Precompute `IgnoreInfo` in Scanner.

pkg/analyzer/lib/src/generated/source.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.
 
 library analyzer.src.generated.source;
 
 import 'dart:collection';
 import "dart:math" as math;
 
 import 'package:analyzer/file_system/file_system.dart';
@@ skipping 159 matching lines @@
   /**
    * Return `true` if the given URI is a `dart:` URI.
    *
    * @param uri the URI being tested
    * @return `true` if the given URI is a `dart:` URI
    */
   static bool isDartUri(Uri uri) => DART_SCHEME == uri.scheme;
 }
 
 /**
+ * Information about analysis `//ignore:` comments within a source file.
+ */
+class IgnoreInfo {

[scheglov, 2016/05/27 18:05:47]

This could live in src/dart.dart

[pquitslund, 2016/05/27 21:50:53]

Done.

+  final Map<int, List<String>> _ignoreMap = new HashMap<int, List<String>>();
+
+  /**
+   * Map of line numbers to associated ignored error codes.
+   */
+  Map<int, Iterable<String>> get ignores => _ignoreMap;
+
+  /**
+   * Ignore this [errorCode] at [line].
+   */
+  void add(int line, String errorCode) {
+    _ignoreMap.putIfAbsent(line, () => new List<String>()).add(errorCode);
+  }
+
+  /**
+   * Whether this info object defines any ignores.
+   */
+  bool get hasIgnores => ignores.length > 0;

[scheglov, 2016/05/27 18:05:47]

=> ignores.isNotEmpty;

[pquitslund, 2016/05/27 21:50:53]

Done.

+
+  /**
+   * Test whether this [errorCode] is ignored at the given [line].
+   */
+  bool ignoredAt(String errorCode, int line) =>
+      _ignoreMap[line]?.contains(errorCode) == true;
+}
+
+/**
  * Information about line and column information within a source file.
  */
 class LineInfo {
   /**
    * A list containing the offsets of the first character of each line in the
    * source code.
    */
   final List<int> _lineStarts;
 
   /**
@@ skipping 740 matching lines @@
   Source resolveAbsolute(Uri uri, [Uri actualUri]);
 
   /**
    * Return an absolute URI that represents the given [source], or `null` if a
    * valid URI cannot be computed.
    *
    * The computation should be based solely on [source.fullName].
    */
   Uri restoreAbsolute(Source source) => null;
 }