55 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			55 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
| 'use strict';
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| 
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| Object.defineProperty(exports, "__esModule", {
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|     value: true
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| });
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| exports.default = compose;
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| 
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| var _seq = require('./seq.js');
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| 
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| var _seq2 = _interopRequireDefault(_seq);
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| 
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| function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
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| 
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| /**
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|  * Creates a function which is a composition of the passed asynchronous
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|  * functions. Each function consumes the return value of the function that
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|  * follows. Composing functions `f()`, `g()`, and `h()` would produce the result
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|  * of `f(g(h()))`, only this version uses callbacks to obtain the return values.
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|  *
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|  * If the last argument to the composed function is not a function, a promise
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|  * is returned when you call it.
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|  *
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|  * Each function is executed with the `this` binding of the composed function.
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|  *
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|  * @name compose
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|  * @static
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|  * @memberOf module:ControlFlow
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|  * @method
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|  * @category Control Flow
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|  * @param {...AsyncFunction} functions - the asynchronous functions to compose
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|  * @returns {Function} an asynchronous function that is the composed
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|  * asynchronous `functions`
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|  * @example
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|  *
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|  * function add1(n, callback) {
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|  *     setTimeout(function () {
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|  *         callback(null, n + 1);
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|  *     }, 10);
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|  * }
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|  *
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|  * function mul3(n, callback) {
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|  *     setTimeout(function () {
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|  *         callback(null, n * 3);
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|  *     }, 10);
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|  * }
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|  *
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|  * var add1mul3 = async.compose(mul3, add1);
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|  * add1mul3(4, function (err, result) {
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|  *     // result now equals 15
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|  * });
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|  */
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| function compose(...args) {
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|     return (0, _seq2.default)(...args.reverse());
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| }
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| module.exports = exports.default; |