class Rake::LinkedList

Polylithic linked list structure used to implement several data structures in Rake.

Constants

EMPTY

Attributes

head[R]

tail[R]

Public Class Methods

cons(head, tail) click to toggle source

Cons a new head onto the tail list.

# File lib/rake/linked_list.rb, line 70
def self.cons(head, tail)
  new(head, tail)
end

empty() click to toggle source

The standard empty list class for the given LinkedList class.

# File lib/rake/linked_list.rb, line 75
def self.empty
  self::EMPTY
end

make(*args) click to toggle source

Make a list out of the given arguments. This method is polymorphic

# File lib/rake/linked_list.rb, line 61
def self.make(*args)
  result = empty
  args.reverse_each do |item|
    result = cons(item, result)
  end
  result
end

new(head, tail=EMPTY) click to toggle source

# File lib/rake/linked_list.rb, line 10
def initialize(head, tail=EMPTY)
  @head = head
  @tail = tail
end

Public Instance Methods

==(other) click to toggle source

Lists are structurally equivalent.

# File lib/rake/linked_list.rb, line 27
def ==(other)
  current = self
  while ! current.empty? && ! other.empty?
    return false if current.head != other.head
    current = current.tail
    other = other.tail
  end
  current.empty? && other.empty?
end

conj(item) click to toggle source

Polymorphically add a new element to the head of a list. The type of head node will be the same list type as the tail.

# File lib/rake/linked_list.rb, line 17
def conj(item)
  self.class.cons(item, self)
end

each() { |head| ... } click to toggle source

For each item in the list.

# File lib/rake/linked_list.rb, line 50
def each
  current = self
  while ! current.empty?
    yield(current.head)
    current = current.tail
  end
  self
end

empty?() click to toggle source

Is the list empty?

# File lib/rake/linked_list.rb, line 22
def empty?
  false
end

inspect() click to toggle source

Same as to_s, but with inspected items.

# File lib/rake/linked_list.rb, line 44
def inspect
  items = map { |item| item.inspect }.join(", ")
  "LL(#{items})"
end

to_s() click to toggle source

Convert to string: LL(item, item…)

# File lib/rake/linked_list.rb, line 38
def to_s
  items = map { |item| item.to_s }.join(", ")
  "LL(#{items})"
end