refactor: add types to top-level fields in change_detection

Also introduced an abstract PipeFactory base class

modules/angular2/src/change_detection/change_detection.js

@@ -1,4 +1,5 @@
 import {DynamicProtoChangeDetector, JitProtoChangeDetector} from './proto_change_detector';
+import {PipeFactory} from './pipes/pipe';
 import {PipeRegistry} from './pipes/pipe_registry';
 import {IterableChangesFactory} from './pipes/iterable_changes';
 import {KeyValueChangesFactory} from './pipes/keyvalue_changes';
@@ -16,7 +17,7 @@ import {List} from 'angular2/src/facade/collection';
  *
  * @exportedAs angular2/pipes
  */
-export var keyValDiff = [
+export var keyValDiff:List<PipeFactory> = [
   new KeyValueChangesFactory(),
   new NullPipeFactory()
 ];
@@ -26,7 +27,7 @@ export var keyValDiff = [
  *
  * @exportedAs angular2/pipes
  */
-export var iterableDiff = [
+export var iterableDiff:List<PipeFactory> = [
   new IterableChangesFactory(),
   new NullPipeFactory()
 ];
@@ -36,12 +37,12 @@ export var iterableDiff = [
  *
  * @exportedAs angular2/pipes
  */
-export var async = [
+export var async:List<PipeFactory> = [
   new AsyncPipeFactory(),
   new NullPipeFactory()
 ];
 
-export var defaultPipes = {
+export var defaultPipes:Map<String, List<PipeFactory>> = {
   "iterableDiff" : iterableDiff,
   "keyValDiff" : keyValDiff,
   "async" : async

modules/angular2/src/change_detection/pipes/async_pipe.js

@@ -1,6 +1,6 @@
 import {Observable, ObservableWrapper} from 'angular2/src/facade/async';
-import {isBlank, isPresent} from 'angular2/src/facade/lang';
+import {isBlank, isPresent, CONST} from 'angular2/src/facade/lang';
-import {Pipe, WrappedValue} from './pipe';
+import {Pipe, WrappedValue, PipeFactory} from './pipe';
 import {ChangeDetectorRef} from '../change_detector_ref';
 
 /**
@@ -52,7 +52,7 @@ export class AsyncPipe extends Pipe {
   onDestroy():void {
     if (isPresent(this._subscription)) {
       this._dispose();
-    };
+    }
   }
 
   transform(obs:Observable):any {
@@ -101,7 +101,12 @@ export class AsyncPipe extends Pipe {
  *
  * @exportedAs angular2/pipes
  */
-export class AsyncPipeFactory {
+export class AsyncPipeFactory extends PipeFactory {
+  @CONST()
+  constructor() {
+    super();
+  }
+
   supports(obs):boolean {
     return ObservableWrapper.isObservable(obs);
   }

modules/angular2/src/change_detection/pipes/iterable_changes.js

@@ -1,3 +1,4 @@
+import {CONST} from 'angular2/src/facade/lang';
 import {
   isListLikeIterable,
   iterateListLike,
@@ -14,9 +15,14 @@ import {
   looseIdentical,
 } from 'angular2/src/facade/lang';
 
-import {WrappedValue, Pipe} from './pipe';
+import {WrappedValue, Pipe, PipeFactory} from './pipe';
+
+export class IterableChangesFactory extends PipeFactory {
+  @CONST()
+  constructor() {
+    super();
+  }
 
-export class IterableChangesFactory {
   supports(obj):boolean {
     return IterableChanges.supportsObj(obj);
   }

modules/angular2/src/change_detection/pipes/keyvalue_changes.js

@@ -1,12 +1,17 @@
 import {ListWrapper, MapWrapper, StringMapWrapper} from 'angular2/src/facade/collection';
-import {stringify, looseIdentical, isJsObject} from 'angular2/src/facade/lang';
+import {stringify, looseIdentical, isJsObject, CONST} from 'angular2/src/facade/lang';
 
-import {WrappedValue, Pipe} from './pipe';
+import {WrappedValue, Pipe, PipeFactory} from './pipe';
 
 /**
  * @exportedAs angular2/pipes
  */
-export class KeyValueChangesFactory {
+export class KeyValueChangesFactory extends PipeFactory {
+  @CONST()
+  constructor() {
+    super();
+  }
+
   supports(obj):boolean {
     return KeyValueChanges.supportsObj(obj);
   }

modules/angular2/src/change_detection/pipes/null_pipe.js

@@ -1,10 +1,15 @@
-import {isBlank} from 'angular2/src/facade/lang';
+import {isBlank, CONST} from 'angular2/src/facade/lang';
-import {Pipe, WrappedValue} from './pipe';
+import {Pipe, WrappedValue, PipeFactory} from './pipe';
 
 /**
  * @exportedAs angular2/pipes
  */
-export class NullPipeFactory {
+export class NullPipeFactory extends PipeFactory {
+  @CONST()
+  constructor() {
+    super();
+  }
+
   supports(obj):boolean {
     return NullPipe.supportsObj(obj);
   }

modules/angular2/src/change_detection/pipes/pipe.js

@@ -1,3 +1,5 @@
+import {ABSTRACT, BaseException, CONST} from 'angular2/src/facade/lang';
+
 /**
  * Indicates that the result of a {@link Pipe} transformation has changed even though the reference has not changed.
  *
@@ -55,3 +57,22 @@ export class Pipe {
   onDestroy() {}
   transform(value:any):any {return null;}
 }
+
+@ABSTRACT()
+export class PipeFactory {
+  @CONST()
+  constructor() {
+  }
+
+  supports(obs):boolean {
+    return _abstract();
+  }
+
+  create(cdRef):Pipe {
+    return _abstract();
+  }
+}
+
+function _abstract() {
+  return new BaseException('This method is abstract');
+}