Class: GLW::Random

Inherits:
Object
  • Object
show all
Defined in:
lib/glw/random.rb

Constant Summary collapse

MASK64 = 
(1 << 64) - 1
MASK32 = 
(1 << 32) - 1
CONST = 
0x2545F4914F6CDD1D

Instance Method Summary collapse

Constructor Details

#initialize(seed) ⇒ Random 



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# File 'lib/glw/random.rb', line 7

def initialize(seed)
  @state = seed & MASK64
end

Instance Method Details

#float ⇒ Object 



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# File 'lib/glw/random.rb', line 25

def float
  integer.to_f / (1 << 32)
end

#integer ⇒ Object 



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# File 'lib/glw/random.rb', line 15

def integer
  x = state
  x = (x ^ (x >> 12)) & MASK64
  x = (x ^ (x << 25)) & MASK64
  x = (x ^ (x >> 27)) & MASK64
  self.state = x

  (((x * CONST) & MASK64) >> 32) & MASK32
end

#sample(collection) ⇒ Object 



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# File 'lib/glw/random.rb', line 11

def sample(collection)
  collection[integer % collection.length]
end