Class: DiceBag::MinMaxCalc

Inherits:
Object
  • Object
show all
Defined in:
lib/dicebag/min_max_calc.rb

Overview

This is service class to calculate the Maximum/Minimum for the given Roll.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(roll, method) ⇒ MinMaxCalc

Returns a new instance of MinMaxCalc.



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# File 'lib/dicebag/min_max_calc.rb', line 25

def initialize(roll, method)
  @roll     = roll
  @method   = method
  @opposite = opposite_method
  @total    = 0
end

Instance Attribute Details

#method ⇒ Object (readonly)

Returns the value of attribute method.



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# File 'lib/dicebag/min_max_calc.rb', line 6

def method
  @method
end

#opposite ⇒ Object (readonly)

Returns the value of attribute opposite.



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# File 'lib/dicebag/min_max_calc.rb', line 7

def opposite
  @opposite
end

#roll ⇒ Object (readonly)

Returns the value of attribute roll.



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# File 'lib/dicebag/min_max_calc.rb', line 5

def roll
  @roll
end

Class Method Details

.average(roll) ⇒ Object 



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# File 'lib/dicebag/min_max_calc.rb', line 9

def self.average(roll)
  (maximum(roll) + minimum(roll)) / 2.0
end

.call(roll, method) ⇒ Object 



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# File 'lib/dicebag/min_max_calc.rb', line 21

def self.call(roll, method)
  new(roll, method).perform
end

.maximum(roll) ⇒ Object 



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# File 'lib/dicebag/min_max_calc.rb', line 13

def self.maximum(roll)
  call roll, :maximum
end

.minimum(roll) ⇒ Object 



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# File 'lib/dicebag/min_max_calc.rb', line 17

def self.minimum(roll)
  call roll, :minimum
end

Instance Method Details

#calculate(oper, part) ⇒ Object

Update the total based on the oper. For ‘additive’ operations, we use the method, but if it’s ‘subtractive’ then it uses the opposite method.



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# File 'lib/dicebag/min_max_calc.rb', line 45

def calculate(oper, part)
  case oper
  when :start then @total  = part.send(method)
  when :add   then @total += part.send(method)
  when :sub   then @total -= part.send(opposite)
  when :mul   then @total *= part.send(method)
  when :div   then @total /= part.send(opposite)
  end
end

#opposite_method ⇒ Object 



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# File 'lib/dicebag/min_max_calc.rb', line 55

def opposite_method
  method == :maximum ? :minimum : :maximum
end

#perform ⇒ Object 



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# File 'lib/dicebag/min_max_calc.rb', line 32

def perform
  roll.tree.each do |op, part|
    next unless part.is_a?(RollPart) || part.is_a?(StaticPart)

    calculate op, part
  end

  @total
end