Spec for a sorted linked list

This is a spec for a sorted linked list.

It expects a base class called SortedList. It will expect a method head to the first node in the list, though this method can be private.

It expects each node to have a method next_node to the next node in the list.

Solution is in branch solved.

Purpose

To provide a fun but nontrivial problem to solve. To play with the idea of storing blocks for later use.

Examples

Sorted forwards:

list = SortedList.new do |left, right|
  left <=> right
end

list.add(3).add(1).add(2)
list.to_a # => [3, 2, 1]

Sorted backwards:

list = SortedList.new do |left, right|
  right <=> left
end

list.add('c').add('a').add('b')
list.to_a # => ["c", "b", "a"]

Usage:

• Install dependencies (rspec) with $ bundle
• Run specs with $ rake
• When developing, run specs until first failure with $ rake spec:dev