110 lines
3.0 KiB
JavaScript
110 lines
3.0 KiB
JavaScript
// Copyright 2012 The Closure Library Authors. All Rights Reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS-IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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/**
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* @fileoverview Defines an interface that represents a Result.
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*/
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goog.provide('goog.result.Result');
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/**
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* A Result object represents a value returned by an asynchronous
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* operation at some point in the future (e.g. a network fetch). This is akin
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* to a 'Promise' or a 'Future' in other languages and frameworks.
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*
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* @interface
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*/
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goog.result.Result = function() {};
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/**
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* Attaches handlers to be called when the value of this Result is available.
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* Handlers are called in the order they were added by wait.
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*
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* @param {!function(this:T, !goog.result.Result)} handler The function called
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* when the value is available. The function is passed the Result object as
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* the only argument.
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* @param {T=} opt_scope Optional scope for the handler.
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* @template T
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*/
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goog.result.Result.prototype.wait = function(handler, opt_scope) {};
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/**
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* The States this object can be in.
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*
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* @enum {string}
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*/
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goog.result.Result.State = {
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/** The operation was a success and the value is available. */
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SUCCESS: 'success',
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/** The operation resulted in an error. */
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ERROR: 'error',
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/** The operation is incomplete and the value is not yet available. */
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PENDING: 'pending'
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};
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/**
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* @return {!goog.result.Result.State} The state of this Result.
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*/
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goog.result.Result.prototype.getState = function() {};
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/**
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* @return {*} The value of this Result. Will return undefined if the Result is
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* pending or was an error.
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*/
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goog.result.Result.prototype.getValue = function() {};
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/**
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* @return {*} The error slug for this Result. Will return undefined if the
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* Result was a success, the error slug was not set, or if the Result is
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* pending.
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*/
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goog.result.Result.prototype.getError = function() {};
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/**
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* Cancels the current Result, invoking the canceler function, if set.
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*
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* @return {boolean} Whether the Result was canceled.
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*/
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goog.result.Result.prototype.cancel = function() {};
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/**
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* @return {boolean} Whether this Result was canceled.
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*/
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goog.result.Result.prototype.isCanceled = function() {};
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/**
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* The value to be passed to the error handlers invoked upon cancellation.
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* @constructor
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* @extends {Error}
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*/
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goog.result.Result.CancelError = function() {
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// Note that this does not derive from goog.debug.Error in order to prevent
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// stack trace capture and reduce the amount of garbage generated during a
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// cancel() operation.
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};
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goog.inherits(goog.result.Result.CancelError, Error);
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