class Quantified::Attribute

Constants

PLURAL_EXCEPTIONS

Attributes

add_numeric_methods[W]
current_system[RW]
amount[R]
unit[R]

Public Class Methods

add_numeric_methods?() click to toggle source
# File lib/quantified/attribute.rb, line 95
def self.add_numeric_methods?
  add_numeric_methods
end
coder(unit) click to toggle source
# File lib/quantified/attribute.rb, line 105
def self.coder(unit)
  Coder.new(self, unit)
end
conversion_rate(from, to) click to toggle source
# File lib/quantified/attribute.rb, line 55
def self.conversion_rate(from, to)
  return nil unless conversions[from] and conversions[to]
  conversions[from][to] ||=
  (1.0 / conversions[to][from] if conversions[to][from]) || begin
    shared_conversions = conversions[from].keys & conversions[to].keys
    if shared_conversions.any?
      primitive = shared_conversions.first
      conversions[from][primitive] * (1.0 / conversions[to][primitive])
    else
      conversions[from].each do |conversion_unit, multiple|
        if conversions[to].include?(conversion_unit)
          return multiple * conversion_rate(conversion) * (1.0 / conversions[to][conversion_unit])
        end
      end
      from_primitive = (conversions[from].keys & primitives).first
      to_primitive = (conversions[to].keys & primitives).first
      if from_primitive_to_primitive_multiple = conversion_rate(from_primitive, to_primitive)
        return conversions[from][from_primitive] * from_primitive_to_primitive_multiple * (1.0 / conversions[to][to_primitive])
      end
      raise StandardError, "No conversion path from #{from} to #{to}"
    end
  end
end
new(amount, unit) click to toggle source
# File 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
non_primitives() click to toggle source
# File lib/quantified/attribute.rb, line 87
def self.non_primitives
  conversions.keys
end
numeric_methods(*args) click to toggle source
# File lib/quantified/attribute.rb, line 99
def self.numeric_methods(*args)
  args.each do |arg|
    add_numeric_method_for(arg.to_sym)
  end
end
systems() click to toggle source
# File lib/quantified/attribute.rb, line 91
def self.systems
  systems_to_units.keys
end
units(system = nil) click to toggle source
# File lib/quantified/attribute.rb, line 79
def self.units(system = nil)
  if system
    systems_to_units[system.to_sym].dup
  else
    primitives | conversions.keys
  end
end

Protected Class Methods

add_coder_method_for(sym, options = {}) click to toggle source
# File lib/quantified/attribute.rb, line 205
def self.add_coder_method_for(sym, options = {})
  (class << self; self; end).instance_eval do
    define_method(sym) do
      Coder.new(self, sym)
    end
  end
end
add_conversion(multiple_unit, other_unit, multiple) click to toggle source
# File lib/quantified/attribute.rb, line 171
def self.add_conversion(multiple_unit, other_unit, multiple)
  conversions[multiple_unit] ||= {}
  conversions[multiple_unit][other_unit] = multiple
  conversions[other_unit] ||= {}
  conversions[other_unit][multiple_unit] = (1.0 / multiple)
end
add_conversion_method_for(sym, options = {}) click to toggle source
# File lib/quantified/attribute.rb, line 194
def self.add_conversion_method_for(sym, options = {})
  unit_name = sym.to_s
  class_eval do
    define_method("to_#{unit_name}") do
      return self if unit_name == unit.to_s
      self.class.new(self.class.convert(amount, unit, unit_name), unit_name)
    end
    alias_method("in_#{unit_name}", "to_#{unit_name}")
  end
end
add_methods_for(sym, options = {}) click to toggle source
# File lib/quantified/attribute.rb, line 183
def self.add_methods_for(sym, options = {})
  add_conversion_method_for(sym, options)
  add_coder_method_for(sym, options)
  add_numeric_method = if options.has_key?(:add_numeric_methods)
    options[:add_numeric_methods]
  else
    add_numeric_methods
  end
  add_numeric_method_for(sym.to_s, options) if add_numeric_method
end
add_numeric_method_for(unit_name, options = {}) click to toggle source
# File lib/quantified/attribute.rb, line 213
def self.add_numeric_method_for(unit_name, options = {})
  unit_name = unit_name.to_sym
  raise ArgumentError, "#{unit_name.inspect} is not a unit in #{name}" unless units.include?(unit_name)
  klass = self
  Numeric.class_eval do
    define_method(unit_name) do
      klass.new(self, unit_name.to_sym)
    end
  end
end
add_numeric_methods() click to toggle source
# File lib/quantified/attribute.rb, line 113
def add_numeric_methods;     @add_numeric_methods ||= false; end
add_to_system(unit_sym) click to toggle source
# File lib/quantified/attribute.rb, line 136
def self.add_to_system(unit_sym)
  if current_system
    units_to_systems[unit_sym] ||= begin
      sys_ary = systems_to_units[current_system] ||= []
      sys_ary << unit_sym
      current_system
    end
  end
end
conversions() click to toggle source
# File lib/quantified/attribute.rb, line 115
def conversions;             @conversions ||= {};            end
convert(amount, from, to) click to toggle source
# File lib/quantified/attribute.rb, line 178
def self.convert(amount, from, to)
  from, to = from.to_sym, to.to_sym
  amount * conversion_rate(from, to)
end
one(sym, options = {}) click to toggle source
# File lib/quantified/attribute.rb, line 146
def self.one(sym, options = {})
  unit_sym = pluralize_unit(sym, options[:plural]).to_sym
  add_to_system(unit_sym)
  register_unit(unit_sym, options[:is].unit, options[:is].amount)
  add_methods_for(unit_sym, options)
end
pluralize_unit(word, provided_plural = nil) click to toggle source
# File lib/quantified/attribute.rb, line 230
def self.pluralize_unit(word, provided_plural = nil)
  return provided_plural unless provided_plural.nil?
  PLURAL_EXCEPTIONS[word.to_s] || "#{word}s"
end
primitive(sym, options = {}) click to toggle source
# File lib/quantified/attribute.rb, line 129
def self.primitive(sym, options = {})
  unit_sym = pluralize_unit(sym, options[:plural]).to_sym
  primitives << unit_sym
  add_to_system(unit_sym)
  add_methods_for(unit_sym, options)
end
primitives() click to toggle source
# File lib/quantified/attribute.rb, line 112
def primitives;              @primitives ||= [];             end
register_unit(multiple_unit, other_unit, multiple) click to toggle source
# File lib/quantified/attribute.rb, line 153
def self.register_unit(multiple_unit, other_unit, multiple)
  multiple_unit, other_unit = multiple_unit.to_sym, other_unit.to_sym
  conversions[multiple_unit] ||= {}
  conversions[other_unit] ||= {}

  if primitives.include?(multiple_unit) || primitives.include?(other_unit)
    add_conversion(multiple_unit, other_unit, multiple)
  else
    [multiple_unit, other_unit].each do |this_unit|
      conversions[this_unit].each do |this_other_unit, this_multiple|
        if primitives.include?(this_other_unit)
          add_conversion(multiple_unit, this_other_unit, multiple * this_multiple)
        end
      end
    end
  end
end
system(system_name) { || ... } click to toggle source
# File lib/quantified/attribute.rb, line 122
def self.system(system_name, &block)
  old_system = current_system
  self.current_system = system_name.to_sym
  yield
  self.current_system = old_system
end
systems_to_units() click to toggle source
# File lib/quantified/attribute.rb, line 118
def systems_to_units;        @systems_to_units ||= {};       end
units_to_systems() click to toggle source
# File lib/quantified/attribute.rb, line 119
def units_to_systems;        @units_to_systems ||= {};       end

Public Instance Methods

<=>(other) click to toggle source
# File lib/quantified/attribute.rb, line 30
def <=>(other)
  if self.class == other.class
    self.class.convert(amount, unit, other.unit) <=> other.amount
  else
    amount <=> other
  end
end
==(other) click to toggle source
# File lib/quantified/attribute.rb, line 20
def ==(other)
  (BigDecimal.new(amount.to_s) == BigDecimal.new(other.amount.to_s) && unit == other.unit) || BigDecimal.new(self.class.convert(amount, unit, other.unit).to_s) == BigDecimal.new(other.amount.to_s)
rescue NoMethodError
  amount == other
end
coerce(other) click to toggle source
# File lib/quantified/attribute.rb, line 42
def coerce(other)
  [other, amount]
end
eql?(other) click to toggle source
# File lib/quantified/attribute.rb, line 26
def eql?(other)
  self.class == other.class && BigDecimal.new(amount.to_s) == BigDecimal.new(other.amount.to_s) && unit == other.unit
end
inspect() click to toggle source
# File lib/quantified/attribute.rb, line 16
def inspect
  "#<#{self.class.name}: #{amount} #{unit}>"
end
method_missing(meth, *args) click to toggle source
# File lib/quantified/attribute.rb, line 46
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, unit)
    self.class.new(amount.send(meth, other_amount_in_self_units), unit)
  else
    amount.send(meth, *args)
  end
end
system() click to toggle source
# File lib/quantified/attribute.rb, line 38
def system
  self.class.units_to_systems[unit]
end
to_s() click to toggle source
# File lib/quantified/attribute.rb, line 12
def to_s
  "#{amount} #{unit}"
end