Tutorial by Examples: g

To create a project called helloworld run: stack new helloworld simple This will create a directory called helloworld with the files necessary for a Stack project.

Stackage is a repository for Haskell packages. We can add these packages to a stack project. Adding lens to a project. In a stack project, there is a file called stack.yaml. In stack.yaml there is a segment that looks like: resolver: lts-6.8 Stackage keeps a list of packages for every revision...

When the GADTs extension is enabled, besides regular data declarations, you can also declare generalized algebraic datatypes as follows: data DataType a where Constr1 :: Int -> a -> Foo a -> DataType a Constr2 :: Show a => a -> DataType a Constr3 :: DataType Int A G...

Example uses of $(document).ready(): Attaching event handlers Attach jQuery event handlers $(document).ready(function() { $("button").click(function() { // Code for the click function }); }); Run jQuery code after the page structure is created jQuery(function($) ...

Step 1: Install the SDK You can install the SDK manually or via CocoaPods. The latter option is highly recommended. Put these lines in Podfile: target 'MyApp' do use_frameworks! pod 'FBSDKCoreKit' pod 'FBSDKLoginKit' pod 'FBSDKShareKit' end Run pod install in the terminal and op...

When building a webserver with Express it's often required to serve a combination of dynamic content and static files. For example, you may have index.html and script.js which are static files kept in the file system. It is common to use folder named 'public' to have static files. In this case th...

This program copies a file using readable and a writable stream with the pipe() function provided by the stream class // require the file system module var fs = require('fs'); /* Create readable stream to file in current directory named 'node.txt' Use utf8 encoding Read the data...

Production deployments will vary in many ways, but a standard convention when deploying in production is to define an environment variable called NODE_ENV and set its value to "production". Runtime flags Any code running in your application (including external modules) can check the valu...

Example. It will be replacing the word email to a name in a text file index.txt with simple RegExp replace(/email/gim, 'name') var fs = require('fs'); fs.readFile('index.txt', 'utf-8', function(err, data) { if (err) throw err; var newValue = data.replace(/email/gim, 'name'); ...

app.js const readline = require('readline'); const fs = require('fs'); var file = 'path.to.file'; var linesCount = 0; var rl = readline.createInterface({ input: fs.createReadStream(file), output: process.stdout, terminal: false }); rl.on('line', function (line) { linesCo...

app.js const readline = require('readline'); const fs = require('fs'); var file = 'path.to.file'; var rl = readline.createInterface({ input: fs.createReadStream(file), output: process.stdout, terminal: false }); rl.on('line', function (line) { console.log(line) // print...

The following example shows how to merge two arrays into one associative array, where the key values will be the items of the first array, and the values will be from the second: $array_one = ['key1', 'key2', 'key3']; $array_two = ['value1', 'value2', 'value3']; $array_three = array_combine($ar...

In many environments, you have access to a global console object that contains some basic methods for communicating with standard output devices. Most commonly, this will be the browser's JavaScript console (see Chrome, Firefox, Safari, and Edge for more information). // At its simplest, you can 'l...

The ng-click directive attaches a click event to a DOM element. The ng-click directive allows you to specify custom behavior when an element of DOM is clicked. It is useful when you want to attach click events on buttons and handle them at your controller. This directive accepts an expression wit...

Get Focus Swift textField.becomeFirstResponder() Objective-C [textField becomeFirstResponder]; Resign Swift textField.resignFirstResponder() Objective-C [textField resignFirstResponder];

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F# allows functions to be added as "members" to types when they are defined (for example, Record Types). However F# also allows new instance members to be added to existing types - even ones declared elsewhere and in other .net languages. The following example adds a new instance method D...

F# allow existing types to be extended with new static functions. type System.String with static member EqualsCaseInsensitive (a, b) = String.Equals(a, b, StringComparison.OrdinalIgnoreCase) This new function can be invoked like this: let x = String.EqualsCaseInsensitive("abc", &...

Modules can be used to add new functions to existing Modules and Types. namespace FSharp.Collections module List = let pair item1 item2 = [ item1; item2 ] The new function can then be called as if it was an original member of List. open FSharp.Collections module Testing = le...