text: /**
   * @license
   * Copyright Google Inc. All Rights Reserved.
   *
   * Use of this source code is governed by an MIT-style license that can be
   * found in the LICENSE file at https://angular.io/license
   */
  import { OptionalMetadata, Provider, SkipSelfMetadata } from '../../di';
  import { ListWrapper } from '../../facade/collection';
  import { BaseException } from '../../facade/exceptions';
  import { getTypeNameForDebugging, isBlank, isPresent } from '../../facade/lang';
  /**
   * A repository of different iterable diffing strategies used by NgFor, NgClass, and others.
   * @ts2dart_const
   * @stable
   */
  export class IterableDiffers {
      /*@ts2dart_const*/
      constructor(factories) {
          this.factories = factories;
      }
      static create(factories, parent) {
          if (isPresent(parent)) {
              var copied = ListWrapper.clone(parent.factories);
              factories = factories.concat(copied);
              return new IterableDiffers(factories);
          }
          else {
              return new IterableDiffers(factories);
          }
      }
      /**
       * Takes an array of {@link IterableDifferFactory} and returns a provider used to extend the
       * inherited {@link IterableDiffers} instance with the provided factories and return a new
       * {@link IterableDiffers} instance.
       *
       * The following example shows how to extend an existing list of factories,
             * which will only be applied to the injector for this component and its children.
             * This step is all that's required to make a new {@link IterableDiffer} available.
       *
       * ### Example
       *
       * ```
       * @Component({
       *   viewProviders: [
       *     IterableDiffers.extend([new ImmutableListDiffer()])
       *   ]
       * })
       * ```
       */
      static extend(factories) {
          return new Provider(IterableDiffers, {
              useFactory: (parent) => {
                  if (isBlank(parent)) {
                      // Typically would occur when calling IterableDiffers.extend inside of dependencies passed
                      // to
                      // bootstrap(), which would override default pipes instead of extending them.
                      throw new BaseException('Cannot extend IterableDiffers without a parent injector');
                  }
                  return IterableDiffers.create(factories, parent);
              },
              // Dependency technically isn't optional, but we can provide a better error message this way.
              deps: [[IterableDiffers, new SkipSelfMetadata(), new OptionalMetadata()]]
          });
      }
      find(iterable) {
          var factory = this.factories.find(f => f.supports(iterable));
          if (isPresent(factory)) {
              return factory;
          }
          else {
              throw new BaseException(`Cannot find a differ supporting object '${iterable}' of type '${getTypeNameForDebugging(iterable)}'`);
          }
      }
  }
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