Better runtime type checks.

frog/type.dart

 // Copyright (c) 2011, 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.
 
 class Type implements Named, Hashable {
   final String name;
   bool isTested;
 
+  /**
+   * For core types (int, String, etc) this is the generated type assertion
+   * function (uses JS "typeof"). This field is null for all other types.
+   */
+  String typeCheckCode;
+
   String _jsname;
 
   Member _typeMember;
 
   /** Stubs used to call into this method dynamically. Lazy initialized. */
   Map<String, VarMember> varStubs;
 
   Type(this.name): isTested = false;
 
   void markUsed() {}
@@ skipping 23 matching lines @@
   // TODO(jmesserly): rename to isDynamic?
   bool get isVar() => false;
   bool get isTop() => false;
 
   bool get isObject() => false;
   bool get isString() => false;
   bool get isBool() => false;
   bool get isFunction() => false;
   bool get isList() => false;
   bool get isNum() => false;
+  bool get isInt() => false;
+  bool get isDouble() => false;
   bool get isVoid() => false;
 
   // Strangely Dart treats calls on Function much like calls on var.
   bool get isVarOrFunction() => isVar || isFunction;
 
   /** Gets the $call method for a function type. */
   MethodMember getCallMethod() => null;
 
   /** These types may not be implemented or extended by user code. */
   bool get isClosed() => isString || isBool || isNum || isFunction || isVar;
@@ skipping 105 matching lines @@
    * of the language spec. It's implemented in terms of the << "more specific"
    * operator. The spec is below:
    *
    * A type T is more specific than a type S, written T << S, if one of the
    * following conditions is met:
    *   - T is S.
    *   - T is Bottom.
    *   - S is Dynamic.
    *   - S is a direct supertype of T.
    *   - T is a type variable and S is the upper bound of T.