Module: ReversePolishCalculator::Inputs

Defined in:
lib/reverse-polish-calculator/inputs.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#swapped ⇒ Object

Returns the value of attribute swapped.



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# File 'lib/reverse-polish-calculator/inputs.rb', line 4

def swapped
  @swapped
end

Instance Method Details

#add_operand(input) ⇒ Object 



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# File 'lib/reverse-polish-calculator/inputs.rb', line 24

def add_operand(input)
  @operands << input
  @calculated = false
end

#calculate(aggregate = 0) ⇒ Object 



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# File 'lib/reverse-polish-calculator/inputs.rb', line 6

def calculate(aggregate = 0)
  @operands, @trash = [], []
  @aggregate = aggregate
  
  each do |input|        
    if input.operand?
      add_operand(input)
    elsif input.math_method?
      invoke_math_method(input)
    else          
      invoke_binary_operator(input)
    end
  end
  
  empty_trash
  calculation
end

#calculation ⇒ Object 



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# File 'lib/reverse-polish-calculator/inputs.rb', line 58

def calculation
  if @calculated
    if swapped
      @operands.first
    else
      @aggregate + @operands.last.to_f
    end
  else
    @aggregate
  end
end

#empty_trash ⇒ Object 



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# File 'lib/reverse-polish-calculator/inputs.rb', line 70

def empty_trash
  delete_if {|input| @trash.include?(input) }
end

#inspect ⇒ Object 



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# File 'lib/reverse-polish-calculator/inputs.rb', line 74

def inspect
  map(&:to_f).join(', ')
end

#invoke_binary_operator(input) ⇒ Object 



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# File 'lib/reverse-polish-calculator/inputs.rb', line 36

def invoke_binary_operator(input)
  operand_1 = @operands.pop
  operand_2 = @operands.pop
  
  unless operand_2
    self.swapped = true
    operand_2 = operand_1
    operand_1 = @aggregate
  else
    self.swapped = false
  end

  @operands.push(if @swapped
    input.invoke(operand_1, operand_2)
  else
    input.invoke(operand_2, operand_1)
  end)
  
  @trash << input << operand_1 << operand_2
  @calculated = true
end

#invoke_math_method(input) ⇒ Object 



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# File 'lib/reverse-polish-calculator/inputs.rb', line 29

def invoke_math_method(input)
  operand = @operands.pop || @aggregate
  @operands.push input.invoke(operand)
  @trash << input << operand
  @calculated = true
end