Tutorial by Examples: r

Create a file named '.jshintrc' in the root of your app, where package.json is. *Note on windows: create a file named "jshintrc.txt". Then rename it to ".jshintrc." (notice the dot at the end). This is a configuration file. It can for example tell jshint to ignore certain varia...

FRP, or Functional Reactive Programming, has some basic terms which you need to know. Every piece of data can be represented as Observable, which is an asynchronous data stream. The power of FRP is in representation synchronous and asynchronous events as streams, Observables, and providing the same...

RxSwift offers many ways to create an Observable, let's take a look: import RxSwift let intObservale = Observable.just(123) // Observable<Int> let stringObservale = Observable.just("RxSwift") // Observable<String> let doubleObservale = Observable.just(3.14) // Observable&...

You can restart ubuntu from command line. Below is example of restarting ubuntu immediately. sudo reboot You need to have sudo privilege in order to use this command. Another commands with same results are sudo shutdown -r now and sudo init 6.

In some places in Common Lisp, a series of forms are evaluated in order. For instance, in the body of a defun or lambda, or the body of a dotimes. In those cases, writing multiple forms in order works as expected. In a few places, however, such as the then and else parts of an if expressions, onl...

The general purpose special operator progn is used for evaluating zero or more forms. The value of the last form is returned. For instance, in the following, (print 'hello) is evaluated (and its result is ignored), and then 42 is evaluated and its result (42) is returned: (progn (print 'hello...

Often times, it is helpful to evaluate multiple expressions and to return the result from the first or second form rather than the last. This is easy to accomplish using let and, for instance: (let ((form1-result form1)) form2 form3 ;; ... form-n-1 form-n form1-result) Because...

When writing macros that expand into forms that might involve grouping, it is worthwhile spending some time considering what grouping construction to expand into. For definition style forms, for instance, a define-widget macro that will usually appear as a top-level form, and that several defuns, d...

You can use npm install -g to install a package "globally." This is typically done to install an executable that you can add to your path to run. For example: npm install -g gulp-cli If you update your path, you can call gulp directly. On many OSes, npm install -g will attempt to writ...

Node Version Manager (nvm) greatly simplifies the management of Node.js versions, their installation, and removes the need for sudo when dealing with packages (e.g. npm install ...). Fish Shell (fish) "is a smart and user-friendly command line shell for OS X, Linux, and the rest of the family&...

Square Root Use Math.sqrt() to find the square root of a number Math.sqrt(16) #=> 4 Cube Root To find the cube root of a number, use the Math.cbrt() function 6 Math.cbrt(27) #=> 3 Finding nth-roots To find the nth-root, use the Math.pow() function and pass in a fractional expo...

This is a custom JAX-RS @Provider to use Gson as the JSON parser. The example also shows how to use custom Java 8 date/time converters. @Provider @Produces(MediaType.APPLICATION_JSON) @Consumes(MediaType.APPLICATION_JSON) public class JerseyServerGson implements MessageBodyWriter<O...

2005 The following iterates over the characters of the string s. It works similarly for looping over the elements of an array or a set, so long as the type of the loop-control variable (c, in this example) matches the element type of the value being iterated. program ForLoopOnString; {$APPTYPE ...

If you have a modern CPU or graphics card (GPU) inside your machine, chances are you have everything ready for first steps in OpenCL. Finding out if your processor is OpenCL capable can be usually done via the manufacturer's homepage, a good first start is the official documentation at https://www...

When I first started managing the keyboard I would use separate Notifications in each ViewController. Notification Method (Using NSNotification): class ViewController: UIViewController { override func viewDidLoad() { super.viewDidLoad() NSNotificationCenter.defaultCenter().a...

// Get the reference to your ListView ListView listResults = (ListView) findViewById(R.id.listResults); // Set its adapter listResults.setAdapter(adapter); // Enable filtering in ListView listResults.setTextFilterEnabled(true); // Prepare your adapter for filtering adapter.setFilter...

Objects can be centered by using margin: 0 auto; if they are block elements and have a defined width. HTML <div class="containerDiv"> <div id="centeredDiv"></div> </div> <div class="containerDiv"> <p id="centeredPara...

Many tasks require elevated privileges. You can elevate user privileges to Administrator level for your batch runtime using a shortcut: Press alt+ and the batch file to a selected folder to create a shortcut. Right click and select "Properties". Select the "Shortcut&quo...

The following batch file will popup a UAC Prompt allowing you to accept elevated Administrator privileges for the batch session. Add your tasks code to :usercode section of the batch, so they run with elevated privileges. @echo off setlocal EnableDelayedExpansion :: test and acquire admin rights ...

In most scripting languages, if a function call fails, it may throw an exception and stop execution of the program. Bash commands do not have exceptions, but they do have exit codes. A non-zero exit code signals failure, however, a non-zero exit code will not stop execution of the program. This can...