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Class: Integer

Relationships & Source Files
Inherits: Object
Defined in: lib/prime.rb

Class Method Summary

Instance Attribute Summary

Instance Method Summary

Class Method Details

.each_prime(ubound, &block)

Iterates the given block over all prime numbers.

See ::Prime#each for more details.

[ GitHub ]

  
# File 'lib/prime.rb', line 49

def Integer.each_prime(ubound, &block) # :yields: prime
  Prime.each(ubound, &block)
end

.from_prime_division(pd)

Re-composes a prime factorization and returns the product.

See Prime#int_from_prime_division for more details.

[ GitHub ]

  
# File 'lib/prime.rb', line 22

def Integer.from_prime_division(pd)
  Prime.int_from_prime_division(pd)
end

Instance Attribute Details

#prime?Boolean (readonly)

Returns true if self is a prime number, else returns false.

[ GitHub ]

  
# File 'lib/prime.rb', line 34

def prime?
  return self >= 2 if self <= 3
  return true if self == 5
  return false unless 30.gcd(self) == 1
  (7..Math.sqrt(self).to_i).step(30) do |p|
    return false if
      self%(p)    == 0 || self%(p+4)  == 0 || self%(p+6)  == 0 || self%(p+10) == 0 ||
      self%(p+12) == 0 || self%(p+16) == 0 || self%(p+22) == 0 || self%(p+24) == 0
  end
  true
end

Instance Method Details

#prime_division(generator = Prime::Generator23.new)

Returns the factorization of self.

See Prime#prime_division for more details.

[ GitHub ]

  
# File 'lib/prime.rb', line 29

def prime_division(generator = Prime::Generator23.new)
  Prime.prime_division(self, generator)
end