| // Copyright (c) 2011, 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.scanner.string_scanner; |
| |
| import 'token.dart' show Token, SyntheticStringToken, TokenType; |
| |
| import 'token.dart' as analyzer show StringToken; |
| |
| import 'abstract_scanner.dart' |
| show AbstractScanner, LanguageVersionChanged, ScannerConfiguration; |
| |
| import 'token_impl.dart' |
| show CommentToken, DartDocToken, LanguageVersionToken, StringToken; |
| |
| import 'error_token.dart' show ErrorToken; |
| |
| /** |
| * Scanner that reads from a String and creates tokens that points to |
| * substrings. |
| */ |
| class StringScanner extends AbstractScanner { |
| /** The file content. */ |
| final String string; |
| |
| /** The current offset in [string]. */ |
| int scanOffset = -1; |
| |
| StringScanner(String string, |
| {ScannerConfiguration? configuration, |
| bool includeComments: false, |
| LanguageVersionChanged? languageVersionChanged}) |
| : string = ensureZeroTermination(string), |
| super(configuration, includeComments, languageVersionChanged); |
| |
| StringScanner.recoveryOptionScanner(StringScanner copyFrom) |
| : string = copyFrom.string, |
| scanOffset = copyFrom.scanOffset, |
| super.recoveryOptionScanner(copyFrom); |
| |
| StringScanner createRecoveryOptionScanner() { |
| return new StringScanner.recoveryOptionScanner(this); |
| } |
| |
| static String ensureZeroTermination(String string) { |
| return (string.isEmpty || string.codeUnitAt(string.length - 1) != 0) |
| // TODO(lry): abort instead of copying the array, or warn? |
| ? string + '\x00' |
| : string; |
| } |
| |
| static bool isLegalIdentifier(String identifier) { |
| StringScanner scanner = new StringScanner(identifier); |
| Token startToken = scanner.tokenize(); |
| return startToken is! ErrorToken && startToken.next!.isEof; |
| } |
| |
| int advance() => string.codeUnitAt(++scanOffset); |
| int peek() => string.codeUnitAt(scanOffset + 1); |
| |
| int get stringOffset => scanOffset; |
| |
| int currentAsUnicode(int next) => next; |
| |
| void handleUnicode(int startScanOffset) {} |
| |
| @override |
| analyzer.StringToken createSubstringToken( |
| TokenType type, int start, bool asciiOnly, |
| [int extraOffset = 0]) { |
| return new StringToken.fromSubstring( |
| type, string, start, scanOffset + extraOffset, tokenStart, |
| canonicalize: true, precedingComments: comments); |
| } |
| |
| @override |
| analyzer.StringToken createSyntheticSubstringToken( |
| TokenType type, int start, bool asciiOnly, String syntheticChars) { |
| String source = string.substring(start, scanOffset); |
| return new SyntheticStringToken( |
| type, source + syntheticChars, tokenStart, source.length); |
| } |
| |
| @override |
| CommentToken createCommentToken(TokenType type, int start, bool asciiOnly, |
| [int extraOffset = 0]) { |
| return new CommentToken.fromSubstring( |
| type, string, start, scanOffset + extraOffset, tokenStart, |
| canonicalize: true); |
| } |
| |
| @override |
| DartDocToken createDartDocToken(TokenType type, int start, bool asciiOnly, |
| [int extraOffset = 0]) { |
| return new DartDocToken.fromSubstring( |
| type, string, start, scanOffset + extraOffset, tokenStart, |
| canonicalize: true); |
| } |
| |
| @override |
| LanguageVersionToken createLanguageVersionToken( |
| int start, int major, int minor) { |
| return new LanguageVersionToken.fromSubstring( |
| string, start, scanOffset, tokenStart, major, minor, |
| canonicalize: true); |
| } |
| |
| bool atEndOfFile() => scanOffset >= string.length - 1; |
| } |