| # RSpec matcher to spec delegations. | |
| # | |
| # Usage: | |
| # | |
| # describe Post do | |
| # it { should delegate(:name).to(:author).with_prefix } # post.author_name | |
| # it { should delegate(:month).to(:created_at) } | |
| # it { should delegate(:year).to(:created_at) } | |
| # end |
| # Newbie Programmer | |
| def factorial(x) | |
| if x == 0 | |
| return 1 | |
| else | |
| return x * factorial(x - 1) | |
| end | |
| end | |
| puts factorial(6) | |
| puts factorial(0) |
| source :rubygems | |
| # We are not loading Active Record, nor Active Resources etc. | |
| # We can do this in any app by simply replacing the rails gem | |
| # by the parts we want to use. | |
| gem "actionpack", "~> 3.2" | |
| gem "railties", "~> 3.2" | |
| gem "tzinfo" | |
| # Let's use thin |
| # Ruby has #source_location method that returns code location where a method was declared. | |
| # What Ruby lacks is alike functionality that could show where an object was created. | |
| # Below is a very rough solution that may help with tracing object allocations | |
| # by storing the first entry in the caller list during object initialization phase. | |
| # It doesn't work for built-in classes like Fixnum and for classes that don't invoke #initialize() | |
| # like the ones derived from ActiveRecord::Base, but can be potentially tailored to address | |
| # at least the latter case by overriding ActiveRecord::Base.new in addition to overriding #initialize() | |
| class BasicObject | |
| attr_reader :allocated_at |
Copyright © 2017 Fantasyland Institute of Learning. All rights reserved.
A function is a mapping from one set, called a domain, to another set, called the codomain. A function associates every element in the domain with exactly one element in the codomain. In Scala, both domain and codomain are types.
val square : Int => Int = x => x * x