Add breaking changes and release 1.0.0.

test/string_scanner_test.dart

 // Copyright (c) 2014, 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.
 
 import 'package:charcode/charcode.dart';
 import 'package:string_scanner/string_scanner.dart';
 import 'package:test/test.dart';
 
 void main() {
   group('with an empty string', () {
@@ skipping 243 matching lines @@
 
       expect(scanner.scan(new RegExp(' b(..)')), isTrue);
       expect(scanner.lastMatch[1], equals('ar'));
       expect(scanner.position, equals(7));
       expect(scanner.rest, equals(''));
       expect(scanner.isDone, isTrue);
       expect(scanner.expectDone, isNot(throwsFormatException));
     });
   });
 
+  group('after a scan', () {
+    var scanner;
+    setUp(() {
+      scanner = new StringScanner('foo bar');
+      expect(scanner.scan('foo'), isTrue);
+    });
+
+    test('readChar returns the first character and unsets the last match', () {
+      expect(scanner.readChar(), equals($space));
+      expect(scanner.lastMatch, isNull);
+      expect(scanner.position, equals(4));
+    });
+
+    test('a matching scanChar returns true and unsets the last match', () {
+      expect(scanner.scanChar($space), isTrue);
+      expect(scanner.lastMatch, isNull);
+      expect(scanner.position, equals(4));
+    });
+
+    test('a matching expectChar returns true and unsets the last match', () {
+      scanner.expectChar($space);
+      expect(scanner.lastMatch, isNull);
+      expect(scanner.position, equals(4));
+    });
+  });
+
   group('at the end of a string', () {
     var scanner;
     setUp(() {
       scanner = new StringScanner('foo bar');
       expect(scanner.scan('foo bar'), isTrue);
     });
 
     test('is done', () {
       expect(scanner.isDone, isTrue);
       expect(scanner.expectDone, isNot(throwsFormatException));
@@ skipping 65 matching lines @@
       scanner.position = 1;
       expect(scanner.position, equals(1));
       expect(scanner.rest, equals('oo bar'));
 
       expect(scanner.scan(new RegExp('oo.')), isTrue);
       expect(scanner.lastMatch[0], equals('oo '));
       expect(scanner.position, equals(4));
       expect(scanner.rest, equals('bar'));
     });
 
+    test('setting and resetting position clears lastMatch', () {
+      var oldPosition = scanner.position;
+      scanner.position = 1;
+      scanner.position = oldPosition;
+      expect(scanner.lastMatch, isNull);
+    });
+
     test('setting position beyond the string throws an ArgumentError', () {
       expect(() {
         scanner.position = 8;
       }, throwsArgumentError);
     });
 
     test('setting position to -1 throws an ArgumentError', () {
       expect(() {
         scanner.position = -1;
       }, throwsArgumentError);
@@ skipping 16 matching lines @@
       expect(() => new StringScanner('foo bar', position: -1),
           throwsArgumentError);
     });
 
     test('throws an ArgumentError if the position is beyond the string', () {
       expect(
           () => new StringScanner('foo bar', position: 8), throwsArgumentError);
     });
   });
 }