Class: Random

Inherits:
Object show all
Extended by:
Formatter
Includes:
Formatter
Defined in:
opal/opal/corelib/random/formatter.rb,
opal/opal/corelib/random.rb,
opal/opal/corelib/random/seedrandom.js.rb,
opal/opal/corelib/random/math_random.js.rb,
opal/opal/corelib/random/mersenne_twister.rb

Overview

backtick_javascript: true

Constant Summary collapse

MATH_RANDOM_GENERATOR = 
`{
  new_seed: function() { return 0; },
  reseed: function(seed) { return {}; },
  rand: function($rng) { return Math.random(); }
}`

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(seed = ::Random.new_seed) ⇒ Random

Returns a new instance of Random.



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# File 'opal/opal/corelib/random.rb', line 19

def initialize(seed = ::Random.new_seed)
  seed = ::Opal.coerce_to!(seed, ::Integer, :to_int)
  @state = seed
  reseed(seed)
end

Instance Attribute Details

#seed ⇒ Object (readonly)

Returns the value of attribute seed.



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# File 'opal/opal/corelib/random.rb', line 7

def seed
  @seed
end

#state ⇒ Object (readonly)

Returns the value of attribute state.



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# File 'opal/opal/corelib/random.rb', line 7

def state
  @state
end

Class Method Details

._verify_count(count) ⇒ Object 



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# File 'opal/opal/corelib/random.rb', line 9

def self._verify_count(count)
  %x{
    if (!$truthy(count)) count = 16;
    if (typeof count !== "number") count = #{`count`.to_int};
    if (count < 0) #{::Kernel.raise ::ArgumentError, 'negative string size (or size too big)'};
    count = Math.floor(count);
    return count;
  }
end

.bytes(length) ⇒ Object 



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# File 'opal/opal/corelib/random.rb', line 62

def self.bytes(length)
  self::DEFAULT.bytes(length)
end

.generator=(generator) ⇒ Object 



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# File 'opal/opal/corelib/random.rb', line 84

def self.generator=(generator)
  `Opal.$$rand = #{generator}`

  if const_defined? :DEFAULT
    self::DEFAULT.reseed
  else
    const_set :DEFAULT, new(new_seed)
  end
end

.new_seed ⇒ Object 



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# File 'opal/opal/corelib/random.rb', line 30

def self.new_seed
  `Opal.$$rand.new_seed()`
end

.rand(limit = undefined) ⇒ Object 



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# File 'opal/opal/corelib/random.rb', line 34

def self.rand(limit = undefined)
  self::DEFAULT.rand(limit)
end

.random_float ⇒ Object 



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# File 'opal/opal/corelib/random.rb', line 80

def self.random_float
  self::DEFAULT.random_float
end

.srand(n = ::Random.new_seed) ⇒ Object 



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# File 'opal/opal/corelib/random.rb', line 38

def self.srand(n = ::Random.new_seed)
  n = ::Opal.coerce_to!(n, ::Integer, :to_int)

  previous_seed = self::DEFAULT.seed
  self::DEFAULT.reseed(n)
  previous_seed
end

.urandom(size) ⇒ Object 



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# File 'opal/opal/corelib/random.rb', line 46

def self.urandom(size)
  ::SecureRandom.bytes(size)
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'opal/opal/corelib/random.rb', line 50

def ==(other)
  return false unless ::Random === other

  seed == other.seed && state == other.state
end

#bytes(length) ⇒ Object 



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# File 'opal/opal/corelib/random.rb', line 56

def bytes(length)
  length = ::Random._verify_count(length)

  ::Array.new(length) { rand(255).chr }.join.encode('ASCII-8BIT')
end

#rand(limit = undefined) ⇒ Object 



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# File 'opal/opal/corelib/random.rb', line 66

def rand(limit = undefined)
  random_number(limit)
end

#random_float ⇒ Object

Not part of the Ruby interface (use #random_number for portability), but used by Random::Formatter as a shortcut, as for Random interface the float RNG is primary.



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# File 'opal/opal/corelib/random.rb', line 73

def random_float
  %x{
    self.state++;
    return Opal.$$rand.rand(self.$rng);
  }
end

#reseed(seed) ⇒ Object 



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# File 'opal/opal/corelib/random.rb', line 25

def reseed(seed)
  @seed = seed
  `self.$rng = Opal.$$rand.reseed(seed)`
end