Class: Fixed

Inherits:
Numeric
  • Object
show all
Defined in:
lib/is/fixed.rb

Constant Summary collapse

VERSION = 
'0.2.0'

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(number = 0, shift = nil) ⇒ Fixed

Returns a new instance of Fixed.

Parameters:

  • number (Numeric) (defaults to: 0)
  • shift (Integer) (defaults to: nil) 


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# File 'lib/is/fixed.rb', line 65

def initialize number = 0, shift = nil
  if ! precision
    raise 'Undefined precision.'
  end
  case number
  when Fixed
    np = number.precision + (shift || 0)
    if np = precision
      @number = number.number
    elsif np < precision
      @number = number.number * 10 ** (precision - np)
    else
      nn = number.number.divmod(10 ** (np - precision))
      @number = nn[0] + (nn[1] < 5 && 0 || 1)
    end
  when Integer
    np = (shift || 0)
    if np == precision
      @number = number
    elsif np < precision
      @number = number * 10 ** (precision - np)
    else
      nn = number.divmod(10 ** (np - precision))
      @number = nn[0] + (nn[1] < 5 && 0 || 1)
    end
  else
    np = (shift || 0)
    @number = (Float(number) * Float(10) ** (precision - np)).round
  end
end

Class Attribute Details

.precision ⇒ Integer

Returns:

  • (Integer) 


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# File 'lib/is/fixed.rb', line 10

def precision
  @precision
end

Instance Attribute Details

#number ⇒ Integer (readonly, protected)

Returns:

  • (Integer) 


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# File 'lib/is/fixed.rb', line 57

def number
  @number
end

#precision ⇒ Integer (readonly, protected)

Returns:

  • (Integer) 


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# File 'lib/is/fixed.rb', line 54

def precision
  @precision
end

Class Method Details

.[](value) ⇒ Fixed

Parameters:

  • value (Numeric)

Returns:



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# File 'lib/is/fixed.rb', line 42

def [] value
  self.new value
end

.number(value, precision) ⇒ Fixed

Parameters:

  • value (Numeric)
  • precision (Integer)

Returns:



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# File 'lib/is/fixed.rb', line 36

def number value, precision
  subclass(precision).new(value)
end

.subclass(precision) ⇒ Class

Parameters:

  • precision (Integer)

Returns:

  • (Class) 


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# File 'lib/is/fixed.rb', line 24

def subclass precision
  @@classes ||= []
  if ! @@classes[precision]
    @@classes[precision] = Class.new(Fixed)
    @@classes[precision].precision = precision
  end
  @@classes[precision]
end

.to_s ⇒ String

Returns:

  • (String) 


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# File 'lib/is/fixed.rb', line 47

def to_s
  name || "Fixed(#{@precision})"
end

Instance Method Details

#*(other) ⇒ Fixed

Parameters:

  • other (Numeric)

Returns:



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# File 'lib/is/fixed.rb', line 121

def * other
  case other
  when Fixed
    self.class.new @number * other.number, precision + other.precision
  when Integer
    self.class.new @number * other, precision
  else
    self.class.new (Float(other) * @number).round, precision
  end
end

#**(other) ⇒ Fixed

Parameters:

  • other (Numeric)

Returns:



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# File 'lib/is/fixed.rb', line 151

def ** other
  case other
  when Integer
    n = self.class.new 1
    if other > 0
      other.times { n = n * self }
    elsif other < 0
      other.times { n = n / self }
    end
    n
  when Fixed
    if other.integer?
      self ** other.to_i
    else
      self ** other.to_f
    end
  else
    self.class.new self.to_f ** Float(other)
  end
end

#+(other) ⇒ Fixed

Parameters:

  • other (Numeric)

Returns:



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# File 'lib/is/fixed.rb', line 108

def + other
  other = self.class.new other
  self.class.new @number + other.number, precision
end

#+@ ⇒ Fixed

Returns:



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# File 'lib/is/fixed.rb', line 97

def +@
  self
end

#-(other) ⇒ Fixed

Parameters:

  • other (Numeric)

Returns:



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# File 'lib/is/fixed.rb', line 115

def - other
  self + (-other)
end

#-@ ⇒ Fixed

Returns:



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# File 'lib/is/fixed.rb', line 102

def -@
  self.class.new -@number, precision
end

#/(other) ⇒ Fixed

Parameters:

  • other (Numeric)

Returns:



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# File 'lib/is/fixed.rb', line 134

def / other
  # /
  case other
  when Fixed
    n = @number * 10 ** other.precision
    nn = n.divmod other.number
    self.class.new nn[0] + (nn[1] < 5 && 0 || 1), precision
  when Integer
    nn = @number.divmod other
    self.class.new nn[0] + (nn[1] < 5 && 0 || 1) / other.number, precision
  else
    self.class.new Float(@number) / Float(other), precision
  end
end

#<=>(other) ⇒ Object 



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# File 'lib/is/fixed.rb', line 196

def <=> other
  if precision >= other.precision
    @number <=> self.class.new(other).number
  else
    other.class.new(self).number <=> other.number
  end
end

#abs ⇒ Object 



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# File 'lib/is/fixed.rb', line 204

def abs
  self.class.new(@number.abs, precision)
end

#abs2 ⇒ Object 



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# File 'lib/is/fixed.rb', line 208

def abs2
  self * self
end

#coerce(other) ⇒ Object 



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# File 'lib/is/fixed.rb', line 212

def coerce other
  if Integer === other
    [self.class.new(other), self]
  else
    super other
  end
end

#integer? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/is/fixed.rb', line 172

def integer?
  @number.divmod(10 ** precision)[1] == 0
end

#to_f ⇒ Float

Returns:

  • (Float) 


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# File 'lib/is/fixed.rb', line 182

def to_f
  Float(@number) / Float(10 ** precision)
end

#to_i ⇒ Integer

Returns:

  • (Integer) 


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# File 'lib/is/fixed.rb', line 177

def to_i
  @number.divmod(10 ** precision)[0]
end

#to_s ⇒ String

Returns:

  • (String) 


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# File 'lib/is/fixed.rb', line 187

def to_s
  s = @number.to_s
  l = s.length
  if l <= precision
    s = '0' * (precision - l + 1) + s
  end
  "#{s[0...-precision]}.#{s[-precision..-1]}"
end