Contents

# coding: utf-8

module Valuevaluevalue
  class Mass
    attr_accessor :value, :unit

    UNITS = [
      MassUnit.new('Atomic Mass Unit', 'amu', 1.6605402e-27),
      MassUnit.new('Carat', 'ct', 0.0002),
      MassUnit.new('Cental', 'cwt', 45.359237),
      MassUnit.new('Centigram', 'cg', 0.00001),
      MassUnit.new('Decagram', 'dkg', 0.01),
      MassUnit.new('Dram', 'dr', 0.001771845195312),
      MassUnit.new('Grain', 'gr', 0.00006479891),
      MassUnit.new('Gram', 'g', 0.001),
      MassUnit.new('Hundredweight', 'hwt', 50.80234544),
      MassUnit.new('Kilogram', 'kg', 1),
      MassUnit.new('Long Ton', 'lton', 1016.0469088),
      MassUnit.new('Microgram', 'mcg', 1E-9),
      MassUnit.new('Milligram', 'mg', 0.000001),
      MassUnit.new('Ounce', 'oz', 0.028349523125),
      MassUnit.new('Pennyweight', 'dwt', 0.00155517384),
      MassUnit.new('Pound', 'lbs', 0.45359237),
      MassUnit.new('Quarter', 'qt', 12.70058636),
      MassUnit.new('Short Ton', 'ton', 907.18474),
      MassUnit.new('Stone', 'st', 6.35029318),
      MassUnit.new('Tonne', 't', 1000),
      MassUnit.new('Troy Ounce', 'troz', 0.0311034768)
    ].freeze

    def initialize(value, unit)
      unit_exists?(unit)
      @value = value
      @unit  = unit
    end

    def convert_to(unit)
      unit_exists?(unit)
      convert_to_kg / find_unit(unit).mass_in_kg
    end

    private

    def unit_exists?(unit)
      UNITS.include?(unit) ||
        UNITS.map(&:name).include?(unit.to_s) ||
        UNITS.map(&:abbreviation).include?(unit.to_s)
    end

    def find_unit(unit)
      raise 'Unit does not exist' unless unit_exists?(unit)
      unit = unit.to_s
      UNITS.select { |u| u.name == unit || u.abbreviation == unit }.first
    end

    def convert_to_kg
      value * unit.mass_in_kg
    end
  end
end

Version data entries

2 entries across 2 versions & 1 rubygems

Version	Path
valuevaluevalue-0.1.1	lib/valuevaluevalue/mass.rb
valuevaluevalue-0.1.0	lib/valuevaluevalue/mass.rb