Type check constant variable declarations.

pkg/analyzer/lib/src/generated/error.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.
 
 // This code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 
 library engine.error;
 
 import 'dart:collection';
@@ skipping 438 matching lines @@
    * argument <i>e<sub>i</sub></i><i>, 1 &lt;= i &lt;= n</i>
    *
    * 12.14.2 Binding Actuals to Formals: Let <i>T<sub>i</sub></i> be the static type of
    * <i>a<sub>i</sub></i>, let <i>S<sub>i</sub></i> be the type of <i>p<sub>i</sub>, 1 &lt;= i &lt;=
    * n+k</i> and let <i>S<sub>q</sub></i> be the type of the named parameter <i>q</i> of <i>f</i>.
    * It is a static warning if <i>T<sub>j</sub></i> may not be assigned to <i>S<sub>j</sub>, 1 &lt;=
    * j &lt;= m</i>.
    */
   static const CheckedModeCompileTimeErrorCode MAP_VALUE_TYPE_NOT_ASSIGNABLE = const CheckedModeCompileTimeErrorCode.con1('MAP_VALUE_TYPE_NOT_ASSIGNABLE', 4, "The element type '{0}' cannot be assigned to the map value type '{1}'");
 
+  /**
+   * 12.11.2 Const: It is a compile-time error if evaluation of a constant object results in an
+   * uncaught exception being thrown.
+   */
+  static const CheckedModeCompileTimeErrorCode VARIABLE_TYPE_MISMATCH =
+      const CheckedModeCompileTimeErrorCode.con1(
+          'VARIABLE_TYPE_MISMATCH',
+          5,
+          "The object type '{0}' cannot be assigned to a variable of type '{1}'");

[Brian Wilkerson, 2014/10/10 21:23:45]

"variable" --> "const variable"?

It might be more obvious to the user what's going on if the message indicates
that this is only an error because the variable is a 'const'. Or possibly
something explicit about the fact that there will be a run-time exception. (My
concern is that users will look at the types in question and be confused because
super types can be assigned to subtypes.

[Paul Berry, 2014/10/10 21:56:38]

Good point.  I've added a TODO comment for now.  I'll loop back and think about
how to wordsmith the messages once I've discovered all the situations where we
need to report errors like this.

+
   static const List<CheckedModeCompileTimeErrorCode> values = const [
       CONST_CONSTRUCTOR_PARAM_TYPE_MISMATCH,
       CONST_FIELD_INITIALIZER_NOT_ASSIGNABLE,
       LIST_ELEMENT_TYPE_NOT_ASSIGNABLE,
       MAP_KEY_TYPE_NOT_ASSIGNABLE,
-      MAP_VALUE_TYPE_NOT_ASSIGNABLE];
+      MAP_VALUE_TYPE_NOT_ASSIGNABLE,
+      VARIABLE_TYPE_MISMATCH];
 
   /**
    * The template used to create the message to be displayed for this error.
    */
   final String message;
 
   /**
    * The template used to create the correction to be displayed for this error, or `null` if
    * there is no correction information for this error.
    */
@@ skipping 3708 matching lines @@
 
   @override
   String get message => "{0}";
 
   @override
   ErrorType get type => ErrorType.TODO;
 
   @override
   String get uniqueName => "${runtimeType.toString()}.${name}";
 }