTypeName(_currentToken);
    if (token == null) {
      return false;
    }
    token = skipSimpleIdentifier(token);
    if (token == null) {
      return false;
    }
    TokenType type2 = token.type;
    return identical(type2, TokenType.EQ) || identical(type2, TokenType.COMMA) || identical(type2, TokenType.SEMICOLON) || matches3(token, Keyword.IN);
  }
  /**
   * Given that we have just found bracketed text within a comment, look to see whether that text is
   * (a) followed by a parenthesized link address, (b) followed by a colon, or (c) followed by
   * optional whitespace and another square bracket.
   * <p>
   * This method uses the syntax described by the <a
   * href="http://daringfireball.net/projects/markdown/syntax">markdown</a> project.
   * @param comment the comment text in which the bracketed text was found
   * @param rightIndex the index of the right bracket
   * @return {@code true} if the bracketed text is followed by a link address
   */
  bool isLinkText(String comment, int rightIndex) {
    int length2 = comment.length;
    int index = rightIndex + 1;
    if (index >= length2) {
      return false;
    }
    int nextChar = comment.codeUnitAt(index);
    if (nextChar == 0x28 || nextChar == 0x3A) {
      return true;
    }
    while (Character.isWhitespace(nextChar)) {
      index = index + 1;
      if (index >= length2) {
        return false;
      }
      nextChar = comment.codeUnitAt(index);
    }
    return nextChar == 0x5B;
  }
  /**
   * Return {@code true} if the given token appears to be the beginning of an operator declaration.
   * @param startToken the token that might be the start of an operator declaration
   * @return {@code true} if the given token appears to be the beginning of an operator declaration
   */
  bool isOperator(Token startToken) {
    if (startToken.isOperator()) {
      Token token = startToken.next;
      while (token.isOperator()) {
        token = token.next;
      }
      return matches4(token, TokenType.OPEN_PAREN);
    }
    return false;
  }
  /**
   * Return {@code true} if the current token appears to be the beginning of a switch member.
   * @return {@code true} if the current token appears to be the beginning of a switch member
   */
  bool isSwitchMember() {
    Token token = _currentToken;
    while (matches4(token, TokenType.IDENTIFIER) && matches4(token.next, TokenType.COLON)) {
      token = token.next.next;
    }
    if (identical(token.type, TokenType.KEYWORD)) {
      Keyword keyword2 = ((token as KeywordToken)).keyword;
      return identical(keyword2, Keyword.CASE) || identical(keyword2, Keyword.DEFAULT);
    }
    return false;
  }
  /**
   * Compare the given tokens to find the token that appears first in the source being parsed. That
   * is, return the left-most of all of the tokens. The arguments are allowed to be {@code null}.
   * Return the token with the smallest offset, or {@code null} if there are no arguments or if all
   * of the arguments are {@code null}.
   * @param tokens the tokens being compared
   * @return the token with the smallest offset
   */
  Token lexicallyFirst(List<Token> tokens) {
    Token first = null;
    int firstOffset = 2147483647;
    for (Token token in tokens) {
      if (token != null) {
        int offset2 = token.offset;
        if (offset2 < firstOffset) {
          first = token;
        }
      }
    }
    return first;
  }
  /**
   * Return {@code true} if the current token matches the given keyword.
   * @param keyword the keyword that can optionally appear in the current location
   * @return {@code true} if the current token matches the given keyword
   */
  bool matches(Keyword keyword) => matches3(_currentToken, keyword);
  /**
   * Return {@code true} if the current token matches the given identifier.
   * @param identifier the identifier that can optionally appear in the current location
   * @return {@code true} if the current token matches the given identifier
   */
  bool matches2(String identifier) => identical(_currentToken.type, TokenType.IDENTIFIER) && _currentToken.lexeme == identifier;
  /**
   * Return {@code true} if the given token matches the given keyword.
   * @param token the token being tested
   * @param keyword the keyword that is being tested for
   * @return {@code true} if the given token matches the given keyword
   */
  bool matches3(Token token, Keyword keyword2) => identical(token.type, TokenType.KEYWORD) && identical(((token as KeywordToken)).keyword, keyword2);
  /**
   * Return {@code true} if the given token has the given type.
   * @param token the token being tested
   * @param type the type of token that is being tested for
   * @return {@code true} if the given token has the given type
   */
  bool matches4(Token token, TokenType type2) => identical(token.type, type2);
  /**
   * Return {@code true} if the current token has the given type. Note that this method, unlike
   * other variants, will modify the token stream if possible to match a wider range of tokens. In
   * particular, if we are attempting to match a '>' and the next token is either a '>>' or '>>>',
   * the token stream will be re-written and {@code true} will be returned.
   * @param type the type of token that can optionally appear in the current location
   * @return {@code true} if the current token has the given type
   */
  bool matches5(TokenType type2) {
    TokenType currentType = _currentToken.type;
    if (currentType != type2) {
      if (identical(type2, TokenType.GT)) {
        if (identical(currentType, TokenType.GT_GT)) {
          int offset2 = _currentToken.offset;
          Token first = new Token(TokenType.GT, offset2);
          Token second = new Token(TokenType.GT, offset2 + 1);
          second.setNext(_currentToken.next);
          first.setNext(second);
          _currentToken.previous.setNext(first);
          _currentToken = first;
          return true;
        } else if (identical(currentType, TokenType.GT_EQ)) {
          int offset3 = _currentToken.offset;
          Token first = new Token(TokenType.GT, offset3);
          Token second = new Token(TokenType.EQ, offset3 + 1);
          second.setNext(_currentToken.next);
          first.setNext(second);
          _currentToken.previous.setNext(first);
          _currentToken = first;
          return true;
        } else if (identical(currentType, TokenType.GT_GT_EQ)) {
          int offset4 = _currentToken.offset;
          Token first = new Token(TokenType.GT, offset4);
          Token second = new Token(TokenType.GT, offset4 + 1);
          Token third = new Token(TokenType.EQ, offset4 + 2);
          third.setNext(_currentToken.next);
          second.setNext(third);
          first.setNext(second);
          _currentToken.previous.setNext(first);
          _currentToken = first;
          return true;
        }
      }
      return false;
    }
    return true;
  }
  /**
   * Return {@code true} if the given token has any one of the given types.
   * @param token the token being tested
   * @param types the types of token that are being tested for
   * @return {@code true} if the given token has any of the given types
   */
  bool matchesAny(Token token, List<TokenType> types) {
    TokenType actualType = token.type;
    for (TokenType type in types) {
      if (identical(actualType, type)) {
        return true;
      }
    }
    return false;
  }
  /**
   * Return {@code true} if the current token is a valid identifier. Valid identifiers include
   * built-in identifiers (pseudo-keywords).
   * @return {@code true} if the current token is a valid identifier
   */
  bool matchesIdentifier() => matchesIdentifier2(_currentToken);
  /**
   * Return {@code true} if the given token is a valid identifier. Valid identifiers include
   * built-in identifiers (pseudo-keywords).
   * @return {@code true} if the given token is a valid identifier
   */
  bool matchesIdentifier2(Token token) => matches4(token, TokenType.IDENTIFIER) || (matches4(token, TokenType.KEYWORD) && ((token as KeywordToken)).keyword.isPseudoKeyword());
  /**
   * If the current token has the given type, then advance to the next token and return {@code true}. Otherwise, return {@code false} without advancing.
   * @param type the type of token that can optionally appear in the current location
   * @return {@code true} if the current token has the given type
   */
  bool optional(TokenType type) {
    if (matches5(type)) {
      advance();
      return true;
    }
    return false;
  }
  /**
   * Parse an additive expression.
   * <pre>
   * additiveExpression ::=
   * multiplicativeExpression (additiveOperator multiplicativeExpression)
   * | 'super' (additiveOperator multiplicativeExpression)+
   * </pre>
   * @return the additive expression that was parsed
   */
  Expression parseAdditiveExpression() {
    Expression expression;
    if (matches(Keyword.SUPER) && _currentToken.next.type.isAdditiveOperator()) {
      expression = new SuperExpression.full(andAdvance);
    } else {
      expression = parseMultiplicativeExpression();
    }
    while (_currentToken.type.isAdditiveOperator()) {
      Token operator = andAdvance;
      expression = new BinaryExpression.full(expression, operator, parseMultiplicativeExpression());
    }
    return expression;
  }
  /**
   * Parse an annotation.
   * <pre>
   * annotation ::=
   * '@' qualified ('.' identifier)? arguments?
   * </pre>
   * @return the annotation that was parsed
   */
  Annotation parseAnnotation() {
    Token atSign = expect2(TokenType.AT);
    Identifier name = parsePrefixedIdentifier();
    Token period = null;
    SimpleIdentifier constructorName = null;
    if (matches5(TokenType.PERIOD)) {
      period = andAdvance;
      constructorName = parseSimpleIdentifier();
    }
    ArgumentList arguments = null;
    if (matches5(TokenType.OPEN_PAREN)) {
      arguments = parseArgumentList();
    }
    return new Annotation.full(atSign, name, period, constructorName, arguments);
  }
  /**
   * Parse an argument.
   * <pre>
   * argument ::=
   * namedArgument
   * | expression
   * namedArgument ::=
   * label expression
   * </pre>
   * @return the argument that was parsed
   */
  Expression parseArgument() {
    if (matchesIdentifier() && matches4(peek(), TokenType.COLON)) {
      SimpleIdentifier label = new SimpleIdentifier.full(andAdvance);
      Label name = new Label.full(label, andAdvance);
      return new NamedExpression.full(name, parseExpression2());
    } else {
      return parseExpression2();
    }
  }
  /**
   * Parse an argument definition test.
   * <pre>
   * argumentDefinitionTest ::=
   * '?' identifier
   * </pre>
   * @return the argument definition test that was parsed
   */
  ArgumentDefinitionTest parseArgumentDefinitionTest() {
    Token question = expect2(TokenType.QUESTION);
    SimpleIdentifier identifier = parseSimpleIdentifier();
    return new ArgumentDefinitionTest.full(question, identifier);
  }
  /**
   * Parse a list of arguments.
   * <pre>
   * arguments ::=
   * '(' argumentList? ')'
   * argumentList ::=
   * namedArgument (',' namedArgument)
   * | expressionList (',' namedArgument)
   * </pre>
   * @return the argument list that was parsed
   */
  ArgumentList parseArgumentList() {
    Token leftParenthesis = expect2(TokenType.OPEN_PAREN);
    List<Expression> arguments = new List<Expression>();
    if (matches5(TokenType.CLOSE_PAREN)) {
      return new ArgumentList.full(leftParenthesis, arguments, andAdvance);
    }
    Expression argument = parseArgument();
    arguments.add(argument);
    bool foundNamedArgument = argument is NamedExpression;
    bool generatedError = false;
    while (optional(TokenType.COMMA)) {
      argument = parseArgument();
      arguments.add(argument);
      if (foundNamedArgument) {
        if (!generatedError && argument is! NamedExpression) {
          reportError4(ParserErrorCode.POSITIONAL_AFTER_NAMED_ARGUMENT, []);
          generatedError = true;
        }
      } else if (argument is NamedExpression) {
        foundNamedArgument = true;
      }
    }
    Token rightParenthesis = expect2(TokenType.CLOSE_PAREN);
    return new ArgumentList.full(leftParenthesis, arguments, rightParenthesis);
  }
  /**
   * Parse an assert statement.
   * <pre>
   * assertStatement ::=
   * 'assert' '(' conditionalExpression ')' ';'
   * </pre>
   * @return the assert statement
   */
  AssertStatement parseAssertStatement() {
    Token keyword = expect(Keyword.ASSERT);
    Token leftParen = expect2(TokenType.OPEN_PAREN);
    Expression expression = parseConditionalExpression();
    Token rightParen = expect2(TokenType.CLOSE_PAREN);
    Token semicolon = expect2(TokenType.SEMICOLON);
    return new AssertStatement.full(keyword, leftParen, expression, rightParen, semicolon);
  }
  /**
   * Parse an assignable expression.
   * <pre>
   * assignableExpression ::=
   * primary (arguments* assignableSelector)+
   * | 'super' assignableSelector
   * | identifier
   * </pre>
   * @param primaryAllowed {@code true} if the expression is allowed to be a primary without any
   * assignable selector
   * @return the assignable expression that was parsed
   */
  Expression parseAssignableExpression(bool primaryAllowed) {
    if (matches(Keyword.SUPER)) {
      return parseAssignableSelector(new SuperExpression.full(andAdvance), false);
    }
    Expression expression = parsePrimaryExpression();
    bool isOptional = primaryAllowed || expression is SimpleIdentifier;
    while (true) {
      while (matches5(TokenType.OPEN_PAREN)) {
        ArgumentList argumentList = parseArgumentList();
        if (expression is SimpleIdentifier) {
          expression = new MethodInvocation.full(null, null, (expression as SimpleIdentifier), argumentList);
        } else if (expression is PrefixedIdentifier) {
          PrefixedIdentifier identifier = expression as PrefixedIdentifier;
          expression = new MethodInvocation.full(identifier.prefix, identifier.period, identifier.identifier, argumentList);
        } else if (expression is PropertyAccess) {
          PropertyAccess access = expression as PropertyAccess;
          expression = new MethodInvocation.full(access.target, access.operator, access.propertyName, argumentList);
        } else {
          expression = new FunctionExpressionInvocation.full(expression, argumentList);
        }
        if (!primaryAllowed) {
          isOptional = false;
        }
      }
      Expression selectorExpression = parseAssignableSelector(expression, isOptional || (expression is PrefixedIdentifier));
      if (identical(selectorExpression, expression)) {
        if (!isOptional && (expression is PrefixedIdentifier)) {
          PrefixedIdentifier identifier = expression as PrefixedIdentifier;
          expression = new PropertyAccess.full(identifier.prefix, identifier.period, identifier.identifier);
        }
        return expression;
      }
      expression = selectorExpression;
      isOptional = true;
    }
  }
  /**
   * Parse an assignable selector.
   * <pre>
   * assignableSelector ::=
   * '\[' expression '\]'
   * | '.' identifier
   * </pre>
   * @param prefix the expression preceding the selector
   * @param optional {@code true} if the selector is optional
   * @return the assignable selector that was parsed
   */
  Expression parseAssignableSelector(Expression prefix, bool optional) {
    if (matches5(TokenType.OPEN_SQUARE_BRACKET)) {
      Token leftBracket = andAdvance;
      Expression index = parseExpression2();
      Token rightBracket = expect2(TokenType.CLOSE_SQUARE_BRACKET);
      return new IndexExpression.forTarget_full(prefix, leftBracket, index, rightBracket);
    } else if (matches5(TokenType.PERIOD)) {
      Token period = andAdvance;
      return new PropertyAccess.full(prefix, period, parseSimpleIdentifier());
    } else {
      if (!optional) {
        reportError4(ParserErrorCode.MISSING_ASSIGNABLE_SELECTOR, []);
      }
      return prefix;
    }
  }
  /**
   * Parse a bitwise and expression.
   * <pre>
   * bitwiseAndExpression ::=
   * equalityExpression ('&' equalityExpression)
   * | 'super' ('&' equalityExpression)+
   * </pre>
   * @return the bitwise and expression that was parsed
   */
  Expression parseBitwiseAndExpression() {
    Expression expression;
    if (matches(Keyword.SUPER) && matches4(peek(), TokenType.AMPERSAND)) {
      expression = new SuperExpression.full(andAdvance);
    } else {
      expression = parseEqualityExpression();
    }
    while (matches5(TokenType.AMPERSAND)) {
      Token operator = andAdvance;
      expression = new BinaryExpression.full(expression, operator, parseEqualityExpression());
    }
    return expression;
  }
  /**
   * Parse a bitwise or expression.
   * <pre>
   * bitwiseOrExpression ::=
   * bitwiseXorExpression ('|' bitwiseXorExpression)
   * | 'super' ('|' bitwiseXorExpression)+
   * </pre>
   * @return the bitwise or expression that was parsed
   */
  Expression parseBitwiseOrExpression() {
    Expression expression;
    if (matches(Keyword.SUPER) && matches4(peek(), TokenType.BAR)) {
      expression = new SuperExpression.full(andAdvance);
    } else {
      expression = parseBitwiseXorExpression();
    }
    while (matches5(TokenType.BAR)) {
      Token operator = andAdvance;
      expression = new BinaryExpression.full(expression, operator, parseBitwiseXorExpression());
    }
    return expression;
  }
  /**
   * Parse a bitwise exclusive-or expression.
   * <pre>
   * bitwiseXorExpression ::=
   * bitwiseAndExpression ('^' bitwiseAndExpression)
   * | 'super' ('^' bitwiseAndExpression)+
   * </pre>
   * @return the bitwise exclusive-or expression that was parsed
   */
  Expression parseBitwiseXorExpression() {
    Expression expression;
    if (matches(Keyword.SUPER) && matches4(peek(), TokenType.CARET)) {
      expression = new SuperExpression.full(andAdvance);
    } else {
      expression = parseBitwiseAndExpression();
    }
    while (matches5(TokenType.CARET)) {
      Token operator = andAdvance;
      expression = new BinaryExpression.full(expression, operator, parseBitwiseAndExpression());
    }
    return expression;
  }
  /**
   * Parse a block.
   * <pre>
   * block ::=
   * '{' statements '}'
   * </pre>
   * @return the block that was parsed
   */
  Block parseBlock() {
    Token leftBracket = expect2(TokenType.OPEN_CURLY_BRACKET);
    List<Statement> statements = new List<Statement>();
    Token statementStart = _currentToken;
    while (!matches5(TokenType.EOF) && !matches5(TokenType.CLOSE_CURLY_BRACKET)) {
      Statement statement = parseStatement2();
      if (statement != null) {
        statements.add(statement);
      }
      if (identical(_currentToken, statementStart)) {
        reportError5(ParserErrorCode.UNEXPECTED_TOKEN, _currentToken, [_currentToken.lexeme]);
        advance();
      }
      statementStart = _currentToken;
    }
    Token rightBracket = expect2(TokenType.CLOSE_CURLY_BRACKET);
    return new Block.full(leftBracket, statements, rightBracket);
  }
  /**
   * Parse a break statement.
   * <pre>
   * breakStatement ::=
   * 'break' identifier? ';'
   * </pre>
   * @return the break statement that was parsed
   */
  Statement parseBreakStatement() {
    Token breakKeyword = expect(Keyword.BREAK);
    SimpleIdentifier label = null;
    if (matchesIdentifier()) {
      label = parseSimpleIdentifier();
    }
    if (!_inLoop && !_inSwitch && label == null) {
      reportError5(ParserErrorCode.BREAK_OUTSIDE_OF_LOOP, breakKeyword, []);
    }
    Token semicolon = expect2(TokenType.SEMICOLON);
    return new BreakStatement.full(breakKeyword, label, semicolon);
  }
  /**
   * Parse a cascade section.
   * <pre>
   * cascadeSection ::=
   * '..' (cascadeSelector arguments*) (assignableSelector arguments*)* cascadeAssignment?
   * cascadeSelector ::=
   * '\[' expression '\]'
   * | identifier
   * cascadeAssignment ::=
   * assignmentOperator expressionWithoutCascade
   * </pre>
   * @return the expression representing the cascaded method invocation
   */
  Expression parseCascadeSection() {
    Token period = expect2(TokenType.PERIOD_PERIOD);
    Expression expression = null;
    SimpleIdentifier functionName = null;
    if (matchesIdentifier()) {
      functionName = parseSimpleIdentifier();
    } else if (identical(_currentToken.type, TokenType.OPEN_SQUARE_BRACKET)) {
      Token leftBracket = andAdvance;
      Expression index = parseExpression2();
      Token rightBracket = expect2(TokenType.CLOSE_SQUARE_BRACKET);
      expression = new IndexExpression.forCascade_full(period, leftBracket, index, rightBracket);
      period = null;
    } else {
      reportError5(ParserErrorCode.UNEXPECTED_TOKEN, _currentToken, [_currentToken.lexeme]);
      return expression;
    }
    if (identical(_currentToken.type, TokenType.OPEN_PAREN)) {
      while (identical(_currentToken.type, TokenType.OPEN_PAREN)) {
        if (functionName != null) {
          expression = new MethodInvocation.full(expression, period, functionName, parseArgumentList());
          period = null;
          functionName = null;
        } else if (expression == null) {
          return null;
        } else {
          expression = new FunctionExpressionInvocation.full(expression, parseArgumentList());
        }
      }
    } else if (functionName != null) {
      expression = new PropertyAccess.full(expression, period, functionName);
      period = null;
    }
    bool progress = true;
    while (progress) {
      progress = false;
      Expression selector = parseAssignableSelector(expression, true);
      if (selector != expression) {
        expression = selector;
        progress = true;
        while (identical(_currentToken.type, TokenType.OPEN_PAREN)) {
          expression = new FunctionExpressionInvocation.full(expression, parseArgumentList());
        }
      }
    }
    if (_currentToken.type.isAssignmentOperator()) {
      Token operator = andAdvance;
      ensureAssignable(expression);
      expression = new AssignmentExpression.full(expression, operator, parseExpressionWithoutCascade());
    }
    return expression;
  }
  /**
   * Parse a class declaration.
   * <pre>
   * classDeclaration ::=
   * metadata 'abstract'? 'class' name typeParameterList? (extendsClause withClause?)? implementsClause? '{' classMembers '}'
   * </pre>
   * @param commentAndMetadata the metadata to be associated with the member
   * @param abstractKeyword the token for the keyword 'abstract', or {@code null} if the keyword was
   * not given
   * @return the class declaration that was parsed
   */
  ClassDeclaration parseClassDeclaration(CommentAndMetadata commentAndMetadata, Token abstractKeyword) {
    Token keyword = expect(Keyword.CLASS);
    SimpleIdentifier name = parseSimpleIdentifier();
    String className = name.name;
    TypeParameterList typeParameters = null;
    if (matches5(TokenType.LT)) {
      typeParameters = parseTypeParameterList();
    }
    ExtendsClause extendsClause = null;
    WithClause withClause = null;
    ImplementsClause implementsClause = null;
    bool foundClause = true;
    while (foundClause) {
      if (matches(Keyword.EXTENDS)) {
        if (extendsClause == null) {
          extendsClause = parseExtendsClause();
          if (withClause != null) {
            reportError5(ParserErrorCode.WITH_BEFORE_EXTENDS, withClause.withKeyword, []);
          } else if (implementsClause != null) {
            reportError5(ParserErrorCode.IMPLEMENTS_BEFORE_EXTENDS, implementsClause.keyword, []);
          }
        } else {
          reportError5(ParserErrorCode.MULTIPLE_EXTENDS_CLAUSES, extendsClause.keyword, []);
          parseExtendsClause();
        }
      } else if (matches(Keyword.WITH)) {
        if (withClause == null) {
          withClause = parseWithClause();
          if (implementsClause != null) {
            reportError5(ParserErrorCode.IMPLEMENTS_BEFORE_WITH, implementsClause.keyword, []);
          }
        } else {
          reportError5(ParserErrorCode.MULTIPLE_WITH_CLAUSES, withClause.withKeyword, []);
          parseWithClause();
        }
      } else if (matches(Keyword.IMPLEMENTS)) {
        if (implementsClause == null) {
          implementsClause = parseImplementsClause();
        } else {
          reportError5(ParserErrorCode.MULTIPLE_IMPLEMENTS_CLAUSES, implementsClause.keyword, []);
          parseImplementsClause();
        }
      } else {
        foundClause = false;
      }
    }
    if (withClause != null && extendsClause == null) {
      reportError5(ParserErrorCode.WITH_WITHOUT_EXTENDS, withClause.withKeyword, []);
    }
    if (matches2(_NATIVE) && matches4(peek(), TokenType.STRING)) {
      advance();
      advance();
    }
    Token leftBracket = null;
    List<ClassMember> members = null;
    Token rightBracket = null;
    if (matches5(TokenType.OPEN_CURLY_BRACKET)) {
      leftBracket = expect2(TokenType.OPEN_CURLY_BRACKET);
      members = parseClassMembers(className, ((leftBracket as BeginToken)).endToken != null);
      rightBracket = expect2(TokenType.CLOSE_CURLY_BRACKET);
    } else {
      leftBracket = createSyntheticToken2(TokenType.OPEN_CURLY_BRACKET);
      rightBracket = createSyntheticToken2(TokenType.CLOSE_CURLY_BRACKET);
      reportError4(ParserErrorCode.MISSING_CLASS_BODY, []);
    }
    return new ClassDeclaration.full(commentAndMetadata.comment, commentAndMetadata.metadata, abstractKeyword, keyword, name, typeParameters, extendsClause, withClause, implementsClause, leftBracket, members, rightBracket);
  }
  /**
   * Parse a class member.
   * <pre>
   * classMemberDefinition ::=
   * declaration ';'
   * | methodSignature functionBody
   * </pre>
   * @param className the name of the class containing the member being parsed
   * @return the class member that was parsed
   */
  ClassMember parseClassMember(String className) {
    CommentAndMetadata commentAndMetadata = parseCommentAndMetadata();
    Modifiers modifiers = parseModifiers();
    if (matches(Keyword.VOID)) {
      TypeName returnType = parseReturnType();
      if (matches(Keyword.GET) && matchesIdentifier2(peek())) {
        validateModifiersForGetterOrSetterOrMethod(modifiers);
        return parseGetter(commentAndMetadata, modifiers.externalKeyword, modifiers.staticKeyword, returnType);
      } else if (matches(Keyword.SET) && matchesIdentifier2(peek())) {
        validateModifiersForGetterOrSetterOrMethod(modifiers);
        return parseSetter(commentAndMetadata, modifiers.externalKeyword, modifiers.staticKeyword, returnType);
      } else if (matches(Keyword.OPERATOR) && isOperator(peek())) {
        validateModifiersForOperator(modifiers);
        return parseOperator(commentAndMetadata, modifiers.externalKeyword, returnType);
      } else if (matchesIdentifier() && matchesAny(peek(), [TokenType.OPEN_PAREN, TokenType.OPEN_CURLY_BRACKET, TokenType.FUNCTION])) {
        validateModifiersForGetterOrSetterOrMethod(modifiers);
        return parseMethodDeclaration(commentAndMetadata, modifiers.externalKeyword, modifiers.staticKeyword, returnType);
      } else {
        if (matchesIdentifier()) {
          if (matchesAny(peek(), [TokenType.EQ, TokenType.COMMA, TokenType.SEMICOLON])) {
            reportError(ParserErrorCode.VOID_VARIABLE, returnType, []);
            return parseInitializedIdentifierList(commentAndMetadata, modifiers.staticKeyword, validateModifiersForField(modifiers), returnType);
          }
        }
        if (isOperator(peek())) {
          validateModifiersForOperator(modifiers);
          return parseOperator(commentAndMetadata, modifiers.externalKeyword, returnType);
        }
        reportError5(ParserErrorCode.EXPECTED_EXECUTABLE, _currentToken, []);
        return null;
      }
    } else if (matches(Keyword.GET) && matchesIdentifier2(peek())) {
      validateModifiersForGetterOrSetterOrMethod(modifiers);
      return parseGetter(commentAndMetadata, modifiers.externalKeyword, modifiers.staticKeyword, null);
    } else if (matches(Keyword.SET) && matchesIdentifier2(peek())) {
      validateModifiersForGetterOrSetterOrMethod(modifiers);
      return parseSetter(commentAndMetadata, modifiers.externalKeyword, modifiers.staticKeyword, null);
    } else if (matches(Keyword.OPERATOR) && isOperator(peek())) {
      validateModifiersForOperator(modifiers);
      return parseOperator(commentAndMetadata, modifiers.externalKeyword, null);
    } else if (!matchesIdentifier()) {
      if (isOperator(peek())) {
        validateModifiersForOperator(modifiers);
        return parseOperator(commentAndMetadata, modifiers.externalKeyword, null);
      }
      reportError5(ParserErrorCode.EXPECTED_CLASS_MEMBER, _currentToken, []);
      return null;
    } else if (matches4(peek(), TokenType.PERIOD) && matchesIdentifier2(peek2(2)) && matches4(peek2(3), TokenType.OPEN_PAREN)) {
      return parseConstructor(commentAndMetadata, modifiers.externalKeyword, validateModifiersForConstructor(modifiers), modifiers.factoryKeyword, parseSimpleIdentifier(), andAdvance, parseSimpleIdentifier(), parseFormalParameterList());
    } else if (matches4(peek(), TokenType.OPEN_PAREN)) {
      SimpleIdentifier methodName = parseSimpleIdentifier();
      FormalParameterList parameters = parseFormalParameterList();
      if (matches5(TokenType.COLON) || modifiers.factoryKeyword != null || methodName.name == className) {
        return parseConstructor(commentAndMetadata, modifiers.externalKeyword, validateModifiersForConstructor(modifiers), modifiers.factoryKeyword, methodName, null, null, parameters);
      }
      validateModifiersForGetterOrSetterOrMethod(modifiers);
      validateFormalParameterList(parameters);
      return parseMethodDeclaration2(commentAndMetadata, modifiers.externalKeyword, modifiers.staticKeyword, null, methodName, parameters);
    } else if (matchesAny(peek(), [TokenType.EQ, TokenType.COMMA, TokenType.SEMICOLON])) {
      return parseInitializedIdentifierList(commentAndMetadata, modifiers.staticKeyword, validateModifiersForField(modifiers), null);
    }
    TypeName type = parseTypeName();
    if (matches(Keyword.GET) && matchesIdentifier2(peek())) {
      validateModifiersForGetterOrSetterOrMethod(modifiers);
      return parseGetter(commentAndMetadata, modifiers.externalKeyword, modifiers.staticKeyword, type);
    } else if (matches(Keyword.SET) && matchesIdentifier2(peek())) {
      validateModifiersForGetterOrSetterOrMethod(modifiers);
      return parseSetter(commentAndMetadata, modifiers.externalKeyword, modifiers.staticKeyword, type);
    } else if (matches(Keyword.OPERATOR) && isOperator(peek())) {
      validateModifiersForOperator(modifiers);
      return parseOperator(commentAndMetadata, modifiers.externalKeyword, type);
    } else if (!matchesIdentifier()) {
      if (matches5(TokenType.CLOSE_CURLY_BRACKET)) {
        return parseInitializedIdentifierList(commentAndMetadata, modifiers.staticKeyword, validateModifiersForField(modifiers), type);
      }
      if (isOperator(peek())) {
        validateModifiersForOperator(modifiers);
        return parseOperator(commentAndMetadata, modifiers.externalKeyword, type);
      }
      reportError5(ParserErrorCode.EXPECTED_CLASS_MEMBER, _currentToken, []);
      return null;
    } else if (matches4(peek(), TokenType.OPEN_PAREN)) {
      validateModifiersForGetterOrSetterOrMethod(modifiers);
      return parseMethodDeclaration(commentAndMetadata, modifiers.externalKeyword, modifiers.staticKeyword, type);
    }
    return parseInitializedIdentifierList(commentAndMetadata, modifiers.staticKeyword, validateModifiersForField(modifiers), type);
  }
  /**
   * Parse a list of class members.
   * <pre>
   * classMembers ::=
   * (metadata memberDefinition)
   * </pre>
   * @param className the name of the class whose members are being parsed
   * @param balancedBrackets {@code true} if the opening and closing brackets for the class are
   * balanced
   * @return the list of class members that were parsed
   */
  List<ClassMember> parseClassMembers(String className, bool balancedBrackets) {
    List<ClassMember> members = new List<ClassMember>();
    Token memberStart = _currentToken;
    while (!matches5(TokenType.EOF) && !matches5(TokenType.CLOSE_CURLY_BRACKET) && (balancedBrackets || (!matches(Keyword.CLASS) && !matches(Keyword.TYPEDEF)))) {
      if (matches5(TokenType.SEMICOLON)) {
        reportError5(ParserErrorCode.UNEXPECTED_TOKEN, _currentToken, [_currentToken.lexeme]);
        advance();
      } else {
        ClassMember member = parseClassMember(className);
        if (member != null) {
          members.add(member);
        }
      }
      if (identical(_currentToken, memberStart)) {
        reportError5(ParserErrorCode.UNEXPECTED_TOKEN, _currentToken, [_currentToken.lexeme]);
        advance();
      }
      memberStart = _currentToken;
    }
    return members;
  }
  /**
   * Parse a class type alias.
   * <pre>
   * classTypeAlias ::=
   * identifier typeParameters? '=' 'abstract'? mixinApplication
   * mixinApplication ::=
   * type withClause implementsClause? ';'
   * </pre>
   * @param commentAndMetadata the metadata to be associated with the member
   * @param keyword the token representing the 'typedef' keyword
   * @return the class type alias that was parsed
   */
  ClassTypeAlias parseClassTypeAlias(CommentAndMetadata commentAndMetadata, Token keyword) {
    SimpleIdentifier name = parseSimpleIdentifier();
    TypeParameterList typeParameters = null;
    if (matches5(TokenType.LT)) {
      typeParameters = parseTypeParameterList();
    }
    Token equals = expect2(TokenType.EQ);
    Token abstractKeyword = null;
    if (matches(Keyword.ABSTRACT)) {
      abstractKeyword = andAdvance;
    }
    TypeName superclass = parseTypeName();
    WithClause withClause = null;
    if (matches(Keyword.WITH)) {
      withClause = parseWithClause();
    }
    ImplementsClause implementsClause = null;
    if (matches(Keyword.IMPLEMENTS)) {
      implementsClause = parseImplementsClause();
    }
    Token semicolon = expect2(TokenType.SEMICOLON);
    return new ClassTypeAlias.full(commentAndMetadata.comment, commentAndMetadata.metadata, keyword, name, typeParameters, equals, abstractKeyword, superclass, withClause, implementsClause, semicolon);
  }
  /**
   * Parse a list of combinators in a directive.
   * <pre>
   * combinator ::=
   * 'show' identifier (',' identifier)
   * | 'hide' identifier (',' identifier)
   * </pre>
   * @return the combinators that were parsed
   */
  List<Combinator> parseCombinators() {
    List<Combinator> combinators = new List<Combinator>();
    while (matches2(_SHOW) || matches2(_HIDE)) {
      Token keyword = expect2(TokenType.IDENTIFIER);
      if (keyword.lexeme == _SHOW) {
        List<SimpleIdentifier> shownNames = parseIdentifierList();
        combinators.add(new ShowCombinator.full(keyword, shownNames));
      } else {
        List<SimpleIdentifier> hiddenNames = parseIdentifierList();
        combinators.add(new HideCombinator.full(keyword, hiddenNames));
      }
    }
    return combinators;
  }
  /**
   * Parse the documentation comment and metadata preceeding a declaration. This method allows any
   * number of documentation comments to occur before, after or between the metadata, but only
   * returns the last (right-most) documentation comment that is found.
   * <pre>
   * metadata ::=
   * annotation
   * </pre>
   * @return the documentation comment and metadata that were parsed
   */
  CommentAndMetadata parseCommentAndMetadata() {
    Comment comment = parseDocumentationComment();
    List<Annotation> metadata = new List<Annotation>();
    while (matches5(TokenType.AT)) {
      metadata.add(parseAnnotation());
      Comment optionalComment = parseDocumentationComment();
      if (optionalComment != null) {
        comment = optionalComment;
      }
    }
    return new CommentAndMetadata(comment, metadata);
  }
  /**
   * Parse a comment reference from the source between square brackets.
   * <pre>
   * commentReference ::=
   * 'new'? prefixedIdentifier
   * </pre>
   * @param referenceSource the source occurring between the square brackets within a documentation
   * comment
   * @param sourceOffset the offset of the first character of the reference source
   * @return the comment reference that was parsed
   */
  CommentReference parseCommentReference(String referenceSource, int sourceOffset) {
    if (referenceSource.length == 0) {
      return null;
    }
    try {
      List<bool> errorFound = [false];
      AnalysisErrorListener listener = new AnalysisErrorListener_12(errorFound);
      StringScanner scanner = new StringScanner(null, referenceSource, listener);
      scanner.setSourceStart(1, 1, sourceOffset);
      Token firstToken = scanner.tokenize();
      if (errorFound[0]) {
        return null;
      }
      Token newKeyword = null;
      if (matches3(firstToken, Keyword.NEW)) {
        newKeyword = firstToken;
        firstToken = firstToken.next;
      }
      if (matchesIdentifier2(firstToken)) {
        Token secondToken = firstToken.next;
        Token thirdToken = secondToken.next;
        Token nextToken;
        Identifier identifier;
        if (matches4(secondToken, TokenType.PERIOD) && matchesIdentifier2(thirdToken)) {
          identifier = new PrefixedIdentifier.full(new SimpleIdentifier.full(firstToken), secondToken, new SimpleIdentifier.full(thirdToken));
          nextToken = thirdToken.next;
        } else {
          identifier = new SimpleIdentifier.full(firstToken);
          nextToken = firstToken.next;
        }
        if (nextToken.type != TokenType.EOF) {
          return null;
        }
        return new CommentReference.full(newKeyword, identifier);
      } else if (matches3(firstToken, Keyword.THIS) || matches3(firstToken, Keyword.NULL) || matches3(firstToken, Keyword.TRUE) || matches3(firstToken, Keyword.FALSE)) {
        return null;
      }
    } catch (exception) {
    }
    return null;
  }
  /**
   * Parse all of the comment references occurring in the given array of documentation comments.
   * <pre>
   * commentReference ::=
   * '\[' 'new'? qualified '\]' libraryReference?
   * libraryReference ::=
   * '(' stringLiteral ')'
   * </pre>
   * @param tokens the comment tokens representing the documentation comments to be parsed
   * @return the comment references that were parsed
   */
  List<CommentReference> parseCommentReferences(List<Token> tokens) {
    List<CommentReference> references = new List<CommentReference>();
    for (Token token in tokens) {
      String comment = token.lexeme;
      int length2 = comment.length;
      List<List<int>> codeBlockRanges = getCodeBlockRanges(comment);
      int leftIndex = comment.indexOf('[');
      while (leftIndex >= 0 && leftIndex + 1 < length2) {
        List<int> range = findRange(codeBlockRanges, leftIndex);
        if (range == null) {
          int rightIndex = comment.indexOf(']', leftIndex);
          if (rightIndex >= 0) {
            int firstChar = comment.codeUnitAt(leftIndex + 1);
            if (firstChar != 0x27 && firstChar != 0x22) {
              if (isLinkText(comment, rightIndex)) {
              } else {
                CommentReference reference = parseCommentReference(comment.substring(leftIndex + 1, rightIndex), token.offset + leftIndex + 1);
                if (reference != null) {
                  references.add(reference);
                }
              }
            }
          } else {
            rightIndex = leftIndex + 1;
          }
          leftIndex = comment.indexOf('[', rightIndex);
        } else {
          leftIndex = comment.indexOf('[', range[1] + 1);
        }
      }
    }
    return references;
  }
  /**
   * Parse a compilation unit.
   * <p>
   * Specified:
   * <pre>
   * compilationUnit ::=
   * scriptTag? directive* topLevelDeclaration
   * </pre>
   * Actual:
   * <pre>
   * compilationUnit ::=
   * scriptTag? topLevelElement
   * topLevelElement ::=
   * directive
   * | topLevelDeclaration
   * </pre>
   * @return the compilation unit that was parsed
   */
  CompilationUnit parseCompilationUnit2() {
    Token firstToken = _currentToken;
    ScriptTag scriptTag = null;
    if (matches5(TokenType.SCRIPT_TAG)) {
      scriptTag = new ScriptTag.full(andAdvance);
    }
    bool libraryDirectiveFound = false;
    bool partOfDirectiveFound = false;
    bool partDirectiveFound = false;
    bool directiveFoundAfterDeclaration = false;
    List<Directive> directives = new List<Directive>();
    List<CompilationUnitMember> declarations = new List<CompilationUnitMember>();
    Token memberStart = _currentToken;
    while (!matches5(TokenType.EOF)) {
      CommentAndMetadata commentAndMetadata = parseCommentAndMetadata();
      if ((matches(Keyword.IMPORT) || matches(Keyword.EXPORT) || matches(Keyword.LIBRARY) || matches(Keyword.PART)) && !matches4(peek(), TokenType.PERIOD) && !matches4(peek(), TokenType.LT)) {
        Directive directive = parseDirective(commentAndMetadata);
        if (declarations.length > 0 && !directiveFoundAfterDeclaration) {
          reportError4(ParserErrorCode.DIRECTIVE_AFTER_DECLARATION, []);
          directiveFoundAfterDeclaration = true;
        }
        if (directive is LibraryDirective) {
          if (libraryDirectiveFound) {
            reportError4(ParserErrorCode.MULTIPLE_LIBRARY_DIRECTIVES, []);
          } else {
            if (directives.length > 0) {
              reportError4(ParserErrorCode.LIBRARY_DIRECTIVE_NOT_FIRST, []);
            }
            libraryDirectiveFound = true;
          }
        } else if (directive is PartDirective) {
          partDirectiveFound = true;
        } else if (partDirectiveFound) {
          if (directive is ExportDirective) {
            reportError4(ParserErrorCode.EXPORT_DIRECTIVE_AFTER_PART_DIRECTIVE, []);
          } else if (directive is ImportDirective) {
            reportError4(ParserErrorCode.IMPORT_DIRECTIVE_AFTER_PART_DIRECTIVE, []);
          }
        }
        if (directive is PartOfDirective) {
          if (partOfDirectiveFound) {
            reportError4(ParserErrorCode.MULTIPLE_PART_OF_DIRECTIVES, []);
          } else {
            for (Directive preceedingDirective in directives) {
              reportError5(ParserErrorCode.NON_PART_OF_DIRECTIVE_IN_PART, preceedingDirective.keyword, []);
            }
            partOfDirectiveFound = true;
          }
        } else {
          if (partOfDirectiveFound) {
            reportError5(ParserErrorCode.NON_PART_OF_DIRECTIVE_IN_PART, directive.keyword, []);
          }
        }
        directives.add(directive);
      } else if (matches5(TokenType.SEMICOLON)) {
        reportError5(ParserErrorCode.UNEXPECTED_TOKEN, _currentToken, [_currentToken.lexeme]);
        advance();
      } else {
        CompilationUnitMember member = parseCompilationUnitMember(commentAndMetadata);
        if (member != null) {
          declarations.add(member);
        }
      }
      if (identical(_currentToken, memberStart)) {
        reportError5(ParserErrorCode.UNEXPECTED_TOKEN, _currentToken, [_currentToken.lexeme]);
        advance();
      }
      memberStart = _currentToken;
    }
    return new CompilationUnit.full(firstToken, scriptTag, directives, declarations, _currentToken);
  }
  /**
   * Parse a compilation unit member.
   * <pre>
   * compilationUnitMember ::=
   * classDefinition
   * | functionTypeAlias
   * | external functionSignature
   * | external getterSignature
   * | external setterSignature
   * | functionSignature functionBody
   * | returnType? getOrSet identifier formalParameterList functionBody
   * | (final | const) type? staticFinalDeclarationList ';'
   * | variableDeclaration ';'
   * </pre>
   * @param commentAndMetadata the metadata to be associated with the member
   * @return the compilation unit member that was parsed
   */
  CompilationUnitMember parseCompilationUnitMember(CommentAndMetadata commentAndMetadata) {
    Modifiers modifiers = parseModifiers();
    if (matches(Keyword.CLASS)) {
      return parseClassDeclaration(commentAndMetadata, validateModifiersForClass(modifiers));
    } else if (matches(Keyword.TYPEDEF) && !matches4(peek(), TokenType.PERIOD) && !matches4(peek(), TokenType.LT)) {
      validateModifiersForTypedef(modifiers);
      return parseTypeAlias(commentAndMetadata);
    }
    if (matches(Keyword.VOID)) {
      TypeName returnType = parseReturnType();
      if ((matches(Keyword.GET) || matches(Keyword.SET)) && matchesIdentifier2(peek())) {
        validateModifiersForTopLevelFunction(modifiers);
        return parseFunctionDeclaration(commentAndMetadata, modifiers.externalKeyword, null);
      } else if (matches(Keyword.OPERATOR) && isOperator(peek())) {
        reportError5(ParserErrorCode.TOP_LEVEL_OPERATOR, _currentToken, []);
        return null;
      } else if (matchesIdentifier() && matchesAny(peek(), [TokenType.OPEN_PAREN, TokenType.OPEN_CURLY_BRACKET, TokenType.FUNCTION])) {
        validateModifiersForTopLevelFunction(modifiers);
        return parseFunctionDeclaration(commentAndMetadata, modifiers.externalKeyword, returnType);
      } else {
        if (matchesIdentifier()) {
          if (matchesAny(peek(), [TokenType.EQ, TokenType.COMMA, TokenType.SEMICOLON])) {
            reportError(ParserErrorCode.VOID_VARIABLE, returnType, []);
            return new TopLevelVariableDeclaration.full(commentAndMetadata.comment, commentAndMetadata.metadata, parseVariableDeclarationList2(null, validateModifiersForTopLevelVariable(modifiers), null), expect2(TokenType.SEMICOLON));
          }
        }
        reportError5(ParserErrorCode.EXPECTED_EXECUTABLE, _currentToken, []);
        return null;
      }
    } else if ((matches(Keyword.GET) || matches(Keyword.SET)) && matchesIdentifier2(peek())) {
      validateModifiersForTopLevelFunction(modifiers);
      return parseFunctionDeclaration(commentAndMetadata, modifiers.externalKeyword, null);
    } else if (matches(Keyword.OPERATOR) && isOperator(peek())) {
      reportError5(ParserErrorCode.TOP_LEVEL_OPERATOR, _currentToken, []);
      return null;
    } else if (!matchesIdentifier()) {
      reportError5(ParserErrorCode.EXPECTED_EXECUTABLE, _currentToken, []);
      return null;
    } else if (matches4(peek(), TokenType.OPEN_PAREN)) {
      validateModifiersForTopLevelFunction(modifiers);
      return parseFunctionDeclaration(commentAndMetadata, modifiers.externalKeyword, null);
    } else if (matchesAny(peek(), [TokenType.EQ, TokenType.COMMA, TokenType.SEMICOLON])) {
      return new TopLevelVariableDeclaration.full(commentAndMetadata.comment, commentAndMetadata.metadata, parseVariableDeclarationList2(null, validateModifiersForTopLevelVariable(modifiers), null), expect2(TokenType.SEMICOLON));
    }
    TypeName returnType = parseReturnType();
    if (matches(Keyword.GET) || matches(Keyword.SET)) {
      validateModifiersForTopLevelFunction(modifiers);
      return parseFunctionDeclaration(commentAndMetadata, modifiers.externalKeyword, returnType);
    } else if (matches(Keyword.OPERATOR) && isOperator(peek())) {
      reportError5(ParserErrorCode.TOP_LEVEL_OPERATOR, _currentToken, []);
      return null;
    } else if (!matchesIdentifier()) {
      reportError5(ParserErrorCode.EXPECTED_EXECUTABLE, _currentToken, []);
      return null;
    }
    if (matchesAny(peek(), [TokenType.OPEN_PAREN, TokenType.FUNCTION, TokenType.OPEN_CURLY_BRACKET])) {
      validateModifiersForTopLevelFunction(modifiers);
      return parseFunctionDeclaration(commentAndMetadata, modifiers.externalKeyword, returnType);
    }
    return new TopLevelVariableDeclaration.full(commentAndMetadata.comment, commentAndMetadata.metadata, parseVariableDeclarationList2(null, validateModifiersForTopLevelVariable(modifiers), returnType), expect2(TokenType.SEMICOLON));
  }
  /**
   * Parse a conditional expression.
   * <pre>
   * conditionalExpression ::=
   * logicalOrExpression ('?' expressionWithoutCascade ':' expressionWithoutCascade)?
   * </pre>
   * @return the conditional expression that was parsed
   */
  Expression parseConditionalExpression() {
    Expression condition = parseLogicalOrExpression();
    if (!matches5(TokenType.QUESTION)) {
      return condition;
    }
    Token question = andAdvance;
    Expression thenExpression = parseExpressionWithoutCascade();
    Token colon = expect2(TokenType.COLON);
    Expression elseExpression = parseExpressionWithoutCascade();
    return new ConditionalExpression.full(condition, question, thenExpression, colon, elseExpression);
  }
  /**
   * Parse a const expression.
   * <pre>
   * constExpression ::=
   * instanceCreationExpression
   * | listLiteral
   * | mapLiteral
   * </pre>
   * @return the const expression that was parsed
   */
  Expression parseConstExpression() {
    Token keyword = expect(Keyword.CONST);
    if (matches5(TokenType.OPEN_SQUARE_BRACKET) || matches5(TokenType.INDEX)) {
      return parseListLiteral(keyword, null);
    } else if (matches5(TokenType.OPEN_CURLY_BRACKET)) {
      return parseMapLiteral(keyword, null);
    } else if (matches5(TokenType.LT)) {
      return parseListOrMapLiteral(keyword);
    }
    return parseInstanceCreationExpression(keyword);
  }
  ConstructorDeclaration parseConstructor(CommentAndMetadata commentAndMetadata, Token externalKeyword, Token constKeyword, Token factoryKeyword, SimpleIdentifier returnType, Token period, SimpleIdentifier name, FormalParameterList parameters) {
    bool bodyAllowed = externalKeyword == null;
    Token separator = null;
    List<ConstructorInitializer> initializers = null;
    if (matches5(TokenType.COLON)) {
      separator = andAdvance;
      initializers = new List<ConstructorInitializer>();
      do {
        if (matches(Keyword.THIS)) {
          if (matches4(peek(), TokenType.OPEN_PAREN)) {
            bodyAllowed = false;
            initializers.add(parseRedirectingConstructorInvocation());
          } else if (matches4(peek(), TokenType.PERIOD) && matches4(peek2(3), TokenType.OPEN_PAREN)) {
            bodyAllowed = false;
            initializers.add(parseRedirectingConstructorInvocation());
          } else {
            initializers.add(parseConstructorFieldInitializer());
          }
        } else if (matches(Keyword.SUPER)) {
          initializers.add(parseSuperConstructorInvocation());
        } else {
          initializers.add(parseConstructorFieldInitializer());
        }
      } while (optional(TokenType.COMMA));
    }
    ConstructorName redirectedConstructor = null;
    FunctionBody body;
    if (matches5(TokenType.EQ)) {
      separator = andAdvance;
      redirectedConstructor = parseConstructorName();
      body = new EmptyFunctionBody.full(expect2(TokenType.SEMICOLON));
    } else {
      body = parseFunctionBody(true, false);
      if (!bodyAllowed && body is! EmptyFunctionBody) {
        reportError4(ParserErrorCode.EXTERNAL_CONSTRUCTOR_WITH_BODY, []);
      }
    }
    return new ConstructorDeclaration.full(commentAndMetadata.comment, commentAndMetadata.metadata, externalKeyword, constKeyword, factoryKeyword, returnType, period, name, parameters, separator, initializers, redirectedConstructor, body);
  }
  /**
   * Parse a field initializer within a constructor.
   * <pre>
   * fieldInitializer:
   * ('this' '.')? identifier '=' conditionalExpression cascadeSection
   * </pre>
   * @return the field initializer that was parsed
   */
  ConstructorFieldInitializer parseConstructorFieldInitializer() {
    Token keyword = null;
    Token period = null;
    if (matches(Keyword.THIS)) {
      keyword = andAdvance;
      period = expect2(TokenType.PERIOD);
    }
    SimpleIdentifier fieldName = parseSimpleIdentifier();
    Token equals = expect2(TokenType.EQ);
    Expression expression = parseConditionalExpression();
    TokenType tokenType = _currentToken.type;
    if (identical(tokenType, TokenType.PERIOD_PERIOD)) {
      List<Expression> cascadeSections = new List<Expression>();
      while (identical(tokenType, TokenType.PERIOD_PERIOD)) {
        Expression section = parseCascadeSection();
        if (section != null) {
          cascadeSections.add(section);
        }
        tokenType = _currentToken.type;
      }
      expression = new CascadeExpression.full(expression, cascadeSections);
    }
    return new ConstructorFieldInitializer.full(keyword, period, fieldName, equals, expression);
  }
  /**
   * Parse the name of a constructor.
   * <pre>
   * constructorName:
   * type ('.' identifier)?
   * </pre>
   * @return the constructor name that was parsed
   */
  ConstructorName parseConstructorName() {
    TypeName type = parseTypeName();
    Token period = null;
    SimpleIdentifier name = null;
    if (matches5(TokenType.PERIOD)) {
      period = andAdvance;
      name = parseSimpleIdentifier();
    }
    return new ConstructorName.full(type, period, name);
  }
  /**
   * Parse a continue statement.
   * <pre>
   * continueStatement ::=
   * 'continue' identifier? ';'
   * </pre>
   * @return the continue statement that was parsed
   */
  Statement parseContinueStatement() {
    Token continueKeyword = expect(Keyword.CONTINUE);
    if (!_inLoop && !_inSwitch) {
      reportError5(ParserErrorCode.CONTINUE_OUTSIDE_OF_LOOP, continueKeyword, []);
    }
    SimpleIdentifier label = null;
    if (matchesIdentifier()) {
      label = parseSimpleIdentifier();
    }
    if (_inSwitch && !_inLoop && label == null) {
      reportError5(ParserErrorCode.CONTINUE_WITHOUT_LABEL_IN_CASE, continueKeyword, []);
    }
    Token semicolon = expect2(TokenType.SEMICOLON);
    return new ContinueStatement.full(continueKeyword, label, semicolon);
  }
  /**
   * Parse a directive.
   * <pre>
   * directive ::=
   * exportDirective
   * | libraryDirective
   * | importDirective
   * | partDirective
   * </pre>
   * @param commentAndMetadata the metadata to be associated with the directive
   * @return the directive that was parsed
   */
  Directive parseDirective(CommentAndMetadata commentAndMetadata) {
    if (matches(Keyword.IMPORT)) {
      return parseImportDirective(commentAndMetadata);
    } else if (matches(Keyword.EXPORT)) {
      return parseExportDirective(commentAndMetadata);
    } else if (matches(Keyword.LIBRARY)) {
      return parseLibraryDirective(commentAndMetadata);
    } else if (matches(Keyword.PART)) {
      return parsePartDirective(commentAndMetadata);
    } else {
      return null;
    }
  }
  /**
   * Parse a documentation comment.
   * <pre>
   * documentationComment ::=
   * multiLineComment?
   * | singleLineComment
   * </pre>
   * @return the documentation comment that was parsed, or {@code null} if there was no comment
   */
  Comment parseDocumentationComment() {
    List<Token> commentTokens = new List<Token>();
    Token commentToken = _currentToken.precedingComments;
    while (commentToken != null) {
      if (identical(commentToken.type, TokenType.SINGLE_LINE_COMMENT)) {
        if (commentToken.lexeme.startsWith("///")) {
          if (commentTokens.length == 1 && commentTokens[0].lexeme.startsWith("/**")) {
            commentTokens.clear();
          }
          commentTokens.add(commentToken);
        }
      } else {
        if (commentToken.lexeme.startsWith("/**")) {
          commentTokens.clear();
          commentTokens.add(commentToken);
        }
      }
      commentToken = commentToken.next;
    }
    if (commentTokens.isEmpty) {
      return null;
    }
    List<Token> tokens = new List.from(commentTokens);
    List<CommentReference> references = parseCommentReferences(tokens);
    return Comment.createDocumentationComment2(tokens, references);
  }
  /**
   * Parse a do statement.
   * <pre>
   * doStatement ::=
   * 'do' statement 'while' '(' expression ')' ';'
   * </pre>
   * @return the do statement that was parsed
   */
  Statement parseDoStatement() {
    bool wasInLoop = _inLoop;
    _inLoop = true;
    try {
      Token doKeyword = expect(Keyword.DO);
      Statement body = parseStatement2();
      Token whileKeyword = expect(Keyword.WHILE);
      Token leftParenthesis = expect2(TokenType.OPEN_PAREN);
      Expression condition = parseExpression2();
      Token rightParenthesis = expect2(TokenType.CLOSE_PAREN);
      Token semicolon = expect2(TokenType.SEMICOLON);
      return new DoStatement.full(doKeyword, body, whileKeyword, leftParenthesis, condition, rightParenthesis, semicolon);
    } finally {
      _inLoop = wasInLoop;
    }
  }
  /**
   * Parse an empty statement.
   * <pre>
   * emptyStatement ::=
   * ';'
   * </pre>
   * @return the empty statement that was parsed
   */
  Statement parseEmptyStatement() => new EmptyStatement.full(andAdvance);
  /**
   * Parse an equality expression.
   * <pre>
   * equalityExpression ::=
   * relationalExpression (equalityOperator relationalExpression)?
   * | 'super' equalityOperator relationalExpression
   * </pre>
   * @return the equality expression that was parsed
   */
  Expression parseEqualityExpression() {
    Expression expression;
    if (matches(Keyword.SUPER) && _currentToken.next.type.isEqualityOperator()) {
      expression = new SuperExpression.full(andAdvance);
    } else {
      expression = parseRelationalExpression();
    }
    while (_currentToken.type.isEqualityOperator()) {
      Token operator = andAdvance;
      expression = new BinaryExpression.full(expression, operator, parseRelationalExpression());
    }
    return expression;
  }
  /**
   * Parse an export directive.
   * <pre>
   * exportDirective ::=
   * metadata 'export' stringLiteral combinator*';'
   * </pre>
   * @param commentAndMetadata the metadata to be associated with the directive
   * @return the export directive that was parsed
   */
  ExportDirective parseExportDirective(CommentAndMetadata commentAndMetadata) {
    Token exportKeyword = expect(Keyword.EXPORT);
    StringLiteral libraryUri = parseStringLiteral();
    List<Combinator> combinators = parseCombinators();
    Token semicolon = expect2(TokenType.SEMICOLON);
    return new ExportDirective.full(commentAndMetadata.comment, commentAndMetadata.metadata, exportKeyword, libraryUri, combinators, semicolon);
  }
  /**
   * Parse an expression that does not contain any cascades.
   * <pre>
   * expression ::=
   * assignableExpression assignmentOperator expression
   * | conditionalExpression cascadeSection
   * | throwExpression
   * </pre>
   * @return the expression that was parsed
   */
  Expression parseExpression2() {
    if (matches(Keyword.THROW)) {
      return parseThrowExpression();
    } else if (matches(Keyword.RETHROW)) {
      return parseRethrowExpression();
    }
    Expression expression = parseConditionalExpression();
    TokenType tokenType = _currentToken.type;
    if (identical(tokenType, TokenType.PERIOD_PERIOD)) {
      List<Expression> cascadeSections = new List<Expression>();
      while (identical(tokenType, TokenType.PERIOD_PERIOD)) {
        Expression section = parseCascadeSection();
        if (section != null) {
          cascadeSections.add(section);
        }
        tokenType = _currentToken.type;
      }
      return new CascadeExpression.full(expression, cascadeSections);
    } else if (tokenType.isAssignmentOperator()) {
      Token operator = andAdvance;
      ensureAssignable(expression);
      return new AssignmentExpression.full(expression, operator, parseExpression2());
    }
    return expression;
  }
  /**
   * Parse a list of expressions.
   * <pre>
   * expressionList ::=
   * expression (',' expression)
   * </pre>
   * @return the expression that was parsed
   */
  List<Expression> parseExpressionList() {
    List<Expression> expressions = new List<Expression>();
    expressions.add(parseExpression2());
    while (optional(TokenType.COMMA)) {
      expressions.add(parseExpression2());
    }
    return expressions;
  }
  /**
   * Parse an expression that does not contain any cascades.
   * <pre>
   * expressionWithoutCascade ::=
   * assignableExpression assignmentOperator expressionWithoutCascade
   * | conditionalExpression
   * | throwExpressionWithoutCascade
   * </pre>
   * @return the expression that was parsed
   */
  Expression parseExpressionWithoutCascade() {
    if (matches(Keyword.THROW)) {
      return parseThrowExpressionWithoutCascade();
    } else if (matches(Keyword.RETHROW)) {
      return parseRethrowExpression();
    }
    Expression expression = parseConditionalExpression();
    if (_currentToken.type.isAssignmentOperator()) {
      Token operator = andAdvance;
      ensureAssignable(expression);
      expression = new AssignmentExpression.full(expression, operator, parseExpressionWithoutCascade());
    }
    return expression;
  }
  /**
   * Parse a class extends clause.
   * <pre>
   * classExtendsClause ::=
   * 'extends' type
   * </pre>
   * @return the class extends clause that was parsed
   */
  ExtendsClause parseExtendsClause() {
    Token keyword = expect(Keyword.EXTENDS);
    TypeName superclass = parseTypeName();
    return new ExtendsClause.full(keyword, superclass);
  }
  /**
   * Parse the 'final', 'const', 'var' or type preceding a variable declaration.
   * <pre>
   * finalConstVarOrType ::=
   * | 'final' type?
   * | 'const' type?
   * | 'var'
   * | type
   * </pre>
   * @param optional {@code true} if the keyword and type are optional
   * @return the 'final', 'const', 'var' or type that was parsed
   */
  FinalConstVarOrType parseFinalConstVarOrType(bool optional) {
    Token keyword = null;
    TypeName type = null;
    if (matches(Keyword.FINAL) || matches(Keyword.CONST)) {
      keyword = andAdvance;
      if (matchesIdentifier2(peek()) || matches4(peek(), TokenType.LT) || matches3(peek(), Keyword.THIS)) {
        type = parseTypeName();
      }
    } else if (matches(Keyword.VAR)) {
      keyword = andAdvance;
    } else {
      if (matchesIdentifier2(peek()) || matches4(peek(), TokenType.LT) || matches3(peek(), Keyword.THIS) || (matches4(peek(), TokenType.PERIOD) && matchesIdentifier2(peek2(2)) && (matchesIdentifier2(peek2(3)) || matches4(peek2(3), TokenType.LT) || matches3(peek2(3), Keyword.THIS)))) {
        type = parseReturnType();
      } else if (!optional) {
        reportError4(ParserErrorCode.MISSING_CONST_FINAL_VAR_OR_TYPE, []);
      }
    }
    return new FinalConstVarOrType(keyword, type);
  }
  /**
   * Parse a formal parameter. At most one of {@code isOptional} and {@code isNamed} can be{@code true}.
   * <pre>
   * defaultFormalParameter ::=
   * normalFormalParameter ('=' expression)?
   * defaultNamedParameter ::=
   * normalFormalParameter (':' expression)?
   * </pre>
   * @param kind the kind of parameter being expected based on the presence or absence of group
   * delimiters
   * @return the formal parameter that was parsed
   */
  FormalParameter parseFormalParameter(ParameterKind kind) {
    NormalFormalParameter parameter = parseNormalFormalParameter();
    if (matches5(TokenType.EQ)) {
      Token seperator = andAdvance;
      Expression defaultValue = parseExpression2();
      if (identical(kind, ParameterKind.NAMED)) {
        reportError5(ParserErrorCode.WRONG_SEPARATOR_FOR_NAMED_PARAMETER, seperator, []);
      } else if (identical(kind, ParameterKind.REQUIRED)) {
        reportError(ParserErrorCode.POSITIONAL_PARAMETER_OUTSIDE_GROUP, parameter, []);
      }
      return new DefaultFormalParameter.full(parameter, kind, seperator, defaultValue);
    } else if (matches5(TokenType.COLON)) {
      Token seperator = andAdvance;
      Expression defaultValue = parseExpression2();
      if (identical(kind, ParameterKind.POSITIONAL)) {
        reportError5(ParserErrorCode.WRONG_SEPARATOR_FOR_POSITIONAL_PARAMETER, seperator, []);
      } else if (identical(kind, ParameterKind.REQUIRED)) {
        reportError(ParserErrorCode.NAMED_PARAMETER_OUTSIDE_GROUP, parameter, []);
      }
      return new DefaultFormalParameter.full(parameter, kind, seperator, defaultValue);
    } else if (kind != ParameterKind.REQUIRED) {
      return new DefaultFormalParameter.full(parameter, kind, null, null);
    }
    return parameter;
  }
  /**
   * Parse a list of formal parameters.
   * <pre>
   * formalParameterList ::=
   * '(' ')'
   * | '(' normalFormalParameters (',' optionalFormalParameters)? ')'
   * | '(' optionalFormalParameters ')'
   * normalFormalParameters ::=
   * normalFormalParameter (',' normalFormalParameter)
   * optionalFormalParameters ::=
   * optionalPositionalFormalParameters
   * | namedFormalParameters
   * optionalPositionalFormalParameters ::=
   * '\[' defaultFormalParameter (',' defaultFormalParameter)* '\]'
   * namedFormalParameters ::=
   * '{' defaultNamedParameter (',' defaultNamedParameter)* '}'
   * </pre>
   * @return the formal parameters that were parsed
   */
  FormalParameterList parseFormalParameterList() {
    Token leftParenthesis = expect2(TokenType.OPEN_PAREN);
    if (matches5(TokenType.CLOSE_PAREN)) {
      return new FormalParameterList.full(leftParenthesis, null, null, null, andAdvance);
    }
    List<FormalParameter> parameters = new List<FormalParameter>();
    List<FormalParameter> normalParameters = new List<FormalParameter>();
    List<FormalParameter> positionalParameters = new List<FormalParameter>();
    List<FormalParameter> namedParameters = new List<FormalParameter>();
    List<FormalParameter> currentParameters = normalParameters;
    Token leftSquareBracket = null;
    Token rightSquareBracket = null;
    Token leftCurlyBracket = null;
    Token rightCurlyBracket = null;
    ParameterKind kind = ParameterKind.REQUIRED;
    bool firstParameter = true;
    bool reportedMuliplePositionalGroups = false;
    bool reportedMulipleNamedGroups = false;
    bool reportedMixedGroups = false;
    Token initialToken = null;
    do {
      if (firstParameter) {
        firstParameter = false;
      } else if (!optional(TokenType.COMMA)) {
        if ((leftParenthesis is BeginToken) && ((leftParenthesis as BeginToken)).endToken != null) {
          reportError4(ParserErrorCode.EXPECTED_TOKEN, [TokenType.COMMA.lexeme]);
        } else {
          reportError5(ParserErrorCode.MISSING_CLOSING_PARENTHESIS, _currentToken.previous, []);
          break;
        }
      }
      initialToken = _currentToken;
      if (matches5(TokenType.OPEN_SQUARE_BRACKET)) {
        if (leftSquareBracket != null && !reportedMuliplePositionalGroups) {
          reportError4(ParserErrorCode.MULTIPLE_POSITIONAL_PARAMETER_GROUPS, []);
          reportedMuliplePositionalGroups = true;
        }
        if (leftCurlyBracket != null && !reportedMixedGroups) {
          reportError4(ParserErrorCode.MIXED_PARAMETER_GROUPS, []);
          reportedMixedGroups = true;
        }
        leftSquareBracket = andAdvance;
        currentParameters = positionalParameters;
        kind = ParameterKind.POSITIONAL;
      } else if (matches5(TokenType.OPEN_CURLY_BRACKET)) {
        if (leftCurlyBracket != null && !reportedMulipleNamedGroups) {
          reportError4(ParserErrorCode.MULTIPLE_NAMED_PARAMETER_GROUPS, []);
          reportedMulipleNamedGroups = true;
        }
        if (leftSquareBracket != null && !reportedMixedGroups) {
          reportError4(ParserErrorCode.MIXED_PARAMETER_GROUPS, []);
          reportedMixedGroups = true;
        }
        leftCurlyBracket = andAdvance;
        currentParameters = namedParameters;
        kind = ParameterKind.NAMED;
      }
      FormalParameter parameter = parseFormalParameter(kind);
      parameters.add(parameter);
      currentParameters.add(parameter);
      if (matches5(TokenType.CLOSE_SQUARE_BRACKET)) {
        rightSquareBracket = andAdvance;
        currentParameters = normalParameters;
        if (leftSquareBracket == null) {
          if (leftCurlyBracket != null) {
            reportError4(ParserErrorCode.WRONG_TERMINATOR_FOR_PARAMETER_GROUP, ["}"]);
            rightCurlyBracket = rightSquareBracket;
            rightSquareBracket = null;
          } else {
            reportError4(ParserErrorCode.UNEXPECTED_TERMINATOR_FOR_PARAMETER_GROUP, ["["]);
          }
        }
        kind = ParameterKind.REQUIRED;
      } else if (matches5(TokenType.CLOSE_CURLY_BRACKET)) {
        rightCurlyBracket = andAdvance;
        currentParameters = normalParameters;
        if (leftCurlyBracket == null) {
          if (leftSquareBracket != null) {
            reportError4(ParserErrorCode.WRONG_TERMINATOR_FOR_PARAMETER_GROUP, ["]"]);
            rightSquareBracket = rightCurlyBracket;
            rightCurlyBracket = null;
          } else {
            reportError4(ParserErrorCode.UNEXPECTED_TERMINATOR_FOR_PARAMETER_GROUP, ["{"]);
          }
        }
        kind = ParameterKind.REQUIRED;
      }
    } while (!matches5(TokenType.CLOSE_PAREN) && initialToken != _currentToken);
    Token rightParenthesis = expect2(TokenType.CLOSE_PAREN);
    if (leftSquareBracket != null && rightSquareBracket == null) {
      reportError4(ParserErrorCode.MISSING_TERMINATOR_FOR_PARAMETER_GROUP, ["]"]);
    }
    if (leftCurlyBracket != null && rightCurlyBracket == null) {
      reportError4(ParserErrorCode.MISSING_TERMINATOR_FOR_PARAMETER_GROUP, ["}"]);
    }
    if (leftSquareBracket == null) {
      leftSquareBracket = leftCurlyBracket;
    }
    if (rightSquareBracket == null) {
      rightSquareBracket = rightCurlyBracket;
    }
    return new FormalParameterList.full(leftParenthesis, parameters, leftSquareBracket, rightSquareBracket, rightParenthesis);
  }
  /**
   * Parse a for statement.
   * <pre>
   * forStatement ::=
   * 'for' '(' forLoopParts ')' statement
   * forLoopParts ::=
   * forInitializerStatement expression? ';' expressionList?
   * | declaredIdentifier 'in' expression
   * | identifier 'in' expression
   * forInitializerStatement ::=
   * localVariableDeclaration ';'
   * | expression? ';'
   * </pre>
   * @return the for statement that was parsed
   */
  Statement parseForStatement() {
    bool wasInLoop = _inLoop;
    _inLoop = true;
    try {
      Token forKeyword = expect(Keyword.FOR);
      Token leftParenthesis = expect2(TokenType.OPEN_PAREN);
      VariableDeclarationList variableList = null;
      Expression initialization = null;
      if (!matches5(TokenType.SEMICOLON)) {
        CommentAndMetadata commentAndMetadata = parseCommentAndMetadata();
        if (matchesIdentifier() && matches3(peek(), Keyword.IN)) {
          List<VariableDeclaration> variables = new List<VariableDeclaration>();
          SimpleIdentifier variableName = parseSimpleIdentifier();
          variables.add(new VariableDeclaration.full(null, null, variableName, null, null));
          variableList = new VariableDeclarationList.full(commentAndMetadata.comment, commentAndMetadata.metadata, null, null, variables);
        } else if (isInitializedVariableDeclaration()) {
          variableList = parseVariableDeclarationList(commentAndMetadata);
        } else {
          initialization = parseExpression2();
        }
        if (matches(Keyword.IN)) {
          DeclaredIdentifier loopVariable = null;
          if (variableList == null) {
            reportError4(ParserErrorCode.MISSING_VARIABLE_IN_FOR_EACH, []);
          } else {
            NodeList<VariableDeclaration> variables2 = variableList.variables;
            if (variables2.length > 1) {
              reportError4(ParserErrorCode.MULTIPLE_VARIABLES_IN_FOR_EACH, [variables2.length.toString()]);
            }
            VariableDeclaration variable = variables2[0];
            if (variable.initializer != null) {
              reportError4(ParserErrorCode.INITIALIZED_VARIABLE_IN_FOR_EACH, []);
            }
            loopVariable = new DeclaredIdentifier.full(commentAndMetadata.comment, commentAndMetadata.metadata, variableList.keyword, variableList.type, variable.name);
          }
          Token inKeyword = expect(Keyword.IN);
          Expression iterator = parseExpression2();
          Token rightParenthesis = expect2(TokenType.CLOSE_PAREN);
          Statement body = parseStatement2();
          return new ForEachStatement.full(forKeyword, leftParenthesis, loopVariable, inKeyword, iterator, rightParenthesis, body);
        }
      }
      Token leftSeparator = expect2(TokenType.SEMICOLON);
      Expression condition = null;
      if (!matches5(TokenType.SEMICOLON)) {
        condition = parseExpression2();
      }
      Token rightSeparator = expect2(TokenType.SEMICOLON);
      List<Expression> updaters = null;
      if (!matches5(TokenType.CLOSE_PAREN)) {
        updaters = parseExpressionList();
      }
      Token rightParenthesis = expect2(TokenType.CLOSE_PAREN);
      Statement body = parseStatement2();
      return new ForStatement.full(forKeyword, leftParenthesis, variableList, initialization, leftSeparator, condition, rightSeparator, updaters, rightParenthesis, body);
    } finally {
      _inLoop = wasInLoop;
    }
  }
  /**
   * Parse a function body.
   * <pre>
   * functionBody ::=
   * '=>' expression ';'
   * | block
   * functionExpressionBody ::=
   * '=>' expression
   * | block
   * </pre>
   * @param mayBeEmpty {@code true} if the function body is allowed to be empty
   * @param inExpression {@code true} if the function body is being parsed as part of an expression
   * and therefore does not have a terminating semicolon
   * @return the function body that was parsed
   */
  FunctionBody parseFunctionBody(bool mayBeEmpty, bool inExpression) {
    bool wasInLoop = _inLoop;
    bool wasInSwitch = _inSwitch;
    _inLoop = false;
    _inSwitch = false;
    try {
      if (matches5(TokenType.SEMICOLON)) {
        if (!mayBeEmpty) {
          reportError4(ParserErrorCode.MISSING_FUNCTION_BODY, []);
        }
        return new EmptyFunctionBody.full(andAdvance);
      } else if (matches5(TokenType.FUNCTION)) {
        Token functionDefinition = andAdvance;
        Expression expression = parseExpression2();
        Token semicolon = null;
        if (!inExpression) {
          semicolon = expect2(TokenType.SEMICOLON);
        }
        return new ExpressionFunctionBody.full(functionDefinition, expression, semicolon);
      } else if (matches5(TokenType.OPEN_CURLY_BRACKET)) {
        return new BlockFunctionBody.full(parseBlock());
      } else if (matches2(_NATIVE)) {
        Token nativeToken = andAdvance;
        StringLiteral stringLiteral = null;
        if (matches5(TokenType.STRING)) {
          stringLiteral = parseStringLiteral();
        }
        return new NativeFunctionBody.full(nativeToken, stringLiteral, expect2(TokenType.SEMICOLON));
      } else {
        reportError4(ParserErrorCode.MISSING_FUNCTION_BODY, []);
        return new EmptyFunctionBody.full(createSyntheticToken2(TokenType.SEMICOLON));
      }
    } finally {
      _inLoop = wasInLoop;
      _inSwitch = wasInSwitch;
    }
  }
  /**
   * Parse a function declaration.
   * <pre>
   * functionDeclaration ::=
   * functionSignature functionBody
   * | returnType? getOrSet identifier formalParameterList functionBody
   * </pre>
   * @param commentAndMetadata the documentation comment and metadata to be associated with the
   * declaration
   * @param externalKeyword the 'external' keyword, or {@code null} if the function is not external
   * @param returnType the return type, or {@code null} if there is no return type
   * @param isStatement {@code true} if the function declaration is being parsed as a statement
   * @return the function declaration that was parsed
   */
  FunctionDeclaration parseFunctionDeclaration(CommentAndMetadata commentAndMetadata, Token externalKeyword, TypeName returnType) {
    Token keyword = null;
    bool isGetter = false;
    if (matches(Keyword.GET) && !matches4(peek(), TokenType.OPEN_PAREN)) {
      keyword = andAdvance;
      isGetter = true;
    } else if (matches(Keyword.SET) && !matches4(peek(), TokenType.OPEN_PAREN)) {
      keyword = andAdvance;
    }
    SimpleIdentifier name = parseSimpleIdentifier();
    FormalParameterList parameters = null;
    if (!isGetter) {
      if (matches5(TokenType.OPEN_PAREN)) {
        parameters = parseFormalParameterList();
        validateFormalParameterList(parameters);
      } else {
        reportError4(ParserErrorCode.MISSING_FUNCTION_PARAMETERS, []);
      }
    } else if (matches5(TokenType.OPEN_PAREN)) {
      reportError4(ParserErrorCode.GETTER_WITH_PARAMETERS, []);
      parseFormalParameterList();
    }
    FunctionBody body;
    if (externalKeyword == null) {
      body = parseFunctionBody(false, false);
    } else {
      body = new EmptyFunctionBody.full(expect2(TokenType.SEMICOLON));
    }
    return new FunctionDeclaration.full(commentAndMetadata.comment, commentAndMetadata.metadata, externalKeyword, returnType, keyword, name, new FunctionExpression.full(parameters, body));
  }
  /**
   * Parse a function declaration statement.
   * <pre>
   * functionDeclarationStatement ::=
   * functionSignature functionBody
   * </pre>
   * @return the function declaration statement that was parsed
   */
  Statement parseFunctionDeclarationStatement() => parseFunctionDeclarationStatement2(parseCommentAndMetadata(), parseOptionalReturnType());
  /**
   * Parse a function declaration statement.
   * <pre>
   * functionDeclarationStatement ::=
   * functionSignature functionBody
   * </pre>
   * @param commentAndMetadata the documentation comment and metadata to be associated with the
   * declaration
   * @param returnType the return type, or {@code null} if there is no return type
   * @return the function declaration statement that was parsed
   */
  Statement parseFunctionDeclarationStatement2(CommentAndMetadata commentAndMetadata, TypeName returnType) => new FunctionDeclarationStatement.full(parseFunctionDeclaration(commentAndMetadata, null, returnType));
  /**
   * Parse a function expression.
   * <pre>
   * functionExpression ::=
   * formalParameterList functionExpressionBody
   * </pre>
   * @return the function expression that was parsed
   */
  FunctionExpression parseFunctionExpression() {
    FormalParameterList parameters = parseFormalParameterList();
    validateFormalParameterList(parameters);
    FunctionBody body = parseFunctionBody(false, true);
    return new FunctionExpression.full(parameters, body);
  }
  /**
   * Parse a function type alias.
   * <pre>
   * functionTypeAlias ::=
   * functionPrefix typeParameterList? formalParameterList ';'
   * functionPrefix ::=
   * returnType? name
   * </pre>
   * @param commentAndMetadata the metadata to be associated with the member
   * @param keyword the token representing the 'typedef' keyword
   * @return the function type alias that was parsed
   */
  FunctionTypeAlias parseFunctionTypeAlias(CommentAndMetadata commentAndMetadata, Token keyword) {
    TypeName returnType = null;
    if (hasReturnTypeInTypeAlias()) {
      returnType = parseReturnType();
    }
    SimpleIdentifier name = parseSimpleIdentifier();
    TypeParameterList typeParameters = null;
    if (matches5(TokenType.LT)) {
      typeParameters = parseTypeParameterList();
    }
    if (matches5(TokenType.SEMICOLON) || matches5(TokenType.EOF)) {
      reportError4(ParserErrorCode.MISSING_TYPEDEF_PARAMETERS, []);
      FormalParameterList parameters = new FormalParameterList.full(createSyntheticToken2(TokenType.OPEN_PAREN), null, null, null, createSyntheticToken2(TokenType.CLOSE_PAREN));
      Token semicolon = expect2(TokenType.SEMICOLON);
      return new FunctionTypeAlias.full(commentAndMetadata.comment, commentAndMetadata.metadata, keyword, returnType, name, typeParameters, parameters, semicolon);
    } else if (!matches5(TokenType.OPEN_PAREN)) {
      reportError4(ParserErrorCode.MISSING_TYPEDEF_PARAMETERS, []);
      return null;
    }
    FormalParameterList parameters = parseFormalParameterList();
    validateFormalParameterList(parameters);
    Token semicolon = expect2(TokenType.SEMICOLON);
    return new FunctionTypeAlias.full(commentAndMetadata.comment, commentAndMetadata.metadata, keyword, returnType, name, typeParameters, parameters, semicolon);
  }
  /**
   * Parse a getter.
   * <pre>
   * getter ::=
   * getterSignature functionBody?
   * getterSignature ::=
   * 'external'? 'static'? returnType? 'get' identifier
   * </pre>
   * @param commentAndMetadata the documentation comment and metadata to be associated with the
   * declaration
   * @param externalKeyword the 'external' token
   * @param staticKeyword the static keyword, or {@code null} if the getter is not static
   * @param the return type that has already been parsed, or {@code null} if there was no return
   * type
   * @return the getter that was parsed
   */
  MethodDeclaration parseGetter(CommentAndMetadata commentAndMetadata, Token externalKeyword, Token staticKeyword, TypeName returnType) {
    Token propertyKeyword = expect(Keyword.GET);
    SimpleIdentifier name = parseSimpleIdentifier();
    if (matches5(TokenType.OPEN_PAREN) && matches4(peek(), TokenType.CLOSE_PAREN)) {
      reportError4(ParserErrorCode.GETTER_WITH_PARAMETERS, []);
      advance();
      advance();
    }
    FunctionBody body = parseFunctionBody(true, false);
    if (externalKeyword != null && body is! EmptyFunctionBody) {
      reportError4(ParserErrorCode.EXTERNAL_GETTER_WITH_BODY, []);
    }
    return new MethodDeclaration.full(commentAndMetadata.comment, commentAndMetadata.metadata, externalKeyword, staticKeyword, returnType, propertyKeyword, null, name, null, body);
  }
  /**
   * Parse a list of identifiers.
   * <pre>
   * identifierList ::=
   * identifier (',' identifier)
   * </pre>
   * @return the list of identifiers that were parsed
   */
  List<SimpleIdentifier> parseIdentifierList() {
    List<SimpleIdentifier> identifiers = new List<SimpleIdentifier>();
    identifiers.add(parseSimpleIdentifier());
    while (matches5(TokenType.COMMA)) {
      advance();
      identifiers.add(parseSimpleIdentifier());
    }
    return identifiers;
  }
  /**
   * Parse an if statement.
   * <pre>
   * ifStatement ::=
   * 'if' '(' expression ')' statement ('else' statement)?
   * </pre>
   * @return the if statement that was parsed
   */
  Statement parseIfStatement() {
    Token ifKeyword = expect(Keyword.IF);
    Token leftParenthesis = expect2(TokenType.OPEN_PAREN);
    Expression condition = parseExpression2();
    Token rightParenthesis = expect2(TokenType.CLOSE_PAREN);
    Statement thenStatement = parseStatement2();
    Token elseKeyword = null;
    Statement elseStatement = null;
    if (matches(Keyword.ELSE)) {
      elseKeyword = andAdvance;
      elseStatement = parseStatement2();
    }
    return new IfStatement.full(ifKeyword, leftParenthesis, condition, rightParenthesis, thenStatement, elseKeyword, elseStatement);
  }
  /**
   * Parse an implements clause.
   * <pre>
   * implementsClause ::=
   * 'implements' type (',' type)
   * </pre>
   * @return the implements clause that was parsed
   */
  ImplementsClause parseImplementsClause() {
    Token keyword = expect(Keyword.IMPLEMENTS);
    List<TypeName> interfaces = new List<TypeName>();
    interfaces.add(parseTypeName());
    while (optional(TokenType.COMMA)) {
      interfaces.add(parseTypeName());
    }
    return new ImplementsClause.full(keyword, interfaces);
  }
  /**
   * Parse an import directive.
   * <pre>
   * importDirective ::=
   * metadata 'import' stringLiteral ('as' identifier)? combinator*';'
   * </pre>
   * @param commentAndMetadata the metadata to be associated with the directive
   * @return the import directive that was parsed
   */
  ImportDirective parseImportDirective(CommentAndMetadata commentAndMetadata) {
    Token importKeyword = expect(Keyword.IMPORT);
    StringLiteral libraryUri = parseStringLiteral();
    Token asToken = null;
    SimpleIdentifier prefix = null;
    if (matches(Keyword.AS)) {
      asToken = andAdvance;
      prefix = parseSimpleIdentifier();
    }
    List<Combinator> combinators = parseCombinators();
    Token semicolon = expect2(TokenType.SEMICOLON);
    return new ImportDirective.full(commentAndMetadata.comment, commentAndMetadata.metadata, importKeyword, libraryUri, asToken, prefix, combinators, semicolon);
  }
  /**
   * Parse a list of initialized identifiers.
   * <pre>
   * ?? ::=
   * 'static'? ('var' | type) initializedIdentifierList ';'
   * | 'final' type? initializedIdentifierList ';'
   * initializedIdentifierList ::=
   * initializedIdentifier (',' initializedIdentifier)
   * initializedIdentifier ::=
   * identifier ('=' expression)?
   * </pre>
   * @param commentAndMetadata the documentation comment and metadata to be associated with the
   * declaration
   * @param staticKeyword the static keyword, or {@code null} if the getter is not static
   * @param keyword the token representing the 'final', 'const' or 'var' keyword, or {@code null} if
   * there is no keyword
   * @param type the type that has already been parsed, or {@code null} if 'var' was provided
   * @return the getter that was parsed
   */
  FieldDeclaration parseInitializedIdentifierList(CommentAndMetadata commentAndMetadata, Token staticKeyword, Token keyword, TypeName type) {
    VariableDeclarationList fieldList = parseVariableDeclarationList2(null, keyword, type);
    return new FieldDeclaration.full(commentAndMetadata.comment, commentAndMetadata.metadata, staticKeyword, fieldList, expect2(TokenType.SEMICOLON));
  }
  /**
   * Parse an instance creation expression.
   * <pre>
   * instanceCreationExpression ::=
   * ('new' | 'const') type ('.' identifier)? argumentList
   * </pre>
   * @param keyword the 'new' or 'const' keyword that introduces the expression
   * @return the instance creation expression that was parsed
   */
  InstanceCreationExpression parseInstanceCreationExpression(Token keyword) {
    ConstructorName constructorName = parseConstructorName();
    ArgumentList argumentList = parseArgumentList();
    return new InstanceCreationExpression.full(keyword, constructorName, argumentList);
  }
  /**
   * Parse a library directive.
   * <pre>
   * libraryDirective ::=
   * metadata 'library' identifier ';'
   * </pre>
   * @param commentAndMetadata the metadata to be associated with the directive
   * @return the library directive that was parsed
   */
  LibraryDirective parseLibraryDirective(CommentAndMetadata commentAndMetadata) {
    Token keyword = expect(Keyword.LIBRARY);
    LibraryIdentifier libraryName = parseLibraryName(ParserErrorCode.MISSING_NAME_IN_LIBRARY_DIRECTIVE, keyword);
    Token semicolon = expect2(TokenType.SEMICOLON);
    return new LibraryDirective.full(commentAndMetadata.comment, commentAndMetadata.metadata, keyword, libraryName, semicolon);
  }
  /**
   * Parse a library identifier.
   * <pre>
   * libraryIdentifier ::=
   * identifier ('.' identifier)
   * </pre>
   * @return the library identifier that was parsed
   */
  LibraryIdentifier parseLibraryIdentifier() {
    List<SimpleIdentifier> components = new List<SimpleIdentifier>();
    components.add(parseSimpleIdentifier());
    while (matches5(TokenType.PERIOD)) {
      advance();
      components.add(parseSimpleIdentifier());
    }
    return new LibraryIdentifier.full(components);
  }
  /**
   * Parse a library name.
   * <pre>
   * libraryName ::=
   * libraryIdentifier
   * </pre>
   * @param missingNameError the error code to be used if the library name is missing
   * @param missingNameToken the token associated with the error produced if the library name is
   * missing
   * @return the library name that was parsed
   */
  LibraryIdentifier parseLibraryName(ParserErrorCode missingNameError, Token missingNameToken) {
    if (matchesIdentifier()) {
      return parseLibraryIdentifier();
    } else if (matches5(TokenType.STRING)) {
      StringLiteral string = parseStringLiteral();
      reportError(ParserErrorCode.NON_IDENTIFIER_LIBRARY_NAME, string, []);
    } else {
      reportError5(missingNameError, missingNameToken, []);
    }
    List<SimpleIdentifier> components = new List<SimpleIdentifier>();
    components.add(createSyntheticIdentifier());
    return new LibraryIdentifier.full(components);
  }
  /**
   * Parse a list literal.
   * <pre>
   * listLiteral ::=
   * 'const'? typeArguments? '\[' (expressionList ','?)? '\]'
   * </pre>
   * @param modifier the 'const' modifier appearing before the literal, or {@code null} if there is
   * no modifier
   * @param typeArguments the type arguments appearing before the literal, or {@code null} if there
   * are no type arguments
   * @return the list literal that was parsed
   */
  ListLiteral parseListLiteral(Token modifier, TypeArgumentList typeArguments) {
    if (matches5(TokenType.INDEX)) {
      BeginToken leftBracket = new BeginToken(TokenType.OPEN_SQUARE_BRACKET, _currentToken.offset);
      Token rightBracket = new Token(TokenType.CLOSE_SQUARE_BRACKET, _currentToken.offset + 1);
      leftBracket.endToken = rightBracket;
      rightBracket.setNext(_currentToken.next);
      leftBracket.setNext(rightBracket);
      _currentToken.previous.setNext(leftBracket);
      _currentToken = _currentToken.next;
      return new ListLiteral.full(modifier, typeArguments, leftBracket, null, rightBracket);
    }
    Token leftBracket = expect2(TokenType.OPEN_SQUARE_BRACKET);
    if (matches5(TokenType.CLOSE_SQUARE_BRACKET)) {
      return new ListLiteral.full(modifier, typeArguments, leftBracket, null, andAdvance);
    }
    List<Expression> elements = new List<Expression>();
    elements.add(parseExpression2());
    while (optional(TokenType.COMMA)) {
      if (matches5(TokenType.CLOSE_SQUARE_BRACKET)) {
        return new ListLiteral.full(modifier, typeArguments, leftBracket, elements, andAdvance);
      }
      elements.add(parseExpression2());
    }
    Token rightBracket = expect2(TokenType.CLOSE_SQUARE_BRACKET);
    return new ListLiteral.full(modifier, typeArguments, leftBracket, elements, rightBracket);
  }
  /**
   * Parse a list or map literal.
   * <pre>
   * listOrMapLiteral ::=
   * listLiteral
   * | mapLiteral
   * </pre>
   * @param modifier the 'const' modifier appearing before the literal, or {@code null} if there is
   * no modifier
   * @return the list or map literal that was parsed
   */
  TypedLiteral parseListOrMapLiteral(Token modifier) {
    TypeArgumentList typeArguments = null;
    if (matches5(TokenType.LT)) {
      typeArguments = parseTypeArgumentList();
    }
    if (matches5(TokenType.OPEN_CURLY_BRACKET)) {
      return parseMapLiteral(modifier, typeArguments);
    } else if (matches5(TokenType.OPEN_SQUARE_BRACKET) || matches5(TokenType.INDEX)) {
      return parseListLiteral(modifier, typeArguments);
    }
    reportError4(ParserErrorCode.EXPECTED_LIST_OR_MAP_LITERAL, []);
    return new ListLiteral.full(modifier, typeArguments, createSyntheticToken2(TokenType.OPEN_SQUARE_BRACKET), null, createSyntheticToken2(TokenType.CLOSE_SQUARE_BRACKET));
  }
  /**
   * Parse a logical and expression.
   * <pre>
   * logicalAndExpression ::=
   * bitwiseOrExpression ('&&' bitwiseOrExpression)
   * </pre>
   * @return the logical and expression that was parsed
   */
  Expression parseLogicalAndExpression() {
    Expression expression = parseBitwiseOrExpression();
    while (matches5(TokenType.AMPERSAND_AMPERSAND)) {
      Token operator = andAdvance;
      expression = new BinaryExpression.full(expression, operator, parseBitwiseOrExpression());
    }
    return expression;
  }
  /**
   * Parse a logical or expression.
   * <pre>
   * logicalOrExpression ::=
   * logicalAndExpression ('||' logicalAndExpression)
   * </pre>
   * @return the logical or expression that was parsed
   */
  Expression parseLogicalOrExpression() {
    Expression expression = parseLogicalAndExpression();
    while (matches5(TokenType.BAR_BAR)) {
      Token operator = andAdvance;
      expression = new BinaryExpression.full(expression, operator, parseLogicalAndExpression());
    }
    return expression;
  }
  /**
   * Parse a map literal.
   * <pre>
   * mapLiteral ::=
   * 'const'? typeArguments? '{' (mapLiteralEntry (',' mapLiteralEntry)* ','?)? '}'
   * </pre>
   * @param modifier the 'const' modifier appearing before the literal, or {@code null} if there is
   * no modifier
   * @param typeArguments the type arguments that were declared, or {@code null} if there are no
   * type arguments
   * @return the map literal that was parsed