How ModularCounter method calls work with Inheritance

(nf)   : (not found), check higher base class in inheritance hierarchy
self/m : self parameter in method name (actually bound to m)

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m = Modular_Counter(2,10)

Call		m.reset()
FEOOP		Modular_Counter.reset(m)
(nf)Inheritance	Counter.reset(m)
Method Body		self/m._value = 0

m._value is now 0

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m = Modular_Counter(2,10)  # inc calls Counter.inc

Call		m.inc()
FEOOP		Modular_Counter.inc(m)
Method Body (if test)   self/m.value_of()
FEOOP			Modular_Counter.value_of(self/m)
(nf) Inheritance	Counter.value_of(self/m)
Method Body			return self/m._value (2)
Method Body (if)	compares (2) == self._modulus -1 (False, in if)
Body if (False part)	Counter.inc(self/m)
Method Body	 		self/m._value += 1

m._value is now 3

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m = Modular_Counter(9,10) # inc calls reset

Call		m.inc()
FEOOP		Modular_Counter.inc(m)
Method Body (if)        self/m.value_of()
FEOOP			Modular_Counter.value_of(self/m)
(nf) Inheritance	Counter.value_of(self/m)
Method Body			return self/m._value (9)
Method Body (if)        compares (9) == self._modulus -1 (True, in if)
Body of if (True part)	self/m.reset()
FEOOP			Modular_Counter.reset(self/m)
(nf) Inheritance	Counter.reset(self/m)
Method Body			self/m._value = 0

m._value is now 0

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Just the "interesting parts" (used above) of these classes.
See lecture note for all details.

class Counter:
    ...

    def reset(self):		# NOT overridden in Modular_Counter
        self._value = 0
        
    def inc(self):		# Overridden
        self._value += 1
        
    def value_of(self):         # NOT overridden in Modular_Counter
        return self._value
    
    
class Modular_Counter(Counter):
    ...

    def inc(self):
        if self.value_of() == self._modulus - 1:
            self.reset()
        else:
            Counter.inc(self)