Tutorial by Examples: io

Sometimes it is useful to create union types with only one case to implement record-like types: type Point = Point of float * float let point1 = Point(0.0, 3.0) let point2 = Point(-2.5, -4.0) These become very useful because they can be decomposed via pattern matching in the same way as tu...

If you don't know which options you should use, you may be interested in the :options command. This will open a split with all Vim options listed and with their current value displayed. There are 26 sections to display all options you can try. e.g. 4 displaying text scroll number of lines t...

Singleton Objects Scala supports static members, but not in the same manner as Java. Scala provides an alternative to this called Singleton Objects. Singleton objects are similar to a normal class, except they can not be instantiated using the new keyword. Below is a sample singleton class: object...

Information Inheritance allows you to derive a new class from an existing class. You do this using the INHERITING FROM addition in the CLASS subclass DEFINITION INHERITING FROM superclass. statement. The new class subclass inherits all of the components of the existing class superclass. The n...

During development, when certain code paths must be prevented from the reach of control flow, you may use assert(0) to indicate that such a condition is erroneous: switch (color) { case COLOR_RED: case COLOR_GREEN: case COLOR_BLUE: break; default: assert(0); ...

string outsidetext = "I am outside of bracket"; string.Format("{{I am in brackets!}} {0}", outsidetext); //Outputs "{I am in brackets!} I am outside of bracket"

Linux kernel source code can be found in https://www.kernel.org/ Download extract and enter to the kernel directory Type these commands step by steps in your terminal.(Choose the appropriate version you needed instead of linux-4.7.tar.gz ) wget http://www.kernel.org/pub/linux/kernel/v4.7/linux-4....

Any permission required by your application to access a protected part of the API or to interact with other applications must be declared in your AndroidManifest.xml file. This is done using the <uses-permission /> tag. Syntax <uses-permission android:name="string" android...

Be careful with semicolons. Following example if (x > a); a = x; actually means: if (x > a) {} a = x; which means x will be assigned to a in any case, which might not be what you wanted originally. Sometimes, missing a semicolon will also cause an unnoticeable problem: if (i &lt...

Detailed instructions on getting ibm-midrange set up or installed.

Collection initialization syntax can be used when instantiating any class which implements IEnumerable and has a method named Add which takes a single parameter. In previous versions, this Add method had to be an instance method on the class being initialized. In C#6, it can also be an extension me...

It is also possible to assign a supervision strategy to these actors with the following: superviseWith(OneForOneStrategy() { case e: Exception if e.getMessage == "hello" ⇒ Stop case _: Exception ⇒ Resume })

Open Control Panel -> Programs and Features, choose the Visual Studio 2015 item, and then choose the Change button. In the setup wizard for Visual Studio, choose the Modify button. In the list of optional features to install, select the HTML/JavaScript (Apache Cordova) checkbox, c...

In Visual Studio, choose Tools->Extensions and Updates. In the Updates tab of the Extensions and Updates dialog box, choose Product Updates. If an update for Visual Studio Tools for Apache appears, select it, and then choose the Update button.

Angular supports three types of expressions in the ng-class directive. 1. String <span ng-class="MyClass">Sample Text</span> Specifying an expression that evaluates to a string tells Angular to treat it as a $scope variable. Angular will check the $scope and look for a va...

Initialize a UICollectionView with a CGRect frame: Swift: let collection = UICollectionView(frame: CGRect(x: 0, y: 0, width: 200, height: 21)) Objective C: UICollectionView *collection = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 0, 200, 21)]; You can also create a UICollectionVi...

Every collection view must have a Datasource object. The Datasource object is the content that your app will display within the UICollectionView. At a minimum, all Datasource objects must implement the collectionView:numberOfItemsInSection: and collectionView:cellForItemAtIndexPath: methods. Requir...

Functions are first-class citizens in Kotlin. You can obtain a reference on it using double colons and then pass it to another function: fun isPositive(x: Int) = x > 0 val numbers = listOf(-2, -1, 0, 1, 2) println(numbers.filter(::isPositive)) // [1, 2]

To obtain a Java's Class object from Kotlin's KClass use the .java extension property: val stringKClass: KClass<String> = String::class val c1: Class<String> = stringKClass.java val c2: Class<MyClass> = MyClass::class.java The latter example will be optimized by the compile...

The conventional connect syntax that uses SIGNAL and SLOT macros works entirely at runtime, which has two drawbacks: it has some runtime overhead (resulting also in binary size overhead), and there's no compile-time correctness checking. The new syntax addresses both issues. Before checking the synt...