Class: Quantified::Attribute

Inherits:
Object
  • Object
show all
Includes:
Comparable
Defined in:
lib/vendor/quantified/lib/quantified/attribute.rb

Direct Known Subclasses

Length, Mass

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(amount, unit) ⇒ Attribute

Returns a new instance of Attribute.

Raises:

  • (ArgumentError) 


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# File 'lib/vendor/quantified/lib/quantified/attribute.rb', line 7

def initialize(amount, unit)
  raise ArgumentError, "amount must be a Numeric" unless amount.is_a?(Numeric)
  @amount, @unit = amount, unit.to_sym
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(meth, *args) ⇒ Object 



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# File 'lib/vendor/quantified/lib/quantified/attribute.rb', line 42

def method_missing(meth, *args)
  if args.size == 1 && self.class == (other = args.first).class
    other_amount_in_self_units = self.class.convert(other.amount, other.unit, self.unit)
    self.class.new(amount.send(meth, other_amount_in_self_units), self.unit)
  else
    amount.send(meth, *args)
  end
end

Instance Attribute Details

#amount ⇒ Object (readonly)

Returns the value of attribute amount.



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# File 'lib/vendor/quantified/lib/quantified/attribute.rb', line 5

def amount
  @amount
end

#unit ⇒ Object (readonly)

Returns the value of attribute unit.



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# File 'lib/vendor/quantified/lib/quantified/attribute.rb', line 5

def unit
  @unit
end

Class Method Details

.add_numeric_methods? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/vendor/quantified/lib/quantified/attribute.rb', line 95

def self.add_numeric_methods?
  self.add_numeric_methods
end

.conversion_rate(from, to) ⇒ Object 



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# File 'lib/vendor/quantified/lib/quantified/attribute.rb', line 51

def self.conversion_rate(from, to)
  return nil unless self.conversions[from] and self.conversions[to]
  return self.conversions[from][to] ||=
  (1.0 / self.conversions[to][from] if self.conversions[to][from]) || begin
    shared_conversions = self.conversions[from].keys & self.conversions[to].keys
    if shared_conversions.any?
      primitive = shared_conversions.first
      self.conversions[from][primitive] * (1.0 / self.conversions[to][primitive])
    else
      self.conversions[from].each do |conversion_unit, multiple|
        if self.conversions[to].include?(conversion_unit)
          return multiple * conversion_rate(conversion) * (1.0 / self.conversions[to][conversion_unit])
        end
      end
      from_primitive = (self.conversions[from].keys & self.primitives).first
      to_primitive = (self.conversions[to].keys & self.primitives).first
      if from_primitive_to_primitive_multiple = conversion_rate(from_primitive, to_primitive)
        return self.conversions[from][from_primitive] * from_primitive_to_primitive_multiple * (1.0 / self.conversions[to][to_primitive])
      end
      raise StandardError, "No conversion path from #{from} to #{to}"
    end
  end
end

.non_primitives ⇒ Object 



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# File 'lib/vendor/quantified/lib/quantified/attribute.rb', line 87

def self.non_primitives
  self.conversions.keys
end

.numeric_methods(*args) ⇒ Object 



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# File 'lib/vendor/quantified/lib/quantified/attribute.rb', line 99

def self.numeric_methods(*args)
  args.each do |arg|
    add_numeric_method_for(arg.to_sym)
  end
end

.primitives ⇒ Object 



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# File 'lib/vendor/quantified/lib/quantified/attribute.rb', line 83

def self.primitives
  read_inheritable_attribute(:primitives).dup
end

.systems ⇒ Object 



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# File 'lib/vendor/quantified/lib/quantified/attribute.rb', line 91

def self.systems
  self.systems_to_units.keys
end

.units(system = nil) ⇒ Object 



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# File 'lib/vendor/quantified/lib/quantified/attribute.rb', line 75

def self.units(system=nil)
  if system
    self.systems_to_units[system.to_sym].dup
  else
    read_inheritable_attribute(:primitives) | self.conversions.keys
  end
end

Instance Method Details

#<=>(other) ⇒ Object 



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# File 'lib/vendor/quantified/lib/quantified/attribute.rb', line 30

def <=>(other)
  if self.class == other.class
    self.class.convert(self.amount, self.unit, other.unit) <=> other.amount
  else
    self.amount <=> other
  end
end

#==(other) ⇒ Object 



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# File 'lib/vendor/quantified/lib/quantified/attribute.rb', line 20

def ==(other)
  (BigDecimal.new(self.amount.to_s) == BigDecimal.new(other.amount.to_s) && self.unit == other.unit) || BigDecimal.new(self.class.convert(self.amount, self.unit, other.unit).to_s) == BigDecimal.new(other.amount.to_s)
rescue NoMethodError
  self.amount == other
end

#eql?(other) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/vendor/quantified/lib/quantified/attribute.rb', line 26

def eql?(other)
  self.class == other.class && BigDecimal.new(self.amount.to_s) == BigDecimal.new(other.amount.to_s) && self.unit == other.unit
end

#inspect ⇒ Object 



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# File 'lib/vendor/quantified/lib/quantified/attribute.rb', line 16

def inspect
  "#<#{self.class.name}: #{amount} #{unit}>"
end

#system ⇒ Object 



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# File 'lib/vendor/quantified/lib/quantified/attribute.rb', line 38

def system
  self.class.units_to_systems[unit]
end

#to_s ⇒ Object 



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# File 'lib/vendor/quantified/lib/quantified/attribute.rb', line 12

def to_s
  "#{amount} #{unit}"
end