Removed ArgResult in lib/docgen.dart and removed top level variables.

pkg/docgen/lib/docgen.dart

Index: pkg/docgen/lib/docgen.dart
diff --git a/pkg/docgen/lib/docgen.dart b/pkg/docgen/lib/docgen.dart
index 5159c05b421e89a71b489771e52f4cb81bb6a850..dd5ae22b2663fbe0bd14208532c462bd02d033c5 100644
--- a/pkg/docgen/lib/docgen.dart
+++ b/pkg/docgen/lib/docgen.dart
@@ -19,7 +19,6 @@ import 'dart:io';
 import 'dart:json';
 import 'dart:async';
 
-import 'package:args/args.dart';
 import 'package:logging/logging.dart';
 import 'package:markdown/markdown.dart' as markdown;
 import 'package:pathos/path.dart' as path;
@@ -51,47 +50,35 @@ MemberMirror _currentMember;
 /// Resolves reference links in doc comments. 
 markdown.Resolver linkResolver;
 
-/// Package directory of directory being analyzed. 
-String packageDir;
-
-bool outputToYaml;
-bool outputToJson;
-bool includePrivate;
-/// State for whether imported SDK libraries should also be outputted.
-bool includeSdk;
-/// State for whether all SDK libraries should be outputted. 
-bool parseSdk;
-
 /**
  * Docgen constructor initializes the link resolver for markdown parsing.
  * Also initializes the command line arguments. 
+ * 
+ * [packageRoot] is the packages directory of the directory being analyzed. 
+ * If [includeSdk] is 'true', then any SDK libraries explicitly imported will 
+ * also be documented. 
+ * If [parseSdk] is 'true', then all Dart SDK libraries will be documented. 
+ * This option is useful when only the SDK libraries are needed. 
  */
-void docgen(ArgResults argResults) {  
-  _setCommandLineArguments(argResults);
+void docgen(List<String> files, {String packageRoot, bool outputToYaml: true, 
+  bool includePrivate: false, bool includeSdk: false, bool parseSdk: false}) {  
+  if (packageRoot == null && !parseSdk) {
+    packageRoot = _findPackageRoot(files.first);
+  }
+  logger.info('Package Root: ${packageRoot}');
   
   linkResolver = (name) => 
       fixReference(name, _currentLibrary, _currentClass, _currentMember);
   
-  getMirrorSystem(argResults.rest).then((MirrorSystem mirrorSystem) {
-    if (mirrorSystem.libraries.values.isEmpty) {
-      throw new StateError('No Library Mirrors.');
-    }
-    _documentLibraries(mirrorSystem.libraries.values);
-  });
-}
-
-void _setCommandLineArguments(ArgResults argResults) {
-  outputToYaml = argResults['yaml'] || argResults['output-format'] == 'yaml';
-  outputToJson = argResults['json'] || argResults['output-format'] == 'json';
-  if (outputToYaml && outputToJson) {
-    throw new ArgumentError('Cannot have contradictory output flags.');
-  }
-  outputToYaml = outputToYaml || !outputToJson;
-  includePrivate = argResults['include-private'];
-  parseSdk = argResults['parse-sdk'];
-  includeSdk = parseSdk || argResults['include-sdk'];
-  packageDir = argResults['package-root'];
-  if (packageDir != null) logger.info('Package Root: ${packageDir}');
+  getMirrorSystem(files, packageRoot, parseSdk: parseSdk)
+    .then((MirrorSystem mirrorSystem) {
+      if (mirrorSystem.libraries.isEmpty) {
+        throw new StateError('No library mirrors were created.');
+      }
+      _documentLibraries(mirrorSystem.libraries.values, 
+          includeSdk: includeSdk, includePrivate: includePrivate, 
+          outputToYaml: outputToYaml);
+    });
 }
 
 List<String> _listLibraries(List<String> args) {
@@ -113,12 +100,6 @@ List<String> _listLibraries(List<String> args) {
 
 List<String> _listDartFromDir(String args) {
   var files = listDir(args, recursive: true);
-  if (packageDir == null) {
-    packageDir = files.firstWhere((f) => 
-        f.endsWith('/pubspec.yaml'), orElse: () => '');
-    if (packageDir != '') packageDir = path.dirname(packageDir) + '/packages';
-    logger.info('Package Directory: $packageDir');
-  }
   // To avoid anaylzing package files twice, only files with paths not 
   // containing '/packages' will be added. The only exception is if the file to
   // analyze already has a '/package' in its path. 
@@ -127,6 +108,17 @@ List<String> _listDartFromDir(String args) {
       ..forEach((lib) => logger.info('Added to libraries: $lib'));
 }
 
+String _findPackageRoot(String directory) {
+  var files = listDir(directory, recursive: true);
+  // Return '' means that there was no pubspec.yaml and therefor no packageRoot. 
+  String packageRoot = files.firstWhere((f) => 
+      f.endsWith('/pubspec.yaml'), orElse: () => '');
+  if (packageRoot != '') {
+    packageRoot = path.dirname(packageRoot) + '/packages';
+  }
+  return packageRoot;
+}
+
 List<String> _listSdk() {
   var sdk = new List<String>();
   LIBRARIES.forEach((String name, LibraryInfo info) {
@@ -142,7 +134,8 @@ List<String> _listSdk() {
  * Analyzes set of libraries by getting a mirror system and triggers the 
  * documentation of the libraries. 
  */
-Future<MirrorSystem> getMirrorSystem(List<String> args) {
+Future<MirrorSystem> getMirrorSystem(List<String> args, String packageRoot, 
+    {bool parseSdk:false}) {
   var libraries = !parseSdk ? _listLibraries(args) : _listSdk();
   if (libraries.isEmpty) throw new StateError('No Libraries.');
   // DART_SDK should be set to the root of the SDK library. 
@@ -156,7 +149,7 @@ Future<MirrorSystem> getMirrorSystem(List<String> args) {
     logger.info('SDK Root: ${sdkRoot}');
   }
   
-  return _getMirrorSystemHelper(libraries, sdkRoot, packageRoot: packageDir);
+  return _analyzeLibraries(libraries, sdkRoot, packageRoot: packageRoot);
 }
 
 // TODO(janicejl): Should make docgen fail gracefully, or output a friendly
@@ -167,7 +160,7 @@ Future<MirrorSystem> getMirrorSystem(List<String> args) {
  * Analyzes set of libraries and provides a mirror system which can be used 
  * for static inspection of the source code.
  */
-Future<MirrorSystem> _getMirrorSystemHelper(List<String> libraries,
+Future<MirrorSystem> _analyzeLibraries(List<String> libraries,
       String libraryRoot, {String packageRoot}) {
   SourceFileProvider provider = new SourceFileProvider();
   api.DiagnosticHandler diagnosticHandler =
@@ -197,12 +190,14 @@ Future<MirrorSystem> _getMirrorSystemHelper(List<String> libraries,
 /**
  * Creates documentation for filtered libraries.
  */
-void _documentLibraries(List<LibraryMirror> libraries) {
+void _documentLibraries(List<LibraryMirror> libraries, 
+    {bool includeSdk:false, bool includePrivate:false, bool 
+     outputToYaml:true}) {
   libraries.forEach((lib) {
     // Files belonging to the SDK have a uri that begins with 'dart:'.
     if (includeSdk || !lib.uri.toString().startsWith('dart:')) {
-      var library = generateLibrary(lib);
-      _outputLibrary(library);
+      var library = generateLibrary(lib, includePrivate: includePrivate);
+      _writeLibraryToFile(library, outputToYaml);
     }
   });
   // Outputs a text file with a list of files available after creating all 
@@ -211,22 +206,24 @@ void _documentLibraries(List<LibraryMirror> libraries) {
   _writeToFile(listDir("docs").join('\n'), 'library_list.txt');
 }
 
-Library generateLibrary(dart2js.Dart2JsLibraryMirror library) {
+Library generateLibrary(dart2js.Dart2JsLibraryMirror library, 
+  {bool includePrivate:false}) {
   _currentLibrary = library;
   var result = new Library(library.qualifiedName, _getComment(library),
-      _getVariables(library.variables), _getMethods(library.functions),
-      _getClasses(library.classes));
+      _getVariables(library.variables, includePrivate), 
+      _getMethods(library.functions, includePrivate),
+      _getClasses(library.classes, includePrivate));
   logger.fine('Generated library for ${result.name}');
   return result;
 }
 
-void _outputLibrary(Library result) {
-  if (outputToJson) {
-    _writeToFile(stringify(result.toMap()), '${result.name}.json');
-  } 
+void _writeLibraryToFile(Library result, bool outputToYaml) {
   if (outputToYaml) {
     _writeToFile(getYamlString(result.toMap()), '${result.name}.yaml');
-  }
+  } else {
+    _writeToFile(stringify(result.toMap()), '${result.name}.json');
+  } 
+  
 }
 
 /**
@@ -275,8 +272,11 @@ markdown.Node fixReference(String name, LibraryMirror currentLibrary,
 /**
  * Returns a map of [Variable] objects constructed from inputted mirrors.
  */
-Map<String, Variable> _getVariables(Map<String, VariableMirror> mirrorMap) {
+Map<String, Variable> _getVariables(Map<String, VariableMirror> mirrorMap, 
+    bool includePrivate) {
   var data = {};
+  // TODO(janicejl): When map to map feature is created, replace the below with 
+  // a filter. Issue(#9590).
   mirrorMap.forEach((String mirrorName, VariableMirror mirror) {
     if (includePrivate || !mirror.isPrivate) {
       _currentMember = mirror;
@@ -291,7 +291,8 @@ Map<String, Variable> _getVariables(Map<String, VariableMirror> mirrorMap) {
 /**
  * Returns a map of [Method] objects constructed from inputted mirrors.
  */
-Map<String, Method> _getMethods(Map<String, MethodMirror> mirrorMap) {
+Map<String, Method> _getMethods(Map<String, MethodMirror> mirrorMap, 
+    bool includePrivate) {
   var data = {};
   mirrorMap.forEach((String mirrorName, MethodMirror mirror) {
     if (includePrivate || !mirror.isPrivate) {
@@ -309,7 +310,8 @@ Map<String, Method> _getMethods(Map<String, MethodMirror> mirrorMap) {
 /**
  * Returns a map of [Class] objects constructed from inputted mirrors.
  */
-Map<String, Class> _getClasses(Map<String, ClassMirror> mirrorMap) {
+Map<String, Class> _getClasses(Map<String, ClassMirror> mirrorMap,
+    bool includePrivate) {
   var data = {};
   mirrorMap.forEach((String mirrorName, ClassMirror mirror) {
     if (includePrivate || !mirror.isPrivate) {
@@ -321,7 +323,8 @@ Map<String, Class> _getClasses(Map<String, ClassMirror> mirrorMap) {
       data[mirrorName] = new Class(mirrorName, mirror.qualifiedName, 
           superclass, mirror.isAbstract, mirror.isTypedef, 
           _getComment(mirror), interfaces.toList(),
-          _getVariables(mirror.variables), _getMethods(mirror.methods), 
+          _getVariables(mirror.variables, includePrivate),
+          _getMethods(mirror.methods, includePrivate), 
           _getAnnotations(mirror));
     }
   });