Learn Canvas, Elixir and Immutable

These videos include the introductory steps to writing your first Elixir function and beginning to understand some key concepts in Elixir that make it unique. 

Some of those concepts include:
- the Mix build tool
- project structure
- collections of functions written in modules
- function *arity*
- pattern matching and common uses for it
- the pipe operator

Elixir is a dynamic, functional language designed for building scalable and maintainable applications.

Elixir leverages the Erlang VM, known for running low-latency, distributed and fault-tolerant systems, while also being successfully used in web development and the embedded software domain.

elixir

Getting Started with Elixir

A <canvas> element provides scripts with a resolution-dependent bitmap canvas, which can be used for rendering graphs, game graphics, or other visual images on the fly.

canvas

Learn some of the different ways you can affect the graphical content that you are drawing to a canvas. We'll cover global alpha, global composite operations and shadows.

Canvas Effects

With the HTML `canvas` you can easily draw text as well as graphics. Let's take a look at basic text manipulation on the canvas.

Drawing Text on Canvas

In this lesson, we cover several different ways to animate graphics drawn to Canvas.

Animating with Canvas

When drawing on the HTML5 canvas element, your fills aren't limited to flat colors. You can use gradients to get smoothly blended color fills on your drawn elements.

Gradient Fills on the HTML5 Canvas

Transformations can change the default canvas coordinate system and create complex drawings with much less code.

Canvas Transformations

In this lesson, listening for and handling mouse and keyboard events in Canvas is covered.

Listening for Mouse and Keyboard Events with HTML Canvas

The HTML Canvas element allows us to access powerful drawing APIs from JavaScript. In this lesson, the first in a series, we will learn about `<canvas>`, and get ready to start drawing.

Introduction to the HTML Canvas element

Now that we have an HTML5 canvas to draw on, let's take a look at drawing simple lines and rectangles with JavaScript

Drawing Paths - Lines and Rectangles

When drawing on your HTML canvas in JavaScript, you aren't restricted to straight lines. Using curves and arcs you are able to create smooth curved lines.

Drawing Paths - Curves and Arcs

Immutable.js provides many Persistent Immutable data structures including: List, Stack, Map, OrderedMap, Set, OrderedSet and Record.

immutable

There are lots of techniques for accessing data kept in your Lists. In this lesson, we will compare how data stored in collections can be accessed directly in both standard Arrays and ImmutableJS Lists. We will also look at how to find data inside an Immutable List using the `findEntry` and `findIndex` methods.

Get items in an ImmutableJS List

You aren't limited to boring black lines when drawing on the HTML5 canvas element. Using styles, you can program interesting colorful images with JavaScript.

Drawing Styles on HTML5 Canvas

In this lesson, you'll learn how to read and write individual pixel color values from a canvas.

Canvas and Pixels

The reduce function in ImmutableJS allows you to transform and create new data from an existing data structure. In this example, we will do some math and calculate a sum based on data in an ImmutableJS Map.

Calculate a sum using reduce in ImmutableJS

In addition to vector drawing, you can draw bitmap images into a canvas, and also retrieve a bitmap based on the content in a canvas.

HTML Canvas and Images

The key to being productive with Immutable JS is understanding how to update values that are nested. Using `setIn` you can place a new value directly into an existing or new path. If you need access to the previous value before setting the new one, you can use `updateIn` instead. `updateIn`  accepts the same path lookups as `setIn`, but gives you a callback function instead so that you can use the previous value however you wish and return an updated version.

Updating nested values with ImmutableJS

ImmutableJS reduce functions can be nested to get data out of complex data structures. In this example, we will create an Immutable List from an Immutable Map that is nested inside of an Immutable List that is itself nested inside of an Immutable Map.

Create a list with nested reduce functions in ImmutableJS

By utilizing immutable data structures, we can write code that is easier to reason about, avoid mutation-related bugs, reduce complexity, and even gain some performance benefits along the way.

Before diving too far into Facebook's [Immutable.js](https://facebook.github.io/immutable-js/) library, let's take a moment to examine some of the pains and obstacles that mutable data structures present. 

We'll take a brief glimpse at putting the Immutable "List" data structure to work by example. We will convert our usage of Javascript's native `Array` to use [Immutable.List](https://facebook.github.io/immutable-js/docs/#/List) in order to address a mutation-related "bug" caused by multiple objects "sharing" a mutable structure (array) by reference.

Immutable.js: Introduction - Easing the Pains of Mutability

In this lesson we'll look at some of the differences between standard JavaScript Arrays and Immutable Lists. We'll create Immutable.JS Lists from scratch, as well as by converting regular Arrays. We will also compare and contrast the `push` and `concat` methods between both types of collection.

Create an immutable List using Immutable.js

The pipe operator is an easy to use and powerful feature of Elixir. It takes the output from the expression on the left, and automatically passes it as the first argument to the function on the right. This is especially useful when chaining together multiple function calls or data transformations. Using the pipe operator results in code that's easier to read, write and refactor.

Chain Function Calls with the Pipe Operator in Elixir

The `canvas` element exposes a 2d context which allows you to draw lines using the `moveTo`, `lineTo`, and `stroke` api. You can combine this with Mouse events to make a simple drawing app.

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