Tutorial by Examples: at

Naming elements of tuples within discriminated unions

When defining discriminated unions you can name elements of tuple types and use these names during pattern matching. type Shape = | Circle of diameter:int | Rectangle of width:int * height:int let shapeIsTenWide = function | Circle(diameter=10) | Rectangle(width=10) -> t...

F# • Discriminated Unions

Installation for Windows with VirtualBox and SSH support

To use Vagrant on Windows platform you need to install virtualization software and an ssh command-line tool first. This example will use freeware VirtualBox and Cygwin. Install VirtualBox Download the latest VirtualBox version from the official download page and run the downloaded file. Note that ...

vagrant • Getting started with vagrant

Date

5 <input type="date" /> A date picker will pop up on screen for you to choose a date. This is not supported in Firefox or Internet Explorer.

HTML • Input Control Elements

DateTime-Local

5 <input type="datetime-local" /> Dependent on browser support, a date and time picker will pop up on screen for you to choose a date and time.

HTML • Input Control Elements

Installation or Setup

Setup for Yii 1.1 Step 1 - downloading Yii Download the Yii framework bundle from the Yii website Inside the downloaded bundle there are 3 folders, namely: demos framework requirements demos, as the name suggests contains a number of demo Yii applications. framework contains the Yii framew...

yii • Getting started with yii

Using XPath

$html = '<html><body><span class="text">Hello, World!</span></body></html>'; $doc = new DOMDocument(); $doc->loadHTML($html); $xpath = new DOMXPath($doc); $span = $xpath->query("//span[@class='text']")->item(0); echo $span-&...

PHP • Parsing HTML

Creating a pure JSON table

To create a pure JSON table you need to provide a single field with the type JSONB: CREATE TABLE mytable (data JSONB NOT NULL); You should also create a basic index: CREATE INDEX mytable_idx ON mytable USING gin (data jsonb_path_ops); At this point you can insert data in to the table and que...

postgresql • JSON Support

Create a Button

Creation of a Button is simple: Button sampleButton = new Button(); This will create a new Button without any text or graphic inside. If you want to create a Button with a text, simply use the constructor that takes a String as parameter (which sets the textProperty of the Button): Button samp...

javafx • Button

Installation of scikit-learn

The current stable version of scikit-learn requires: Python (>= 2.6 or >= 3.3), NumPy (>= 1.6.1), SciPy (>= 0.9). For most installation pip python package manager can install python and all of its dependencies: pip install scikit-learn However for linux systems it is recomm...

scikit-learn • Getting started with scikit-learn

Installation or Setup

The D programming language's standard compiler DMD can run on all major platforms. To install DMD see here. To install by command line you may run the command (found on the D website): curl -fsS https://dlang.org/install.sh | bash -s dmd Package Managers Arch Linux pacman -S dlang Chocolate...

D Language • Getting started with D Language

Formatted strings

Ruby can inject an array of values into a string by replacing any placeholders with the values from the supplied array. "Hello %s, my name is %s!" % ['World', 'br3nt'] # => Hello World, my name is br3nt! The place holders are represented by two %s and the values are supplied by the...

Ruby Language • Strings

Repeat a String n times

Problem: Create a String containing n repetitions of a String s. The trivial approach would be repeatedly concatenating the String final int n = ... final String s = ... String result = ""; for (int i = 0; i < n; i++) { result += s; } This creates n new string instances ...

Java Language • StringBuilder

Installation or Setup

SWI-Prolog Windows and Mac: Download SWI-Prolog at the official website Simply install by following the installer instructions. Linux (PPA): Add the PPA ppa:swi-prolog/stable to your system’s software sources (developers may choose for ppa:swi-prolog/devel) : Open a terminal (Ctrl+...

Prolog Language • Getting started with Prolog Language

Installation or Setup

If you don't have any RubyGems installed, there is still the pre-gem approach to getting software, doing it manually: Download from RubyGems Unpack into a directory and cd there Install with: ruby setup.rb (you may need admin/root privilege) sudo ruby setup.rb For more details...

rubygems • Getting started with rubygems

Pattern Matching with Case Classes

Every case class defines an extractor that can be used to capture the members of the case class when pattern matching: case class Student(name: String, email: String) def matchStudent1(student: Student): String = student match { case Student(name, email) => s"$name has the following...

Scala Language • Pattern Matching

Basic Info and String Concatenation

Strings in JavaScript can be enclosed in Single quotes 'hello', Double quotes "Hello" and (from ES2015, ES6) in Template Literals (backticks) `hello`. var hello = "Hello"; var world = 'world'; var helloW = `Hello World`; // ES2015 / ES6 Strings can be created...

JavaScript • Strings

Set attributed text

// Modify some of the attributes of the attributed string. let attributedText = NSMutableAttributedString(attributedString: textView.attributedText!) // Use NSString so the result of rangeOfString is an NSRange. let text = textView.text! as NSString // Find the range of each element to modif...

iOS • UITextView

UITextViewDelegate methods

Responding to Editing Notifications textViewShouldBeginEditing(_:) textViewDidBeginEditing(_:) textViewShouldEndEditing(_:) textViewDidEndEditing(_:) Responding to Text Changes textView(_:shouldChangeTextIn:replacementText:) textViewDidChange(_:) Responding to URL textView(_: UITe...

iOS • UITextView

Debugging Java code invoked by MATLAB

Overview In order to debug Java classes that are called during MATLAB execution, it is necessary to perform two steps: Run MATLAB in JVM debugging mode. Attach a Java debugger to the MATLAB process. When MATLAB is started in JVM debugging mode, the following message appears in the command wi...

MATLAB Language • Debugging

Custom Operators

Swift supports the creation of custom operators. New operators are declared at a global level using the operator keyword. The operator's structure is defined by three parts: operand placement, precedence, and associativity. The prefix, infix and postfix modifiers are used to start an custom op...

Swift Language • Advanced Operators