Downward inference

lib/src/options.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.
 
 /// Set of flags and options passed to the compiler
 library dev_compiler.src.options;
 
 import 'dart:io';
 
 import 'package:args/args.dart';
@@ skipping 49 matching lines @@
 
 // TODO(vsm): Merge RulesOptions and TypeOptions
 /// Options used by our RestrictedRules.
 class RulesOptions extends TypeOptions {
   /// Whether to allow casts in constant contexts.
   final bool allowConstCasts;
 
   /// Whether to use covariant generics
   final bool covariantGenerics;
 
+  /// Whether to infer types downwards from local context
+  final bool inferDownwards;
+  static const inferDownwardsDefault = true;
+
   /// Whether to inject casts between Dart assignable types.
   final bool relaxedCasts;
 
   /// Whether to use static types for code generation.
   final bool ignoreTypes;
 
   /// Whether to wrap closures for compatibility.
   final bool wrapClosures;
 
   RulesOptions({this.allowConstCasts: true, this.covariantGenerics: true,
-      this.relaxedCasts: true, this.ignoreTypes: false,
-      this.wrapClosures: true});
+      this.inferDownwards: inferDownwardsDefault, this.relaxedCasts: true,
+      this.ignoreTypes: false, this.wrapClosures: true});
 }
 
 class JSCodeOptions {
   /// Whether to emit the source map files.
   final bool emitSourceMaps;
 
   JSCodeOptions({this.emitSourceMaps: true});
 }
 
 /// General options used by the dev compiler.
@@ skipping 73 matching lines @@
   final bool useMultiPackage;
 
   /// Package root when resolving 'package:' urls the standard way.
   @override
   final String packageRoot;
 
   /// List of paths used for the multi-package resolver.
   @override
   final List<String> packagePaths;
 
+  /// Whether to infer types downwards from local context
+  @override
+  final bool inferDownwards;
+
   /// Whether to infer return types and field types from overriden members.
   @override
   final bool inferFromOverrides;
 
   /// Whether to infer types for consts and static fields by looking at
   /// identifiers on the RHS.
   @override
   final bool inferTransitively;
 
   /// Restrict inference of fields and top-levels to those that are final and
@@ skipping 23 matching lines @@
   final String runtimeDir;
 
   CompilerOptions({this.allowConstCasts: true, this.checkSdk: false,
       this.dumpInfo: false, this.dumpInfoFile, this.dumpSrcDir,
       this.forceCompile: false, this.formatOutput: false,
       this.cheapTestFormat: false, this.ignoreTypes: false,
       this.wrapClosures: true, this.outputDir, this.outputDart: false,
       this.useColors: true, this.covariantGenerics: true,
       this.relaxedCasts: true, this.useMultiPackage: false,
       this.packageRoot: 'packages/', this.packagePaths: const <String>[],
+      this.inferDownwards: RulesOptions.inferDownwardsDefault,
       this.inferFromOverrides: ResolverOptions.inferFromOverridesDefault,
       this.inferTransitively: ResolverOptions.inferTransitivelyDefault,
       this.onlyInferConstsAndFinalFields: ResolverOptions.onlyInferConstAndFinalFieldsDefault,
       this.nonnullableTypes: TypeOptions.NONNULLABLE_TYPES, this.help: false,
       this.useMockSdk: false, this.dartSdkPath, this.logLevel: Level.SEVERE,
       this.emitSourceMaps: true, this.entryPointFile: null,
       this.serverMode: false, this.host: 'localhost', this.port: 8080,
       this.runtimeDir});
 }
 
@@ skipping 35 matching lines @@
       ignoreTypes: args['ignore-types'],
       wrapClosures: args['wrap-closures'],
       outputDart: args['dart-gen'],
       outputDir: outputDir,
       covariantGenerics: args['covariant-generics'],
       relaxedCasts: args['relaxed-casts'],
       useColors: useColors,
       useMultiPackage: args['use-multi-package'],
       packageRoot: args['package-root'],
       packagePaths: args['package-paths'].split(','),
+      inferDownwards: args['infer-downwards'],
       inferFromOverrides: args['infer-from-overrides'],
       inferTransitively: args['infer-transitively'],
       onlyInferConstsAndFinalFields: args['infer-only-finals'],
       nonnullableTypes: optionsToList(args['nonnullable'],
           defaultValue: TypeOptions.NONNULLABLE_TYPES),
       help: args['help'],
       useMockSdk: args['mock-sdk'],
       dartSdkPath: sdkPath,
       logLevel: logLevel,
       emitSourceMaps: args['source-maps'],
@@ skipping 16 matching lines @@
       help: 'Use covariant generics', defaultsTo: true)
   ..addFlag('ignore-types',
       help: 'Ignore types during codegen', defaultsTo: false)
   ..addFlag('wrap-closures', help: 'wrap closures implicitly', defaultsTo: true)
   ..addFlag('relaxed-casts',
       help: 'Cast between Dart assignable types', defaultsTo: true)
   ..addOption('nonnullable',
       abbr: 'n',
       help: 'Comma separated string of non-nullable types',
       defaultsTo: null)
+  ..addFlag('infer-downwards',
+      help: 'Infer types downwards from local context',
+      defaultsTo: RulesOptions.inferDownwardsDefault)
   ..addFlag('infer-from-overrides',
       help: 'Infer unspecified types of fields and return types from\n'
       'definitions in supertypes',
       defaultsTo: ResolverOptions.inferFromOverridesDefault)
   ..addFlag('infer-transitively',
       help: 'Infer consts/fields from definitions in other libraries',
       defaultsTo: ResolverOptions.inferTransitivelyDefault)
   ..addFlag('infer-only-finals',
       help: 'Do not infer non-const or non-final fields',
       defaultsTo: ResolverOptions.onlyInferConstAndFinalFieldsDefault)
@@ skipping 84 matching lines @@
     // The pub-cache directory is two levels up, but we verify that the layout
     // looks correct.
     if (path.basename(dir) != 'dev_compiler') return null;
     dir = path.dirname(dir);
     if (path.basename(dir) != 'global_packages') return null;
     dir = path.dirname(dir);
     return path.join(dir, cacheDir, 'lib', 'runtime');
   }
   return null;
 }