Ruby#

Ruby is a delightful programming language designed for programmer happiness 💖.

Yukihiro Matsumoto once presented How Emacs Changed My Life (PDF) which goes into how Emacs and emacs-lisp influenced Matz and the design of the Ruby programming language. Unfortunately, it seems there is not video recording of it. Here’s the Slideshare link for the presentation.

Nice tools:

Ruby Concepts and Ideas#

  • The name of the language is spelled Ruby (not RUBY or ruby) because it is a proper noun (therefore, the first letter is capitalized). ruby is the name of the program we use to run Ruby programs, like ruby -w fib.rb.

  • A mix-in (also spelled mix in) is the including of a module inside a class. We say things like “The Enumerable mix-in module provides…”. See Ruby doc on modules.

Bits and Bytes of Syntax Suggar#

Hash Values#

We can get all the values of a hash by doing this:

>> { one: 1, two: 2 }.map(&:last)
=> [1, 2]

Which is similar to doing hash.values

Map and Hash to Proc to Get Values#

>> h = { one: 1, two: 2 }

>> [:one, :two].map(&h)
=> [1, 2]

With an array of keys, we map over those keys, and turn the hash into a proc😲!

Saw this first in a solution for resistor color duo exercism challenge.

If we define to_proc we can use this trick for any object.

Hash Transform Values and &:next to_proc#

>> {one: 1, two: 2}.transform_values(&:next)
=> {:one=>2, :two=>3}