Class: Numerals::Digits

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Includes:
ModalSupport::BracketConstructor, ModalSupport::StateEquivalent
Defined in:
lib/numerals/digits.rb

Overview

Sequence of digit values, with an Array-compatible interface. Having this encapsulated here allows changing the implementation e.g. to an Integer or packed in a String, …

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ Digits

Returns a new instance of Digits



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# File 'lib/numerals/digits.rb', line 9

def initialize(*args)
  if Hash === args.last
    options = args.pop
  else
    options = {}
  end
  @radix = options[:base] || options[:radix] || 10
  if args.size == 1 && Array === args.first
    @digits_array = args.first
  else
    @digits_array = args
  end
  if options[:value]
    self.value = options[:value]
  end
end

Instance Attribute Details

#digits_arrayObject (readonly)

Returns the value of attribute digits_array



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# File 'lib/numerals/digits.rb', line 28

def digits_array
  @digits_array
end

#radixObject (readonly)

Returns the value of attribute radix



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# File 'lib/numerals/digits.rb', line 28

def radix
  @radix
end

Instance Method Details

#dupObject

Deep copy



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# File 'lib/numerals/digits.rb', line 75

def dup
  Digits[@digits_array.dup, base: @radix]
end

#inspectObject



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# File 'lib/numerals/digits.rb', line 89

def inspect
  to_s
end

#to_sObject



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# File 'lib/numerals/digits.rb', line 79

def to_s
  args = ""
  if @digits_array.size > 0
    args << @digits_array.to_s.unwrap('[]')
    args << ', '
  end
  args << "base: #{radix}"
  "Digits[#{args}]"
end

#truncate!(n) ⇒ Object



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# File 'lib/numerals/digits.rb', line 93

def truncate!(n)
  @digits_array.slice! n..-1
end

#valid?Boolean

Returns:

  • (Boolean)


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# File 'lib/numerals/digits.rb', line 97

def valid?
  @digits_array.none? { |x| !x.kind_of?(Integer) || x < 0 || x >= @radix }
end

#valueObject

Integral coefficient



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# File 'lib/numerals/digits.rb', line 45

def value
  if @radix == 10
    @digits_array.join.to_i
  else
    @digits_array.inject(0){|x,y| x*@radix + y}
  end
end

#value=(v) ⇒ Object



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# File 'lib/numerals/digits.rb', line 53

def value=(v)
  raise "Invalid digits value" if v < 0
  if @radix < 37
    replace v.to_s(@radix).each_char.map{|c| c.to_i(@radix)}
  else
    if v == 0
      replace [0]
    else
      while v > 0
        v, r = v.divmod(@radix)
        unshift r
      end
    end
  end
end

#zero?Boolean

Returns:

  • (Boolean)


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# File 'lib/numerals/digits.rb', line 69

def zero?
  # value == 0
  !@digits_array || @digits_array.empty? || @digits_array.all?{|d| d==0 }
end