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Class: Rake::LinkedList

Relationships & Source Files
Namespace Children
Classes:
EmptyLinkedList
Extension / Inclusion / Inheritance Descendants
Subclasses:
InvocationChain, Rake::Scope, InvocationChain::EmptyInvocationChain, EmptyLinkedList
Super Chains via Extension / Inclusion / Inheritance
Instance Chain:
self, Enumerable
Inherits: Object
Defined in: lib/rake/linked_list.rb

Overview

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

Constant Summary

Class Method Summary

Instance Attribute Summary

  • #empty? ⇒ Boolean readonly

    Is the list empty? .make guards against a list being empty making any instantiated LinkedList object not empty by default You should consider overriding this method if you implement your own .make method.

  • #head readonly
  • #tail readonly

Instance Method Summary

  • #==(other)

    Lists are structurally equivalent.

  • #conj(item)

    Polymorphically add a new element to the head of a list.

  • #each

    For each item in the list.

  • #inspect

    Same as #to_s, but with inspected items.

  • #to_s

    Convert to string: LL(item, item…).

Constructor Details

.new(head, tail = EMPTY) ⇒ LinkedList (protected)

[ GitHub ] 

  


# File 'lib/rake/linked_list.rb', line 83



def initialize(head, tail=EMPTY)
  @head = head
  @tail = tail
end


  







Class Method Details



  

    .cons(head, tail)  
  



  

    

Cons a new head onto the tail list.


  



  [ GitHub ]


  

  


# File 'lib/rake/linked_list.rb', line 72



def self.cons(head, tail)
  new(head, tail)
end


  








  

    .empty  
  



  

    

The standard empty list class for the given LinkedList class.


  



  [ GitHub ]


  

  


# File 'lib/rake/linked_list.rb', line 77



def self.empty
  self::EMPTY
end


  








  

    .make(*args)  
  



  

    

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


  



  [ GitHub ]


  

  


# File 'lib/rake/linked_list.rb', line 58



def self.make(*args)
  # return an EmptyLinkedList if there are no arguments
  return empty if !args || args.empty?

  # build a LinkedList by starting at the tail and iterating
  # through each argument
  # inject takes an EmptyLinkedList to start
  args.reverse.inject(empty) do |list, item|
    list = cons(item, list)
    list # return the newly created list for each item in the block
  end
end


  







Instance Attribute Details



  

    #empty?  ⇒ Boolean  (readonly)
  



  

    

Is the list empty? .make guards against a list being empty making any instantiated LinkedList object not empty by default You should consider overriding this method if you implement your own .make method


  





  


  [ GitHub ]


  

  


# File 'lib/rake/linked_list.rb', line 19



def empty?
  false
end


  








  

    #head   (readonly)
  

  [ GitHub ]


  

  


# File 'lib/rake/linked_list.rb', line 7



attr_reader :head, :tail


  








  

    #tail   (readonly)
  

  [ GitHub ]


  

  


# File 'lib/rake/linked_list.rb', line 7



attr_reader :head, :tail


  







Instance Method Details



  

    #==(other)  
  



  

    

Lists are structurally equivalent.


  



  [ GitHub ]


  

  


# File 'lib/rake/linked_list.rb', line 24



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)  
  



  

    

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.


  



  [ GitHub ]


  

  


# File 'lib/rake/linked_list.rb', line 11



def conj(item)
  self.class.cons(item, self)
end


  








  

    #each  
  



  

    

For each item in the list.


  



  [ GitHub ]


  

  


# File 'lib/rake/linked_list.rb', line 47



def each
  current = self
  while !current.empty?
    yield(current.head)
    current = current.tail
  end
  self
end


  








  

    #inspect  
  



  

    

Same as #to_s, but with inspected items.


  



  [ GitHub ]


  

  


# File 'lib/rake/linked_list.rb', line 41



def inspect
  items = map(&:inspect).join(", ")
  "LL(#{items})"
end


  








  

    #to_s  
  



  

    

Convert to string: LL(item, item…)


  



  [ GitHub ]


  

  


# File 'lib/rake/linked_list.rb', line 35



def to_s
  items = map(&:to_s).join(", ")
  "LL(#{items})"
end