Support for NamedExpression(s) as constructor initializer arguments.

pkg/analyzer/lib/src/summary/summarize_const_expr.dart

 // Copyright (c) 2016, 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 serialization.summarize_const_expr;
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/element/type.dart' show DartType;
 import 'package:analyzer/src/summary/format.dart';
@@ skipping 27 matching lines @@
   }
   throw new StateError('Unexpected initializer type ${node.runtimeType}');
 }
 
 /**
  * Instances of this class keep track of intermediate state during
  * serialization of a single constant [Expression].
  */
 abstract class AbstractConstExprSerializer {
   /**
-   * See [UnlinkedConstBuilder.isInvalid].
+   * See [UnlinkedConstBuilder.isValidConst].
    */
   bool isValidConst = true;
 
   /**
+   * See [UnlinkedConstBuilder.nmae].
+   */
+  String name = null;
+
+  /**
    * See [UnlinkedConstBuilder.operations].
    */
   final List<UnlinkedConstOperation> operations = <UnlinkedConstOperation>[];
 
   /**
    * See [UnlinkedConstBuilder.assignmentOperators].
    */
   final List<UnlinkedExprAssignOperator> assignmentOperators =
       <UnlinkedExprAssignOperator>[];
 
@@ skipping 21 matching lines @@
    * Return `true` if a constructor initializer expression is being serialized
    * and the given [name] is a constructor parameter reference.
    */
   bool isConstructorParameterName(String name);
 
   /**
    * Serialize the given [expr] expression into this serializer state.
    */
   void serialize(Expression expr) {
     try {
+      if (expr is NamedExpression) {
+        NamedExpression namedExpression = expr;
+        name = namedExpression.name.label.name;
+        expr = namedExpression.expression;
+      }
       _serialize(expr);
     } on StateError {
       isValidConst = false;
     }
   }
 
   /**
    * Serialize the given [annotation] into this serializer state.
    */
   void serializeAnnotation(Annotation annotation);
@@ skipping 41 matching lines @@
     return serializeType(type?.type, type?.name, type?.typeArguments);
   }
 
   /**
    * Return the [UnlinkedConstBuilder] that corresponds to the state of this
    * serializer.
    */
   UnlinkedConstBuilder toBuilder() {
     return new UnlinkedConstBuilder(
         isValidConst: isValidConst,
+        name: name,
         operations: operations,
         assignmentOperators: assignmentOperators,
         ints: ints,
         doubles: doubles,
         strings: strings,
         references: references);
   }
 
   /**
    * Push the operation for the given assignable [expr].
@@ skipping 406 matching lines @@
         expr = (expr as PrefixedIdentifier).prefix;
       } else if (expr is PropertyAccess) {
         expr = (expr as PropertyAccess).target;
       } else {
         return false;
       }
     }
     return false;
   }
 }