Initial task support

pkg/analyzer/lib/task/general.dart

+// Copyright (c) 2015, 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.task.general;
+
+import 'package:analyzer/src/generated/error.dart';
+import 'package:analyzer/src/generated/source.dart';
+import 'package:analyzer/task/model.dart';
+
+/**
+ * The analysis errors associated with a target.
+ *
+ * The value combines errors represented by multiple other results.
+ */
+// TODO(brianwilkerson) If we want to associate errors with targets smaller than
+// a file, we will need other contribution points to collect them. In which case
+// we might want to rename this and/or document that it applies to files. For
+// that matter, we might also want to have one that applies to Dart files and a
+// different one that applies to HTML files, because the list of errors being
+// combined is likely to be different.
+final ContributionPoint<List<AnalysisError>> ANALYSIS_ERRORS =
+    new ContributionPoint<List<AnalysisError>>('ANALYSIS_ERRORS');
+
+/**
+ * The contents of a single file.
+ */
+final ResultDescriptor<String> CONTENT =
+    new ResultDescriptor<String>('CONTENT');
+
+/**
+ * The line information for a single file.
+ */
+final ResultDescriptor<LineInfo> LINE_INFO =
+    new ResultDescriptor<LineInfo>('LINE_INFO');
+
+/**
+ * The modification time of a file.
+ */
+final ResultDescriptor<int> MODIFICATION_TIME =
+    new ResultDescriptor<int>('MODIFICATION_TIME');
+
+/**
+ * The kind of a [Source].
+ */
+final ResultDescriptor<SourceKind> SOURCE_KIND =
+    new ResultDescriptor<SourceKind>('SOURCE_KIND');