Book Image

Polished Ruby Programming

By : Jeremy Evans
5 (1)
Book Image

Polished Ruby Programming

5 (1)
By: Jeremy Evans

Overview of this book

Anyone striving to become an expert Ruby programmer needs to be able to write maintainable applications. Polished Ruby Programming will help you get better at designing scalable and robust Ruby programs, so that no matter how big the codebase grows, maintaining it will be a breeze. This book takes you on a journey through implementation approaches for many common programming situations, the trade-offs inherent in each approach, and why you may choose to use different approaches in different situations. You'll start by refreshing Ruby fundamentals, such as correctly using core classes, class and method design, variable usage, error handling, and code formatting. Then you'll move on to higher-level programming principles, such as library design, use of metaprogramming and domain-specific languages, and refactoring. Finally, you'll learn principles specific to web application development, such as how to choose a database and web framework, and how to use advanced security features. By the end of this Ruby programming book, you’ll be a well rounded web developer with a deep understanding of Ruby. While most code examples and principles discussed in the book apply to all Ruby versions, some examples and principles are specific to Ruby 3.0, the latest release at the time of publication.
Table of Contents (23 chapters)
1
Section 1: Fundamental Ruby Programming Principles
8
Section 2: Ruby Library Programming Principles
17
Section 3: Ruby Web Programming Principles

Learning how best to use instance variables

Almost all objects in Ruby support instance variables. As mentioned in Chapter 1, Getting the Most out of Core Classes, the exceptions are the immediate objects: true, false, nil, integer, floats, and symbols. The reason the immediate objects do not support instance variables is that they lack their own identity. Ruby is written in C, and internally to Ruby, all Ruby objects are stored using the VALUE type. VALUE usually operates as a pointer to another, larger location in memory (called the Ruby heap). In that larger location in memory is where instance variables are stored directly, or if that isn't large enough, a pointer to a separate location in memory where they are stored.

Immediate objects are different from all other objects in that they are not pointers, they contain all information about the object in a single location in memory that is the same size as a pointer. This means there is no space for them to contain instance...