Tutorial by Examples: co

Cofree (Writer w) ~~ WriterT w Stream

Given data Writer w a = Writer w a we have data Cofree (Writer w) a = a :< (w, Cofree (Writer w) a) which is equivalent to data Stream (w,a) = Stream (w,a) (Stream (w,a)) which can properly be written as WriterT w Stream with data WriterT w m a = WriterT (m (w,a))

Haskell Language • Common functors as the base of cofree comonads

Cofree (Either e) ~~ NonEmptyT (Writer e)

Given data Either e a = Left e | Right a we have data Cofree (Either e) a = a :< Left e | a :< Right (Cofree (Either e) a) which is isomorphic to data Hospitable e a = Sorry_AllIHaveIsThis_Here'sWhy a e | EatThis a (Hospitable e a) or, if yo...

Haskell Language • Common functors as the base of cofree comonads

Cofree (Reader x) ~~ Moore x

Given data Reader x a = Reader (x -> a) we have data Cofree (Reader x) a = a :< (x -> Cofree (Reader x) a) which is isomorphic to data Plant x a = Plant a (x -> Plant x a) aka Moore machine.

Haskell Language • Common functors as the base of cofree comonads

A) Fixed content's size :

The size of the content will be the same as that of its ScrollPane container. import javafx.scene.control.ScrollPane; //Import the ScrollPane import javafx.scene.control.ScrollPane.ScrollBarPolicy; //Import the ScrollBarPolicy import javafx.scene.layout.Pane; ScrollPane scrollpane; Pane con...

javafx • ScrollPane

B) Dynamic content's size :

The size of the content will change depending on the added elements that exceed the content limits in both axes (horizontal and vertical) that can be seen by moving through the view. import javafx.scene.control.ScrollPane; //Import the ScrollPane import javafx.scene.control.ScrollPane.ScrollBar...

javafx • ScrollPane

Open Terminal in current Xcode project folder

Xcode have ability to run any script with hotkey. Here is example how to assign hotkey ⌘+⌥+⌃+⇧+T to open Terminal app in current project folder. Create bash script and save it in some folder #!/bin/bash # Project Name: $XcodeProject # Project Dir: $XcodeProjectPath # Workspace Dir: $X...

Xcode • Customizing Xcode IDE

Consider Writing More Documentation, Tests, Logging and Assertions Instead of Using a Debugger

Debugging takes time and effort. Instead of chasing bugs with a debugger, consider spending more time on making your code better by: Write and run Tests. Python and Django have great builtin testing frameworks - that can be used to test your code much faster than manually with a debugger. Writ...

Django • Debugging

Sample server code

constexpr const size_t addressSize = sizeof(sockaddr_in); constexpr const uint16_t defaultPort = 80; // The port you want to use int serverSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); sockaddr_in serverAddress, clientAddress; memset(&serverAddress, 0, addressSize); serverAddress....

sockets • C++ Sockets

Orbit Controls

An Orbit Camera is one that allows the user to rotate around a central point, but while keeping a particular axis locked. This is extremely popular because it prevents the scene from getting "tilted" off-axis. This version locks the Y (vertical) axis, and allows users to Orbit, Zoom, and P...

three.js • Camera Controls in Three.js

Custom Camera Control - Mouse-based Sliding

Here's an example of a custom camera controller. This reads the position of the mouse within the client window, and then slides the camera around as if it were following the mouse on the window. index.html <html> <head> <title>Three.js Custom Mouse Camera Control Ex...

three.js • Camera Controls in Three.js

Using Package Protected Scope

In Java if you don't provide an access modifier the default scope for variables is package-protected level. This means that classes can access the variables of other classes within the same package as if those variables were publicly available. package foo.bar public class ExampleClass { do...

Java Language • Packages

Component

For an easier transition to Angular 2, it's recommended to use Component, available since Angular 1.5.8 myModule.ts import { MyModuleComponent } from "./components/myModuleComponent"; import { MyModuleService } from "./services/MyModuleService"; angular .module("m...

TypeScript • TypeScript with AngularJS

Navigator component

Navigator works for both IOS and android. import React, { Component } from 'react'; import { Text, Navigator, TouchableHighlight } from 'react-native'; export default class NavAllDay extends Component { render() { return ( <Navigator initialRoute={{ title: 'Awesome Sc...

react-native • Routing

Basic plugin which change color of text to green.

// plugin initialization $.fn.greenify = function() { // within the function you can use any of the jQuery methods // and `this` context refers to jQuery object this.css( "color", "green" ); }; // apply plugin $( "a" ).greenify();

jquery-plugins • Getting started with jquery-plugins

Binding function context

5.1 Every function has a bind method, which will create a wrapped function that will call it with the correct context. See here for more information. var monitor = { threshold: 5, check: function(value) { if (value > this.threshold) { this.display("Value is too high!&quot...

JavaScript • Context (this)

this in constructor functions

When using a function as a constructor, it has a special this binding, which refers to the newly created object: function Cat(name) { this.name = name; this.sound = "Meow"; } var cat = new Cat("Tom"); // is a Cat object cat.sound; // Returns "Meow" var ca...

JavaScript • Context (this)

Colour Notation

There are various ways to use colours in Processing since Processing is very flexible with colour formats. RGB and RGBA This is the standard RGB(A) notation and the default color mode. The first three colour values (red, green, blue) range from 0 to 255. For example, the below example is the colou...

processing • Colours in Processing

Convert tabs to spaces and spaces to tabs

You can convert tabs to spaces by doing the following: First check that expandtab is switched off :set noexpandtab Then :retab! which replaces spaces of a certain length with tabs If you enable expandtab again :set expandtab then and run the :retab! command then all the tabs becomes spaces...

vim • Whitespace

Watch kit controller (WKInterfaceController)

import WatchConnectivity var watchSession : WCSession? override func awake(withContext context: Any?) { super.awake(withContext: context) // Configure interface objects here. startWatchSession() } func startWatchSession(){ if(WCSession....

iOS • WCSessionDelegate

Creating Custom Error Messages in Model and in Controller

Let's say that you have the following class: public class PersonInfo { public int ID { get; set; } [Display(Name = "First Name")] [Required(ErrorMessage = "Please enter your first name!")] public string FirstName{ get; set; } [Display(Name = "L...

asp.net-mvc • Model validation