Class: Integer

Inherits:

Object

• Object
• Integer

Defined in:

lib/setfu.rb,
lib/setfu.rb

Overview

for older rubbies … slow but works … >2.1.0 supports this and is much faster no need to improve as 1.9x is no longer supported

Instance Method Summary

• #bit_length ⇒ Object
• #lsb_bit_position ⇒ Object
• #msb_bit_position ⇒ Object

Instance Method Details

#bit_length ⇒ Object

# File 'lib/setfu.rb', line 1050

def bit_length
  pos = 0
  n = self
  loop do
    break if n == 0
    break if n == -1
    n >>= 1
    pos += 1
  end
  return pos
end

#lsb_bit_position ⇒ Object

# File 'lib/setfu.rb', line 1065

def lsb_bit_position
  return nil if zero?
  pos = 0
  n = self
  while (n & 0xffffffffffffffff) == 0
    n >>= 64
    pos += 64
  end
  while (n & 0xff) == 0
    n >>= 8
    pos += 8
  end
  mask = 1
  loop do
    break if mask == (n & mask)
    mask <<= 1
    pos += 1
  end
  return pos
end

#msb_bit_position ⇒ Object

# File 'lib/setfu.rb', line 1085

def msb_bit_position
  t = bit_length
  return t.zero? ? nil : t-1
end