Downwards inference. This adds support to the resolver for downwards

pkg/analyzer/lib/src/task/strong/checker.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.
 
 // TODO(jmesserly): this was ported from package:dev_compiler, and needs to be
 // refactored to fit into analyzer.
 library analyzer.src.task.strong.checker;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/src/generated/ast.dart';
@@ skipping 449 matching lines @@
     // checking in SwitchStatement shouldn't be necessary.
     node.visitChildren(this);
   }
 
   @override
   void visitListLiteral(ListLiteral node) {
     var type = rules.provider.dynamicType;
     if (node.typeArguments != null) {
       var targs = node.typeArguments.arguments;
       if (targs.length > 0) type = targs[0].type;
+    } else if (node.staticType != null && node.staticType is InterfaceType) {

[Brian Wilkerson, 2015/12/01 22:31:09]

You can remove "node.staticType != null && " (it's implied by the is check).

[Leaf, 2015/12/01 23:39:24]

Done.

+      InterfaceType listT = node.staticType;
+      var targs = listT.typeArguments;
+      if (targs != null && targs.length > 0) type = targs[0];
     }
     var elements = node.elements;
     for (int i = 0; i < elements.length; i++) {
       checkArgument(elements[i], type);
     }
     super.visitListLiteral(node);
   }
 
   @override
   void visitMapLiteral(MapLiteral node) {
     var ktype = rules.provider.dynamicType;
     var vtype = rules.provider.dynamicType;
     if (node.typeArguments != null) {
       var targs = node.typeArguments.arguments;
       if (targs.length > 0) ktype = targs[0].type;
       if (targs.length > 1) vtype = targs[1].type;
+    } else if (node.staticType != null && node.staticType is InterfaceType) {

[Brian Wilkerson, 2015/12/01 22:31:09]

ditto

[Leaf, 2015/12/01 23:39:24]

Done.

+      InterfaceType mapT = node.staticType;
+      var targs = mapT.typeArguments;
+      if (targs != null) {
+        if (targs.length > 0) ktype = targs[0];
+        if (targs.length > 1) vtype = targs[1];
+      }
     }
     var entries = node.entries;
     for (int i = 0; i < entries.length; i++) {
       var entry = entries[i];
       checkArgument(entry.key, ktype);
       checkArgument(entry.value, vtype);
     }
     super.visitMapLiteral(node);
   }
 
@@ skipping 444 matching lines @@
     }
     // TODO(jmesserly): we may eventually want to record if the whole operation
     // (node) was dynamic, rather than the target, but this is an easier fit
     // with what we used to do.
     DynamicInvoke.set(target, true);
   }
 
   void _recordMessage(StaticInfo info) {
     if (info == null) return;
     var error = info.toAnalysisError();
-
     var severity = error.errorCode.errorSeverity;
     if (severity == ErrorSeverity.ERROR) _failure = true;
     if (severity != ErrorSeverity.INFO || _hints) {
       reporter.onError(error);
     }
 
     if (info is CoercionInfo) {
       // TODO(jmesserly): if we're run again on the same AST, we'll produce the
       // same annotations. This should be harmless. This might go away once
       // CodeChecker is integrated better with analyzer, as it will know that
@@ skipping 66 matching lines @@
       }
     } catch (e) {
       // TODO(sigmund): remove this try-catch block (see issue #48).
     }
     if (baseMethod == null || baseMethod.isStatic) return null;
     return baseMethod.type;
   }
   ;
   return f;
 }