The Happy Lambda
With Membership
Minimum paid price

The Happy Lambda

Functional Programming in Ruby

About the Book

About the Author

Arne Brasseur
Arne Brasseur

Arne is a developer, public speaker, programming coach and open-source contributor. With a passion for both human and programming languages, he has spent the last decade teaching and exploring the finer points of Ruby, LISP, Haskell, Mandarin Chinese, and others.

When not hopping conferences or Pacific islands, he can be found at his home base in Berlin, brewing fine teas while pondering the future of open-source and the web.

Table of Contents

  • 1. Publish early, publish often
    • 1.1 Changelog
  • 2. Introduction
    • 2.1 Evocation
  • 3. Functional Programming
    • 3.1 What vs how
    • 3.2 Functions as first class citizens
    • 3.3 Higher Order Functions
    • 3.4 Lack of mutable state
    • 3.5 Pure functions
    • 3.6 Strict and Lazy Evaluation
    • 3.7 Pros and Cons
  • 4. Building blocks
    • 4.1 Methods and Functions
    • 4.2 Iterators, Enumerables and Enumerators
    • 4.3 Lambdas / procs / blocks
    • 4.4 Lazy enumerators (to be written)
  • 5. Patterns
    • 5.1 Value Object
    • 5.2 Function Object (to be written)
    • 5.3 Functional Core, Imperative Shell (to be written)
    • 5.4 Collections
  • 6. Making Ruby More Functional
    • 6.1 Block and Lambda Arguments
    • 6.2 Converting to Proc
    • 6.3 Dropping the Ampersands
    • 6.4 Function Composition
  • 7. Runtime support
    • 7.1 Applicative vs Lazy evaluation (to be written)
    • 7.2 Frozen (string) literals (to be written)
    • 7.3 Tail recursion / tail call optimization (to be written)
    • 7.4 Garbage Collection (to be written)
  • 8. Glossary

The Leanpub 60 Day 100% Happiness Guarantee

Within 60 days of purchase you can get a 100% refund on any Leanpub purchase, in two clicks.

Now, this is technically risky for us, since you'll have the book or course files either way. But we're so confident in our products and services, and in our authors and readers, that we're happy to offer a full money back guarantee for everything we sell.

You can only find out how good something is by trying it, and because of our 100% money back guarantee there's literally no risk to do so!

So, there's no reason not to click the Add to Cart button, is there?

See full terms...

80% Royalties. Earn $16 on a $20 book.

We pay 80% royalties. That's not a typo: you earn $16 on a $20 sale. If we sell 5000 non-refunded copies of your book or course for $20, you'll earn $80,000.

(Yes, some authors have already earned much more than that on Leanpub.)

In fact, authors have earnedover $13 millionwriting, publishing and selling on Leanpub.

Learn more about writing on Leanpub

Free Updates. DRM Free.

If you buy a Leanpub book, you get free updates for as long as the author updates the book! Many authors use Leanpub to publish their books in-progress, while they are writing them. All readers get free updates, regardless of when they bought the book or how much they paid (including free).

Most Leanpub books are available in PDF (for computers) and EPUB (for phones, tablets and Kindle). The formats that a book includes are shown at the top right corner of this page.

Finally, Leanpub books don't have any DRM copy-protection nonsense, so you can easily read them on any supported device.

Learn more about Leanpub's ebook formats and where to read them

Write and Publish on Leanpub

You can use Leanpub to easily write, publish and sell in-progress and completed ebooks and online courses!

Leanpub is a powerful platform for serious authors, combining a simple, elegant writing and publishing workflow with a store focused on selling in-progress ebooks.

Leanpub is a magical typewriter for authors: just write in plain text, and to publish your ebook, just click a button. (Or, if you are producing your ebook your own way, you can even upload your own PDF and/or EPUB files and then publish with one click!) It really is that easy.

Learn more about writing on Leanpub