Move scanner into pkg/front_end/lib/src/scanner.

pkg/front_end/lib/src/scanner/scanner.dart

-// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2016, 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 analyzer.src.dart.scanner.scanner;
+library front_end.src.scanner.scanner;
 
-import 'package:analyzer/dart/ast/token.dart';
-import 'package:analyzer/error/error.dart';
-import 'package:analyzer/error/listener.dart';
-import 'package:analyzer/src/dart/ast/token.dart';
-import 'package:analyzer/src/dart/error/syntactic_errors.dart';
-import 'package:analyzer/src/dart/scanner/reader.dart';
-import 'package:analyzer/src/generated/java_engine.dart';
-import 'package:analyzer/src/generated/source.dart';
 import 'package:charcode/ascii.dart';
-
-export 'package:analyzer/src/dart/error/syntactic_errors.dart';
+import 'package:front_end/src/scanner/errors.dart';
+import 'package:front_end/src/scanner/reader.dart';
+import 'package:front_end/src/scanner/string_utilities.dart';
+import 'package:front_end/src/scanner/token.dart';
 
 /**
  * A state in a state machine used to scan keywords.
  */
 class KeywordState {
   /**
    * An empty transition table used by leaf states.
    */
   static List<KeywordState> _EMPTY_TABLE = new List<KeywordState>(26);
 
@@ skipping 97 matching lines @@
 /**
  * The class `Scanner` implements a scanner for Dart code.
  *
  * The lexical structure of Dart is ambiguous without knowledge of the context
  * in which a token is being scanned. For example, without context we cannot
  * determine whether source of the form "<<" should be scanned as a single
  * left-shift operator or as two left angle brackets. This scanner does not have
  * any context, so it always resolves such conflicts by scanning the longest
  * possible token.
  */
-class Scanner {
-  /**
-   * The source being scanned.
-   */
-  final Source source;
-
+abstract class Scanner {
   /**
    * The reader used to access the characters in the source.
    */
   final CharacterReader _reader;
 
   /**
-   * The error listener that will be informed of any errors that are found
-   * during the scan.
-   */
-  final AnalysisErrorListener _errorListener;
-
-  /**
    * The flag specifying whether documentation comments should be parsed.
    */
   bool _preserveComments = true;
 
   /**
    * The token pointing to the head of the linked list of tokens.
    */
   Token _tokens;
 
   /**
@@ skipping 49 matching lines @@
   bool scanGenericMethodComments = false;
 
   /**
    * A flag indicating whether the lazy compound assignment operators '&&=' and
    * '||=' are enabled.
    */
   bool scanLazyAssignmentOperators = false;
 
   /**
    * Initialize a newly created scanner to scan characters from the given
-   * [source]. The given character [_reader] will be used to read the characters
-   * in the source. The given [_errorListener] will be informed of any errors
-   * that are found.
+   * character [_reader].
    */
-  Scanner(this.source, this._reader, this._errorListener) {
+  Scanner(this._reader) {
     _tokens = new Token(TokenType.EOF, -1);
     _tokens.setNext(_tokens);
     _tail = _tokens;
     _tokenStart = -1;
     _lineStarts.add(0);
   }
 
   /**
    * Return the first token in the token stream that was scanned.
    */
@@ skipping 215 matching lines @@
   }
 
   /**
    * Record the fact that we are at the beginning of a new line in the source.
    */
   void recordStartOfLine() {
     _lineStarts.add(_reader.offset);
   }
 
   /**
+   * Report an error at the given offset. The [errorCode] is the error code
+   * indicating the nature of the error. The [arguments] are any arguments
+   * needed to complete the error message
+   */
+  void reportError(
+      ScannerErrorCode errorCode, int offset, List<Object> arguments);
+
+  /**
    * Record that the source begins on the given [line] and [column] at the
    * current offset as given by the reader. Both the line and the column are
    * one-based indexes. The line starts for lines before the given line will not
    * be correct.
    *
    * This method must be invoked at most one time and must be invoked before
    * scanning begins. The values provided must be sensible. The results are
    * undefined if these conditions are violated.
    */
   void setSourceStart(int line, int column) {
@@ skipping 198 matching lines @@
     }
     return null;
   }
 
   /**
    * Report an error at the current offset. The [errorCode] is the error code
    * indicating the nature of the error. The [arguments] are any arguments
    * needed to complete the error message
    */
   void _reportError(ScannerErrorCode errorCode, [List<Object> arguments]) {
-    _errorListener.onError(
-        new AnalysisError(source, _reader.offset, 1, errorCode, arguments));
+    reportError(errorCode, _reader.offset, arguments);
   }
 
   int _select(int choice, TokenType yesType, TokenType noType) {
     int next = _reader.advance();
     if (next == choice) {
       _appendTokenOfType(yesType);
       return _reader.advance();
     } else {
       _appendTokenOfType(noType);
       return next;
@@ skipping 654 matching lines @@
   }
 
   /**
    * Checks if [value] is a single-line or multi-line comment.
    */
   static bool _isDocumentationComment(String value) {
     return StringUtilities.startsWith3(value, 0, $slash, $slash, $slash) ||
         StringUtilities.startsWith3(value, 0, $slash, $asterisk, $asterisk);
   }
 }