Tutorial by Examples: ti

readFloat :: IO Float readFloat = fmap read getLine main :: IO () main = do putStr "Type the first number: " first <- readFloat putStr "Type the second number: " second <- readFloat putStrLn $ show first ++ " + " ++ show se...

A bit counter-intuitive to the way most other languages' standard I/O libraries do it, Haskell's isEOF does not require you to perform a read operation before checking for an EOF condition; the runtime will do it for you. import System.IO( isEOF ) eofTest :: Int -> IO () eofTest line = do ...

$ docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 2bc9b1988080 redis "docker-entrypoint.sh" 2 weeks ago Up 2 hours 0.0.0.0:6379->6379/tcp eleph...

To stop a running container: docker stop <container> [<container>...] This will send the main process in the container a SIGTERM, followed by a SIGKILL if it doesn't stop within the grace period. The name of each container is printed as it stops. To start a container which is stoppe...

$ docker images REPOSITORY TAG IMAGE ID CREATED SIZE hello-world latest 693bce725149 6 days ago 967 B postgres 9.5 0f3af79d8673 10 weeks ago 265.7 MB postgres ...

In Google Chrome, you can pause execution without needing to place breakpoints. Pause on Exception: While this button is toggled on, if your program hits an unhandled exception, the program will pause as if it had hit a breakpoint. The button can be found near Execution Controls and is useful for ...

To install MongoDB, follow the steps below: For Mac OS: There are two options for Mac OS: manual install or homebrew. Installing with homebrew: Type the following command into the terminal: $ brew install mongodb Installing manually: Download the latest release here. Ma...

First create an express app: const express = require('express'); const app = express(); Then you can define routes like this: app.get('/someUri', function (req, res, next) {}) That structure works for all HTTP methods, and expects a path as the first argument, and a handler for that path, w...

WiredTiger supports LSM trees to store indexes. LSM trees are faster for write operations when you need to write huge workloads of random inserts. In WiredTiger, there is no in-place updates. If you need to update an element of a document, a new document will be inserted while the old document will...

jQuery.ajax({ url: 'https://api.dropboxapi.com/2/users/get_current_account', type: 'POST', headers: { "Authorization": "Bearer <ACCESS_TOKEN>" }, success: function (data) { console.log(data); }, error: function (error) { ...

You can animate a UIImageView by quickly displaying images on it in a sequence using the UIImageView's animation properties: imageView.animationImages = [UIImage(named: "image1")!, UIImage(named: "image2")!, UIImage(nam...

We use Notification.requestPermission to ask the user if he/she wants to receive notifications from our website. Notification.requestPermission(function() { if (Notification.permission === 'granted') { // user approved. // use of new Notification(...) syntax will now be succe...

After the user has approved a request for permission to send notifications, we can send a simple notification that says Hello to the user: new Notification('Hello', { body: 'Hello, world!', icon: 'url to an .ico image' }); This will send a notification like this: Hello Hello, world!

5 A property's descriptor can be locked so no changes can be made to it. It will still be possible to use the property normally, assigning and retrieving the value from it, but any attempt to redefine it will throw an exception. The configurable property of the property descriptor is used to dis...

5 Treat a property as a combination of two functions, one to get the value from it, and another one to set the value in it. The get property of the property descriptor is a function that will be called to retrieve the value from the property. The set property is also a function, it will be call...

Note that these only work in the developer tools of certain browsers. $_ gives you the value of whatever expression was evaluated last. "foo" // "foo" $_ // "foo" $0 refers to the DOM element currently selected in the Inspector. So if &l...

While object property notation is usually written as myObject.property, this will only allow characters that are normally found in JavaScript variable names, which is mainly letters, numbers and underscore (_). If you need special characters, such as space, ☺, or user-provided content, this is poss...

The function std::find, defined in the <algorithm> header, can be used to find an element in a std::vector. std::find uses the operator== to compare elements for equality. It returns an iterator to the first element in the range that compares equal to the value. If the element in question is...

An array can easily be converted into a std::vector by using std::begin and std::end: C++11 int values[5] = { 1, 2, 3, 4, 5 }; // source array std::vector<int> v(std::begin(values), std::end(values)); // copy array to new vector for(auto &x: v) std::cout << x << &q...

When you start a thread, it will execute until it is finished. Often, at some point, you need to (possibly - the thread may already be done) wait for the thread to finish, because you want to use the result for example. int n; std::thread thread{ calculateSomething, std::ref(n) }; //Doing some...