Ruby Enumerable and Comparable

Instructions

Fork, clone, branch (training), and bundle install.

Prerequisites

Objectives

By the end of this lesson, students should be able to:

Add Comparable operators to a class.
Add Enumerable methods to a class.

Introduction

We'll explore an important Ruby mechanism for adding behavior to a class: mixins.

The Comparable Module

The Comparable module provide common operators to a class that implements the <=> (spaceship) operator. Let's look at lib/card.rb.

Practice

How do you compare cards?

In your squads create an algorithm to determine which of two cards, if either, is "greater" than the other.

Demo

Adding the spaceship operator to Card.

Practice - A list as a deck of cards

Let's simulate Enumerable methods using a deck of cards. In your squad, one of you will act as the method and another as the block. The third squad member will record the result.

Cards in Ruby

Let's explore the start of writing a card game in Ruby using lib/card.rb and lib/deck.rb.

The Enumerable Module

We'll build our own list using Ruby's Enumerable module.

Code along - Stepped Range

We'll build a new range class that increments by a provided value. The key to creating an Enumerable is a correct implementation of the each method.

MFBrewster/ruby-enumerable-custom