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Class: Prime::Generator23

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, PseudoPrimeGenerator
Instance Chain:
self, PseudoPrimeGenerator, Enumerable
Inherits: Prime::PseudoPrimeGenerator
Defined in: lib/prime.rb

Overview

Generates all integers which are greater than 2 and are not divisible by either 2 or 3.

This is a pseudo-prime generator, suitable on checking primality of an integer by brute force method.

Class Method Summary

PseudoPrimeGenerator - Inherited

.new

Instance Attribute Summary

PseudoPrimeGenerator - Inherited

#upper_bound, #upper_bound=

Instance Method Summary

PseudoPrimeGenerator - Inherited

#each

Iterates the given block for each prime number.
#next

alias of #succ.
#rewind

Rewinds the internal position for enumeration.
#size,
#succ

returns the next pseudo-prime number, and move the internal position forward.
#with_index

see Enumerator#with_index.
#with_object

see Enumerator#with_object.

Constructor Details

.new ⇒ Generator23

[ GitHub ] 

  


# File 'lib/prime.rb', line 450



def initialize
  @prime = 1
  @step = nil
  super
end


  







Instance Method Details



  

    #next  
  



  

    

Alias for #succ.


  



  [ GitHub ]


  

  


# File 'lib/prime.rb', line 469



alias next succ


  








  

    #rewind  
  

  [ GitHub ]


  

  


# File 'lib/prime.rb', line 470



def rewind
  initialize
end


  








  

    #succ  
    Also known as: #next
  

  [ GitHub ]


  

  


# File 'lib/prime.rb', line 456



def succ
  if (@step)
    @prime += @step
    @step = 6 - @step
  else
    case @prime
    when 1; @prime = 2
    when 2; @prime = 3
    when 3; @prime = 5; @step = 2
    end
  end
  @prime
end