pkg/compiler/lib/src/parser/listener.dart

// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

library dart2js.parser.listener;

import '../common.dart';
import '../diagnostics/messages.dart' show
    MessageTemplate;
import '../tokens/precedence_constants.dart' as Precedence show
    EOF_INFO,
    IDENTIFIER_INFO;
import '../tokens/token.dart' show
    BadInputToken,
    BeginGroupToken,
    ErrorToken,
    StringToken,
    Token,
    UnmatchedToken,
    UnterminatedToken;
import '../tree/tree.dart';

const bool VERBOSE = false;

/**
 * A parser event listener that does nothing except throw exceptions
 * on parser errors.
 */
class Listener {
  set suppressParseErrors(bool value) {
  }

  void beginArguments(Token token) {
  }

  void endArguments(int count, Token beginToken, Token endToken) {
  }

  /// Handle async modifiers `async`, `async*`, `sync`.
  void handleAsyncModifier(Token asyncToken, Token startToken) {
  }

  void beginAwaitExpression(Token token) {
  }

  void endAwaitExpression(Token beginToken, Token endToken) {
  }

  void beginBlock(Token token) {
  }

  void endBlock(int count, Token beginToken, Token endToken) {
  }

  void beginCascade(Token token) {
  }

  void endCascade() {
  }

  void beginClassBody(Token token) {
  }

  void endClassBody(int memberCount, Token beginToken, Token endToken) {
  }

  void beginClassDeclaration(Token token) {
  }

  void endClassDeclaration(int interfacesCount, Token beginToken,
                           Token extendsKeyword, Token implementsKeyword,
                           Token endToken) {
  }

  void beginCombinators(Token token) {
  }

  void endCombinators(int count) {
  }

  void beginCompilationUnit(Token token) {
  }

  void endCompilationUnit(int count, Token token) {
  }

  void beginConstructorReference(Token start) {
  }

  void endConstructorReference(Token start, Token periodBeforeName,
                               Token endToken) {
  }

  void beginDoWhileStatement(Token token) {
  }

  void endDoWhileStatement(Token doKeyword, Token whileKeyword,
                           Token endToken) {
  }

  void beginEnum(Token enumKeyword) {
  }

  void endEnum(Token enumKeyword, Token endBrace, int count) {
  }

  void beginExport(Token token) {
  }

  void endExport(Token exportKeyword, Token semicolon) {
  }

  void beginExpressionStatement(Token token) {
  }

  void endExpressionStatement(Token token) {
  }

  void beginFactoryMethod(Token token) {
  }

  void endFactoryMethod(Token beginToken, Token endToken) {
  }

  void beginFormalParameter(Token token) {
  }

  void endFormalParameter(Token thisKeyword) {
  }

  void handleNoFormalParameters(Token token) {
  }

  void beginFormalParameters(Token token) {
  }

  void endFormalParameters(int count, Token beginToken, Token endToken) {
  }

  void endFields(int count, Token beginToken, Token endToken) {
  }

  void beginForStatement(Token token) {
  }

  void endForStatement(int updateExpressionCount,
                       Token beginToken, Token endToken) {
  }

  void endForIn(Token awaitToken, Token forToken,
                Token inKeyword, Token endToken) {
  }

  void beginFunction(Token token) {
  }

  void endFunction(Token getOrSet, Token endToken) {
  }

  void beginFunctionDeclaration(Token token) {
  }

  void endFunctionDeclaration(Token token) {
  }

  void beginFunctionBody(Token token) {
  }

  void endFunctionBody(int count, Token beginToken, Token endToken) {
  }

  void handleNoFunctionBody(Token token) {
  }

  void skippedFunctionBody(Token token) {
  }

  void beginFunctionName(Token token) {
  }

  void endFunctionName(Token token) {
  }

  void beginFunctionTypeAlias(Token token) {
  }

  void endFunctionTypeAlias(Token typedefKeyword, Token endToken) {
  }

  void beginMixinApplication(Token token) {
  }

  void endMixinApplication() {
  }

  void beginNamedMixinApplication(Token token) {
  }

  void endNamedMixinApplication(Token classKeyword,
                                Token implementsKeyword,
                                Token endToken) {
  }

  void beginHide(Token hideKeyword) {
  }

  void endHide(Token hideKeyword) {
  }

  void beginIdentifierList(Token token) {
  }

  void endIdentifierList(int count) {
  }

  void beginTypeList(Token token) {
  }

  void endTypeList(int count) {
  }

  void beginIfStatement(Token token) {
  }

  void endIfStatement(Token ifToken, Token elseToken) {
  }

  void beginImport(Token importKeyword) {
  }

  void endImport(Token importKeyword, Token DeferredKeyword,
                 Token asKeyword, Token semicolon) {
  }

  void beginConditionalUris(Token token) {
  }

  void endConditionalUris(int count) {
  }

  void beginConditionalUri(Token ifKeyword) {
  }

  void endConditionalUri(Token ifKeyword, Token equalitySign) {
  }

  void beginDottedName(Token token) {
  }

  void endDottedName(int count, Token firstIdentifier) {
  }

  void beginInitializedIdentifier(Token token) {
  }

  void endInitializedIdentifier() {
  }

  void beginInitializer(Token token) {
  }

  void endInitializer(Token assignmentOperator) {
  }

  void beginInitializers(Token token) {
  }

  void endInitializers(int count, Token beginToken, Token endToken) {
  }

  void handleNoInitializers() {
  }

  void handleLabel(Token token) {
  }

  void beginLabeledStatement(Token token, int labelCount) {
  }

  void endLabeledStatement(int labelCount) {
  }

  void beginLibraryName(Token token) {
  }

  void endLibraryName(Token libraryKeyword, Token semicolon) {
  }

  void beginLiteralMapEntry(Token token) {
  }

  void endLiteralMapEntry(Token colon, Token endToken) {
  }

  void beginLiteralString(Token token) {
  }

  void endLiteralString(int interpolationCount) {
  }

  void handleStringJuxtaposition(int literalCount) {
  }

  void beginMember(Token token) {
  }

  void endMethod(Token getOrSet, Token beginToken, Token endToken) {
  }

  void beginMetadataStar(Token token) {
  }

  void endMetadataStar(int count, bool forParameter) {
  }

  void beginMetadata(Token token) {
  }

  void endMetadata(Token beginToken, Token periodBeforeName, Token endToken) {
  }

  void beginOptionalFormalParameters(Token token) {
  }

  void endOptionalFormalParameters(int count,
                                   Token beginToken, Token endToken) {
  }

  void beginPart(Token token) {
  }

  void endPart(Token partKeyword, Token semicolon) {
  }

  void beginPartOf(Token token) {
  }

  void endPartOf(Token partKeyword, Token semicolon) {
  }

  void beginRedirectingFactoryBody(Token token) {
  }

  void endRedirectingFactoryBody(Token beginToken, Token endToken) {
  }

  void beginReturnStatement(Token token) {
  }

  void endReturnStatement(bool hasExpression,
                          Token beginToken, Token endToken) {
  }

  void beginSend(Token token) {
  }

  void endSend(Token token) {
  }

  void beginShow(Token showKeyword) {
  }

  void endShow(Token showKeyword) {
  }

  void beginSwitchStatement(Token token) {
  }

  void endSwitchStatement(Token switchKeyword, Token endToken) {
  }

  void beginSwitchBlock(Token token) {
  }

  void endSwitchBlock(int caseCount, Token beginToken, Token endToken) {
  }

  void beginLiteralSymbol(Token token) {
  }

  void endLiteralSymbol(Token hashToken, int identifierCount) {
  }

  void beginThrowExpression(Token token) {
  }

  void endThrowExpression(Token throwToken, Token endToken) {
  }

  void beginRethrowStatement(Token token) {
  }

  void endRethrowStatement(Token throwToken, Token endToken) {
  }

  void endTopLevelDeclaration(Token token) {
  }

  void beginTopLevelMember(Token token) {
  }

  void endTopLevelFields(int count, Token beginToken, Token endToken) {
  }

  void endTopLevelMethod(Token beginToken, Token getOrSet, Token endToken) {
  }

  void beginTryStatement(Token token) {
  }

  void handleCaseMatch(Token caseKeyword, Token colon) {
  }

  void handleCatchBlock(Token onKeyword, Token catchKeyword) {
  }

  void handleFinallyBlock(Token finallyKeyword) {
  }

  void endTryStatement(int catchCount, Token tryKeyword, Token finallyKeyword) {
  }

  void endType(Token beginToken, Token endToken) {
  }

  void beginTypeArguments(Token token) {
  }

  void endTypeArguments(int count, Token beginToken, Token endToken) {
  }

  void handleNoTypeArguments(Token token) {
  }

  void beginTypeVariable(Token token) {
  }

  void endTypeVariable(Token token) {
  }

  void beginTypeVariables(Token token) {
  }

  void endTypeVariables(int count, Token beginToken, Token endToken) {
  }

  void beginUnnamedFunction(Token token) {
  }

  void endUnnamedFunction(Token token) {
  }

  void beginVariablesDeclaration(Token token) {
  }

  void endVariablesDeclaration(int count, Token endToken) {
  }

  void beginWhileStatement(Token token) {
  }

  void endWhileStatement(Token whileKeyword, Token endToken) {
  }

  void handleAsOperator(Token operathor, Token endToken) {
    // TODO(ahe): Rename [operathor] to "operator" when VM bug is fixed.
  }

  void handleAssignmentExpression(Token token) {
  }

  void handleBinaryExpression(Token token) {
  }

  void handleConditionalExpression(Token question, Token colon) {
  }

  void handleConstExpression(Token token) {
  }

  void handleFunctionTypedFormalParameter(Token token) {
  }

  void handleIdentifier(Token token) {
  }

  void handleIndexedExpression(Token openCurlyBracket,
                               Token closeCurlyBracket) {
  }

  void handleIsOperator(Token operathor, Token not, Token endToken) {
    // TODO(ahe): Rename [operathor] to "operator" when VM bug is fixed.
  }

  void handleLiteralBool(Token token) {
  }

  void handleBreakStatement(bool hasTarget,
                            Token breakKeyword, Token endToken) {
  }

  void handleContinueStatement(bool hasTarget,
                               Token continueKeyword, Token endToken) {
  }

  void handleEmptyStatement(Token token) {
  }

  void handleAssertStatement(Token assertKeyword,
                             Token commaToken, Token semicolonToken) {
  }

  /** Called with either the token containing a double literal, or
    * an immediately preceding "unary plus" token.
    */
  void handleLiteralDouble(Token token) {
  }

  /** Called with either the token containing an integer literal,
    * or an immediately preceding "unary plus" token.
    */
  void handleLiteralInt(Token token) {
  }

  void handleLiteralList(int count, Token beginToken, Token constKeyword,
                         Token endToken) {
  }

  void handleLiteralMap(int count, Token beginToken, Token constKeyword,
                        Token endToken) {
  }

  void handleLiteralNull(Token token) {
  }

  void handleModifier(Token token) {
  }

  void handleModifiers(int count) {
  }

  void handleNamedArgument(Token colon) {
  }

  void handleNewExpression(Token token) {
  }

  void handleNoArguments(Token token) {
  }

  void handleNoExpression(Token token) {
  }

  void handleNoType(Token token) {
  }

  void handleNoTypeVariables(Token token) {
  }

  void handleOperator(Token token) {
  }

  void handleOperatorName(Token operatorKeyword, Token token) {
  }

  void handleParenthesizedExpression(BeginGroupToken token) {
  }

  void handleQualified(Token period) {
  }

  void handleStringPart(Token token) {
  }

  void handleSuperExpression(Token token) {
  }

  void handleSwitchCase(int labelCount, int expressionCount,
                        Token defaultKeyword, int statementCount,
                        Token firstToken, Token endToken) {
  }

  void handleThisExpression(Token token) {
  }

  void handleUnaryPostfixAssignmentExpression(Token token) {
  }

  void handleUnaryPrefixExpression(Token token) {
  }

  void handleUnaryPrefixAssignmentExpression(Token token) {
  }

  void handleValuedFormalParameter(Token equals, Token token) {
  }

  void handleVoidKeyword(Token token) {
  }

  void beginYieldStatement(Token token) {
  }

  void endYieldStatement(Token yieldToken, Token starToken, Token endToken) {
  }

  Token expected(String string, Token token) {
    if (token is ErrorToken) {
      reportErrorToken(token);
    } else {
      error("expected '$string', but got '${token.value}'", token);
    }
    return skipToEof(token);
  }

  Token synthesizeIdentifier(Token token) {
    Token synthesizedToken =
        new StringToken.fromString(
            Precedence.IDENTIFIER_INFO, '?', token.charOffset);
    synthesizedToken.next = token.next;
    return synthesizedToken;
  }

  Token expectedIdentifier(Token token) {
    if (token is ErrorToken) {
      reportErrorToken(token);
    } else {
      error("expected identifier, but got '${token.value}'", token);
    }
    return skipToEof(token);
  }

  Token expectedType(Token token) {
    if (token is ErrorToken) {
      reportErrorToken(token);
    } else {
      error("expected a type, but got '${token.value}'", token);
    }
    return skipToEof(token);
  }

  Token expectedExpression(Token token) {
    if (token is ErrorToken) {
      reportErrorToken(token);
    } else {
      error("expected an expression, but got '${token.value}'", token);
    }
    return skipToEof(token);
  }

  Token unexpected(Token token) {
    if (token is ErrorToken) {
      reportErrorToken(token);
    } else {
      error("unexpected token '${token.value}'", token);
    }
    return skipToEof(token);
  }

  Token expectedBlockToSkip(Token token) {
    if (token is ErrorToken) {
      reportErrorToken(token);
    } else {
      error("expected a block, but got '${token.value}'", token);
    }
    return skipToEof(token);
  }

  Token expectedFunctionBody(Token token) {
    if (token is ErrorToken) {
      reportErrorToken(token);
    } else {
      error("expected a function body, but got '${token.value}'", token);
    }
    return skipToEof(token);
  }

  Token expectedClassBody(Token token) {
    if (token is ErrorToken) {
      reportErrorToken(token);
    } else {
      error("expected a class body, but got '${token.value}'", token);
    }
    return skipToEof(token);
  }

  Token expectedClassBodyToSkip(Token token) {
    if (token is ErrorToken) {
      reportErrorToken(token);
    } else {
      error("expected a class body, but got '${token.value}'", token);
    }
    return skipToEof(token);
  }

  Token expectedDeclaration(Token token) {
    if (token is ErrorToken) {
      reportErrorToken(token);
    } else {
      error("expected a declaration, but got '${token.value}'", token);
    }
    return skipToEof(token);
  }

  Token unmatched(Token token) {
    if (token is ErrorToken) {
      reportErrorToken(token);
    } else {
      error("unmatched '${token.value}'", token);
    }
    return skipToEof(token);
  }

  skipToEof(Token token) {
    while (!identical(token.info, Precedence.EOF_INFO)) {
      token = token.next;
    }
    return token;
  }

  void recoverableError(Token token, String message) {
    error(message, token);
  }

  void error(String message, Token token) {
    throw new ParserError("$message @ ${token.charOffset}");
  }

  void reportError(Spannable spannable,
                   MessageKind messageKind,
                   [Map arguments = const {}]) {
    MessageTemplate template = MessageTemplate.TEMPLATES[messageKind];
    String message = template.message(arguments, true).toString();
    Token token;
    if (spannable is Token) {
      token = spannable;
    } else if (spannable is Node) {
      token = spannable.getBeginToken();
    } else {
      throw new ParserError(message);
    }
    recoverableError(token, message);
  }

  void reportErrorToken(ErrorToken token) {
    if (token is BadInputToken) {
      String hex = token.character.toRadixString(16);
      if (hex.length < 4) {
        String padding = "0000".substring(hex.length);
        hex = "$padding$hex";
      }
      reportError(
          token, MessageKind.BAD_INPUT_CHARACTER, {'characterHex': hex});
    } else if (token is UnterminatedToken) {
      MessageKind kind;
      var arguments = const {};
      switch (token.start) {
        case '1e':
          kind = MessageKind.EXPONENT_MISSING;
          break;
        case '"':
        case "'":
        case '"""':
        case "'''":
        case 'r"':
        case "r'":
        case 'r"""':
        case "r'''":
          kind = MessageKind.UNTERMINATED_STRING;
          arguments = {'quote': token.start};
          break;
        case '0x':
          kind = MessageKind.HEX_DIGIT_EXPECTED;
          break;
        case r'$':
          kind = MessageKind.MALFORMED_STRING_LITERAL;
          break;
        case '/*':
          kind = MessageKind.UNTERMINATED_COMMENT;
          break;
        default:
          kind = MessageKind.UNTERMINATED_TOKEN;
          break;
      }
      reportError(token, kind, arguments);
    } else if (token is UnmatchedToken) {
      String begin = token.begin.value;
      String end = closeBraceFor(begin);
      reportError(
          token, MessageKind.UNMATCHED_TOKEN, {'begin': begin, 'end': end});
    } else {
      throw new SpannableAssertionFailure(token, token.assertionMessage);
    }
  }
}

String closeBraceFor(String openBrace) {
  return const {
    '(': ')',
    '[': ']',
    '{': '}',
    '<': '>',
    r'${': '}',
  }[openBrace];
}

class ParserError {
  final String reason;
  ParserError(this.reason);
  toString() => reason;
}