Class: Medidas::Measure

Inherits:
Object
  • Object
show all
Includes:
Comparable
Defined in:
lib/medidas/measure.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(amount:, unit:) ⇒ Measure

Returns a new instance of Measure.



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# File 'lib/medidas/measure.rb', line 16

def initialize(amount:, unit:)
  @amount = BigDecimal(amount.to_s)
  @unit   = unit
end

Instance Attribute Details

#amount ⇒ Object (readonly)

Returns the value of attribute amount.



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# File 'lib/medidas/measure.rb', line 7

def amount
  @amount
end

#unit ⇒ Object (readonly)

Returns the value of attribute unit.



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# File 'lib/medidas/measure.rb', line 8

def unit
  @unit
end

Class Method Details

.for(amount:, unit:) ⇒ Object 



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# File 'lib/medidas/measure.rb', line 12

def self.for(amount:, unit:)
  @registered_measures[[amount, unit]] ||= new(amount: amount, unit: unit)
end

Instance Method Details

#*(a_number) ⇒ Object

Raises:

  • (CANT_APPLY_OPERATION) 


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# File 'lib/medidas/measure.rb', line 33

def *(a_number)
  raise CANT_APPLY_OPERATION unless a_number.is_a?(Numeric)

  (a_number * amount) * unit
end

#+(other_measure) ⇒ Object 



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# File 'lib/medidas/measure.rb', line 21

def +(other_measure)
  assert_same_unit!(other_measure)

  unit * (amount + other_measure.amount)
end

#-(other_measure) ⇒ Object 



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# File 'lib/medidas/measure.rb', line 27

def -(other_measure)
  assert_same_unit!(other_measure)

  unit * (amount - other_measure.amount)
end

#-@ ⇒ Object 



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# File 'lib/medidas/measure.rb', line 49

def -@
  unit * (amount * -1)
end

#/(a_divisor) ⇒ Object

Raises:

  • (CANT_APPLY_OPERATION) 


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# File 'lib/medidas/measure.rb', line 39

def /(a_divisor)
  raise CANT_APPLY_OPERATION if a_divisor.is_a?(Measure) && !a_divisor.unit?(unit)

  if a_divisor.is_a?(Numeric)
    (amount / a_divisor) * unit
  else
    amount / a_divisor.amount
  end
end

#<=>(other_measure) ⇒ Object

Raises:

  • (CANT_APPLY_OPERATION) 


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# File 'lib/medidas/measure.rb', line 69

def <=>(other_measure)
  raise CANT_APPLY_OPERATION unless other_measure.is_a?(Measure) && other_measure.base_unit?(unit.base_unit)

  to_base_unit.amount <=> other_measure.to_base_unit.amount
end

#base_unit ⇒ Object 



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# File 'lib/medidas/measure.rb', line 61

def base_unit
  unit.base_unit
end

#base_unit?(a_unit) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/medidas/measure.rb', line 57

def base_unit?(a_unit)
  unit.base_unit?(a_unit)
end

#convert_to(unit) ⇒ Object 



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# File 'lib/medidas/measure.rb', line 65

def convert_to(unit)
  (to_base_unit.amount / unit.factor) * unit
end

#inspect ⇒ Object 



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# File 'lib/medidas/measure.rb', line 79

def inspect
  "#{self.class}(#{text_for_amount} #{unit.to_s})"
end

#to_base_unit ⇒ Object 



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# File 'lib/medidas/measure.rb', line 53

def to_base_unit
  amount * unit.factor * unit.base_unit
end

#to_s ⇒ Object 



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# File 'lib/medidas/measure.rb', line 75

def to_s
  "#{text_for_amount} #{unit.name_for(amount)}"
end

#unit?(potential_unit) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/medidas/measure.rb', line 83

def unit?(potential_unit)
  unit == potential_unit
end