chaining

method chaining including class constructor

由 半城伤御伤魂 提交于 2019-12-04 08:50:28
I'm trying to implement method chaining in C++, which turns out to be quite easy if the constructor call of a class is a separate statement, e.g: Foo foo; foo.bar().baz(); But as soon as the constructor call becomes part of the method chain, the compiler complains about expecting ";" in place of "." immediately after the constructor call: Foo foo().bar().baz(); I'm wondering now if this is actually possible in C++. Here is my test class: class Foo { public: Foo() { } Foo& bar() { return *this; } Foo& baz() { return *this; } }; I also found an example for "fluent interfaces" in C++ ( http://en

Adding attributes in chaining way in dplyr package

由 醉酒当歌 提交于 2019-12-04 07:20:32
Is there any way to add an attribute using chaining sequence code operator %>% from dplyr package? > library(dplyr) > iris %>% + attr( "date") = Sys.Date() Error in iris %>% attr("date") = Sys.Date() : could not find function "%>%<-" > Thanks for respone. You can also consider setattr from "data.table": library(dplyr) library(data.table) names(attributes(iris)) # [1] "names" "row.names" "class" iris %>% setattr(., "date", Sys.Date()) names(attributes(iris)) # [1] "names" "row.names" "class" "date" attributes(I2)$date # [1] "2014-09-04" Of course, no chaining is actually required for something

Combining promises and chaining

由 蹲街弑〆低调 提交于 2019-12-04 05:43:57
问题 Is there a good design pattern for utilizing promises, while still supporting chaining? For example, let's say that we have something like: function Foobar() { this.foo = function() { console.log('foo'); return this; }; this.bar = function () { console.log('bar'); return this; }; } var foobar = new Foobar(); foobar.foo().bar(); If instead we change the methods to use promises, e.g. function Foobar() { this.foo = function() { var self = this; return new Promise(function (resolve, reject) {

Effects of method chaining

由 自闭症网瘾萝莉.ら 提交于 2019-12-04 04:30:58
I know the benefits of chaining within PHP but lets say we have this following situation $Mail = new MailClass("mail") ->SetFrom("X") ->SetTo("X") ->SetSubject("X") ->AddRecipient("X") ->AddRecipient("X") ->AddRecipient("X") ->AddRecipient("X") ->AddRecipient("X") ->AddRecipient("X") ->Send(); Are there any issues with returning and reusing the object over and over again, issues such as speed or failure to follow best Practises Also a good read on this if your new to Fluent-Interface's: Martin Fowler on Fluent-Interfaces I Fully understand that it doesn't have to be programmed this way, and

How does chained methods execute in java?

由 早过忘川 提交于 2019-12-04 02:22:06
问题 Here is my code : result = method1().method2().method3(); I would like to know the execution hierarchy of the above code/statement 回答1: Just go through the following points. Determine what the leftmost method call will return (let’s call it x). Use x as the object invoking the second (from the left) method. If there are only two chained methods, the result of the second method call is the expression's result. If there is a third method, the result of the second method call is used to invoke

How to achieve arbitrary chain on function call in javascript? [duplicate]

由 人走茶凉 提交于 2019-12-04 01:24:16
问题 This question already has answers here : Variadic curried sum function (12 answers) Closed 4 years ago . I have written code to achieve sum(1)(2) //3 the code looks like: function sum(a) { return function(b) { return a+b } } But I didn't work out the second question, which is how to achieve any arbitrary number of chain function call like: sum(1)(2) == 3 sum(5)(-1)(2) == 6 sum(6)(-1)(-2)(-3) == 0 sum(0)(1)(2)(3)(4)(5) == 15 回答1: Normally you'd do something like this: var add = function(a,b){

BeanUtils not works for chain setter

由 自作多情 提交于 2019-12-04 00:55:33
问题 e.g. class tester { @Test public void testBeanUtils() throws InvocationTargetException, IllegalAccessException, NoSuchMethodException { Stranger stranger = new Stranger(); BeanUtils.setProperty(stranger,"name","wener"); BeanUtils.setProperty(stranger,"xname","xwener"); BeanUtils.setProperty(stranger,"yname","ywener"); System.out.println(stranger); } @Data// lombok annotation generate all setter and getter public static class Stranger { @Accessors(chain = true)// generate chained setter String

Java 8 streams group by 3 fields and aggregate by sum and count produce single line output

由 僤鯓⒐⒋嵵緔 提交于 2019-12-03 09:49:45
I know there a similar questions asked in the forum but none of them seem to be addressing my problem fully. Now I'm very new to Java 8, so please bear with me. I have a list of Products, for example: Input: name category type cost prod1 cat2 t1 100.23 prod2 cat1 t2 50.23 prod1 cat1 t3 200.23 prod3 cat2 t1 150.23 prod1 cat2 t1 100.23 Output: Single line (name, category, type) summing the cost and count of products. Product { public String name; public String category; public String type; public int id; public double cost; } I need to group this by name, category and type and produce a single

Create chained methods in node.js?

由 为君一笑 提交于 2019-12-03 08:00:35
Is it possible to create chained methods that are asynchronous like this in node.js File.create('file.jpg').rename('renamed.jpg').append('Hello World') That is to say non-blocking. You basically want to abstract the asynchronous nature of the file-handling operations on your API. It can be done, I would recommend you to give a look to the following article: Asynchronous method queue chaining in JavaScript The article was written by Dustin Diaz, who currently works on the @anywhere JavaScript API , and he does exactly what you want, using a using a simple Queue implementation, a fluent

Write a jQuery Plugin that return values

由 谁都会走 提交于 2019-12-03 07:48:59
I'm writing a jQuery plugin that stores some data in some cases. I'd like to write it in a very flexible way, where I'll can change an input parameter to obtain some value that were stored by the plugin. Explanation: When I call $("#any").myPlugin() , my plugin initializes creating a div and some a inside. Clicking on an a will store it .index() using the .data() method. If I call $("#any").myPlugin("getSelection") then I would like to get the value stored with .data() . What I'd tried: (function ($) { $.fn.myPlugin = function (action) { if (action == null) action = "initialize"; return this
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