Tutorial by Examples: co

Defining the list of Ints trait IntList { ... } class Cons(val head: Int, val tail: IntList) extends IntList { ... } class Nil extends IntList { ... } but what if we need to define the list of Boolean, Double etc? Defining generic list trait List[T] { def isEmpty: Boolean def head:...

Say, you have a dataset consisting of names and email addresses. Now in another dataset, you just have the email address and wish to find the appropriate first name that belongs to that email address. The MATCH function returns the appropriate row the email is at, and the INDEX function selects i...

Usually the case when one wants to change a field type to another, for instance the original collection may have "numerical" or "date" fields saved as strings: { "name": "Alice", "salary": "57871", "dob": "198...

After you got the Location object from FusedAPI, you can easily acquire Address information from that object. private Address getCountryInfo(Location location) { Address address = null; Geocoder geocoder = new Geocoder(getActivity(), Locale.getDefault()); String errorMessage; Li...

If you are attempting to get an Angular2 site running on your Windows work computer at XYZ MegaCorp the chances are that you are having problems getting through the company proxy. There are (at least) two package managers that need to get through the proxy: NPM Typings For NPM you need to ad...

You have a few options when it comes to logging in with Meteor. The most common method is using accounts for Meteor. Accounts-password If you want users to be able to create and register on your site, you can use accounts-password. Install the package using meteor add accounts-password. To creat...

@Configuration // @Lazy - For all Beans to load lazily public class AppConf { @Bean @Lazy public Demo demo() { return new Demo(); } }

@Component @Lazy public class Demo { .... .... } @Component public class B { @Autowired @Lazy // If this is not here, Demo will still get eagerly instantiated to satisfy this request. private Demo demo; ....... }

i=0 while read -r line; do i=$((i+1)) done < file echo $i With a file containing: Alpha Beta Gamma Delta Epsilon The above script prints: 5

Allow change user unique ID if account is compromised with a new user&password login To invalidate tokens when user changes their password or permissions, sign the token with a hash of those fields. If any of these field change, any previous tokens automatically fail to verify. The down...

This will download libpng from the official "git" repository and build it in your "libpng" directory. git clone https://github.com/glennrp/libpng.git libpng cd libpng ./autogen.sh ./configure [--prefix=/path] make install where "/path" points to the installation...

One helpful case is to have the action run a block of code. In Swift: let node = SKSpriteNode(imageNamed: "image") let actionBlock = SKAction.runBlock({ //Do what you want here if let gameScene = node.scene as? GameScene { gameScene.score += 5 } }) node.runActi...

If you want to use docker for rails app, and use database, you need to know that all the data in the docker container will be destroyed (unless you configure the container specifically for keeping data) Sometimes, you need to create a docker container with an application and attach it to an old con...

To select an element by an HTML attribute that contains a specified value use the css locator pattern [attribute*=value] //selects the first element with href value that contains'cont' element(by.css('[href*="cont"]')); //selects the first element with tag h1 and class attribute that...

Sometimes users from other regions than English-speaking have problems with encoding while for example programming a php project. It can be, that the server has another encoding then UTF-8, and if someone want to create a php project in UTF-8 on this server, his text might be shown incorrect. Examp...

One of most common use cases of Gitflow Initialize repo and define branches $ git flow init # if you use default setup, you'll define six types of branches: # # main branches (lives forever) # # 1. master: for production releases # 2. develop: for "next ...

$rootScope.$on listeners will remain in memory if you navigate to another controller. This will create a memory leak if the controller falls out of scope. Don't angular.module('app').controller('badExampleController', badExample); badExample.$inject = ['$scope', '$rootScope']; function badExam...

You cannot access any GUI components from the BackgroudWorker. For example if you try to do something like this Private Sub BackgroundWorker1_DoWork(sender As Object, e As DoWorkEventArgs) TextBox1.Text = "Done" End Sub you will receive a runtime error saying that "Cross-thr...

<Exec Command="echo Hello World" />

In order to enable writing more complex UI tests the UIAutomatorViewer is needed. The tool located at /tools/ makes a fullscreen screenshot including the layouts of the currently displayed views. See the subsequent picture to get an idea of what is shown: For the UI tests we are looking for resou...