Add some user-friendly utility functions to pkg/analyzer_experimental.

pkg/analyzer_experimental/lib/analyzer.dart

Index: pkg/analyzer_experimental/lib/analyzer.dart
diff --git a/pkg/analyzer_experimental/lib/analyzer.dart b/pkg/analyzer_experimental/lib/analyzer.dart
index 47f0129246e018a4386d3610ec63803b26f8344f..bad687394d98dbda725edd80a099fb92eedac755 100644
--- a/pkg/analyzer_experimental/lib/analyzer.dart
+++ b/pkg/analyzer_experimental/lib/analyzer.dart
@@ -1,134 +1,64 @@
 // Copyright (c) 2013, 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.
-part of analyzer;
 
-/// Analyzes single library [File].
-class _AnalyzerImpl {
-  final CommandLineOptions options;
-  DartSdk sdk;
+library analyzer;
 
-  ContentCache contentCache = new ContentCache();
-  SourceFactory sourceFactory;
-  AnalysisContext context;
+import 'dart:io';
 
-  /// All [Source]s references by the analyzed library.
-  final Set<Source> sources = new Set<Source>();
+import 'src/error.dart';
+import 'src/generated/ast.dart';
+import 'src/generated/error.dart';
+import 'src/generated/java_io.dart';
+import 'src/generated/parser.dart';
+import 'src/generated/scanner.dart';
+import 'src/generated/source_io.dart';
+import 'src/utils.dart';
 
-  /// All [AnalysisErrorInfo]s in the analyzed library.
-  final List<AnalysisErrorInfo> errorInfos = new List<AnalysisErrorInfo>();
+export 'src/error.dart';
+export 'src/generated/ast.dart';
+export 'src/generated/error.dart';
 
-  _AnalyzerImpl(CommandLineOptions this.options) {
-    sdk = new DirectoryBasedDartSdk(new JavaFile(options.dartSdkPath));
-  }
+/// Parses a Dart file into an AST.
+CompilationUnit parseDartFile(String path) {
+  var contents = new File(path).readAsStringSync();
+  var errorCollector = new _ErrorCollector();
+  var sourceFactory = new SourceFactory.con2([new FileUriResolver()]);
+  var source = sourceFactory.forUri(pathToFileUri(path).toString());
+  var scanner = new StringScanner(source, contents, errorCollector);
+  var token = scanner.tokenize();
+  var parser = new Parser(source, errorCollector);
+  var unit = parser.parseCompilationUnit(token);
+  unit.lineInfo = new LineInfo(scanner.lineStarts);
 
-  /**
-   * Treats the [sourcePath] as the top level library and analyzes it.
-   */
-  void analyze(String sourcePath) {
-    sources.clear();
-    errorInfos.clear();
-    if (sourcePath == null) {
-      throw new ArgumentError("sourcePath cannot be null");
-    }
-    var sourceFile = new JavaFile(sourcePath);
-    var librarySource = new FileBasedSource.con1(contentCache, sourceFile);
-    // resolve library
-    prepareAnalysisContext(sourceFile);
-    var libraryElement = context.computeLibraryElement(librarySource);
-    // prepare source and errors
-    prepareSources(libraryElement);
-    prepareErrors();
-  }
+  if (errorCollector.hasErrors) throw errorCollector.group;
 
-  /// Returns the maximal [ErrorSeverity] of the recorded errors.
-  ErrorSeverity get maxErrorSeverity {
-    var status = ErrorSeverity.NONE;
-    for (AnalysisErrorInfo errorInfo in errorInfos) {
-      for (AnalysisError error in errorInfo.errors) {
-        var severity = error.errorCode.errorSeverity;
-        status = status.max(severity);
-      }
-    }
-    return status;
-  }
+  return unit;
+}
 
-  void prepareAnalysisContext(JavaFile sourceFile) {
-    List<UriResolver> resolvers = [new DartUriResolver(sdk), new FileUriResolver()];
-    // may be add package resolver
-    {
-      var packageDirectory = getPackageDirectoryFor(sourceFile);
-      if (packageDirectory != null) {
-        resolvers.add(new PackageUriResolver([packageDirectory]));
-      }
-    }
-    sourceFactory = new SourceFactory.con1(contentCache, resolvers);
-    context = AnalysisEngine.instance.createAnalysisContext();
-    context.sourceFactory = sourceFactory;
+/// Converts an AST node representing a string literal into a [String].
+String stringLiteralToString(StringLiteral literal) {
+  if (literal is AdjacentStrings) {
+    return literal.strings.map(stringLiteralToString).join();
+  } else if (literal is SimpleStringLiteral) {
+    return literal.value;
+  } else {
+    throw new ArgumentError("Can't convert $literal to a Dart string.");
   }
+}
 
-  /// Fills [sources].
-  void prepareSources(LibraryElement library) {
-    var units = new Set<CompilationUnitElement>();
-    var libraries = new Set<LibraryElement>();
-    addLibrarySources(library, libraries, units);
-  }
+/// A simple error listener that collects errors into an [AnalysisErrorGroup].
+class _ErrorCollector extends AnalysisErrorListener {
+  final _errors = <AnalysisError>[];
 
-  void addCompilationUnitSource(CompilationUnitElement unit, Set<LibraryElement> libraries,
-      Set<CompilationUnitElement> units) {
-    if (unit == null || units.contains(unit)) {
-      return;
-    }
-    units.add(unit);
-    sources.add(unit.source);
-  }
+  /// Whether any errors where collected.
+  bool get hasErrors => !_errors.isEmpty;
 
-  void addLibrarySources(LibraryElement library, Set<LibraryElement> libraries,
-      Set<CompilationUnitElement> units) {
-    if (library == null || libraries.contains(library)) {
-      return;
-    }
-    libraries.add(library);
-    // may be skip library
-    {
-      UriKind uriKind = library.source.uriKind;
-      // Optionally skip package: libraries.
-      if (!options.showPackageWarnings && uriKind == UriKind.PACKAGE_URI) {
-        return;
-      }
-      // Optionally skip SDK libraries.
-      if (!options.showSdkWarnings && uriKind == UriKind.DART_URI) {
-        return;
-      }
-    }
-    // add compilation units
-    addCompilationUnitSource(library.definingCompilationUnit, libraries, units);
-    for (CompilationUnitElement child in library.parts) {
-      addCompilationUnitSource(child, libraries, units);
-    }
-    // add referenced libraries
-    for (LibraryElement child in library.importedLibraries) {
-      addLibrarySources(child, libraries, units);
-    }
-    for (LibraryElement child in library.exportedLibraries) {
-      addLibrarySources(child, libraries, units);
-    }
-  }
+  /// The group of errors collected.
+  AnalyzerErrorGroup get group =>
+    new AnalyzerErrorGroup.fromAnalysisErrors(_errors);
 
-  /// Fills [errorInfos].
-  void prepareErrors() {
-    for (Source source in sources) {
-      var sourceErrors = context.getErrors(source);
-      errorInfos.add(sourceErrors);
-    }
-  }
+  _ErrorCollector();
 
-  static JavaFile getPackageDirectoryFor(JavaFile sourceFile) {
-    JavaFile sourceFolder = sourceFile.getParentFile();
-    JavaFile packagesFolder = new JavaFile.relative(sourceFolder, "packages");
-    if (packagesFolder.exists()) {
-      return packagesFolder;
-    }
-    return null;
-  }
+  void onError(AnalysisError error) => _errors.add(error);
 }