Tutorial by Examples: io

Pattern matching allows to deconstruct complex values and it is by no way limited to the “outer most” level of the representation of a value. To illustrate this, we implement the function transforming a boolean expression into a boolean expression where all negations are only on atoms, the so calle...

A reference to an option &Option<T> cannot be unwrapped if the type T is not copyable. The solution is to change the option to &Option<&T> using as_ref(). Rust forbids transferring of ownership of objects while the objects are borrowed. When the Option itself is borrowed (&a...

Woocommerce is a plugin for WordPress and can be installed like any other WordPress plugin. WooCommerce can only be installed on self hosted installations of WordPress, it cannot be installed onto a site hosted by the wordpress.com service. If you don't have WordPress installed for your website, fo...

Functions are of the type Function: function example():void { } trace(example is Function); // true They can be referenced by other variables with the type Function: var ref:Function = example; ref(); // ref.call(), ref.apply(), etc. And they can be passed in as arguments for parameters wh...

The C++ approach - new and delete In a language like C++, the application program is responsible for managing the memory used by dynamically allocated memory. When an object is created in the C++ heap using the new operator, there needs to be a corresponding use of the delete operator to dispose o...

Detailed instructions on getting monogame set up or installed.

Declare the AppWidgetProvider class in your application's AndroidManifest.xml file. For example: <receiver android:name="ExampleAppWidgetProvider" > <intent-filter> <action android:name="android.appwidget.action.APPWIDGET_UPDATE" /> </intent-filter&gt...

String concatenation is done simply by writing expressions next to one another without any operator. For example: BEGIN { user = "root" print "Hello "user "!" } will print: Hello root! Note that expressions do not have to be separated by whitespace.

Nine-patch images allow optional definition of the padding lines in the image. The padding lines are the lines on the right and at the bottom. If a View sets the 9-patch image as its background, the padding lines are used to define the space for the View's content (e.g. the text input in an EditTex...

This is MATLAB's long-winded way of saying that it cannot find the function that you're trying to call. There are a number of reasons you could get this error: That function was introduced after your current version of MATLAB The MATLAB online documentation provides a very nice feature which allow...

This example uses a search controller to filter the data inside a table view controller. The search bar is placed inside the navigation bar that the table view is embedded into. Embed a UITableViewController into a UINavigationController to get the UINavigationItem (which contains the navigation ...

It is also possible to create archives of other items than HEAD, such as branches, commits, tags, and directories. To create an archive of a local branch dev: git archive --output=archive-dev.zip --prefix=src-directory-name dev To create an archive of a remote branch origin/dev: git archive --...

Node.js has 3 basic ways to handle exceptions/errors: try-catch block error as the first argument to a callback emit an error event using eventEmitter try-catch is used to catch the exceptions thrown from the synchronous code execution. If the caller (or the caller's caller, ...) used try/ca...

Since Unity 5.2.5 it's possible to use RuntimeInitializeOnLoadMethodAttribute to execute initialization logic bypassing MonoBehaviour order of execution. It provides a way to create more clean and robust implementation: using UnityEngine; sealed class GameDirector : MonoBehaviour { // Beca...

NotificationCompat.Builder mBuilder = (NotificationCompat.Builder) new NotificationCompat.Builder(context) .setSmallIcon(R.drawable.some_small_icon) .setContentTitle("Title") .setContentText("This is a test notification with MAX priority")...

A has_many :through association is often used to set up a many-to-many connection with another model. This association indicates that the declaring model can be matched with zero or more instances of another model by proceeding through a third model. For example, consider a medical practice where p...

A has_one :through association sets up a one-to-one connection with another model. This association indicates that the declaring model can be matched with one instance of another model by proceeding through a third model. For example, if each supplier has one account, and each account is associated...

A has_and_belongs_to_many association creates a direct many-to-many connection with another model, with no intervening model. For example, if your application includes assemblies and parts, with each assembly having many parts and each part appearing in many assemblies, you could declare the models...

We can check the status of migrations by running 3.05.0 rake db:migrate:status 5.0 rails db:migrate:status The output will look like this: Status Migration ID Migration Name -------------------------------------------------- up 20140711185212 Create documentation pages up ...

In order to compile and run SystemVerilog code a tool called a simulator is needed. Most commonly, commercial tools from one of the Big Three EDA companies is used: Cadence Incisive Mentor Graphics QuestaSim Synopsys VCS Other EDA vendors also provide simulators: Aldec Riviera-PRO Xilinx...