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| 'use strict';
const asyncJs = require('async');
function aa(callback) {
setTimeout(() => {
callback(undefined, 1);
}, 1000);
}
function bb(lastValue, callback) {
setTimeout(() => {
callback(undefined, lastValue + 2);
}, 2000);
}
function cc(lastValue, callback) {
setTimeout(() => {
callback(undefined, lastValue + 3);
}, 3000);
}
const pa = function() {
return new Promise(function(resolve) {
aa(function(err, value) {
resolve(value);
});
});
}
const pb = function(lastValue) {
return new Promise(function(resolve) {
bb(lastValue, function(err, value) {
resolve(value);
});
});
}
const pc = function(lastValue) {
return new Promise(function(resolve) {
cc(lastValue, function(err, value) {
resolve(value);
});
});
}
const util = function(func) {
return function() {
const args = Array.from(arguments);
return new Promise(function(resolve, reject) {
args.push(function(err, result) {
if(err) {
return reject(err);
}
resolve(result);
});
func.apply(null, args);
});
}
}
const ppa = util(aa);
const ppb = util(bb);
const ppc = util(cc);
|
