file.sc

class BinAccum(object):
    
	def __init__(self):
		self.number = 0
		self.place = 0

	def __neg__(self):
		self.place += 1
		return self
		
	def __pos__(self):
	    self.number += 2**self.place
	    self.place += 1
	    return self


class BinLitaral(object):
    
	def __neg__(self):
		return -BinAccum()
		
	def __pos__(self):
		return +BinAccum()

	def __sub__(self, other):
		if isinstance(other, BinAccum):
			return (-other).number
		else:
			return 0
	
	def __add__(self, other):
		if isinstance(other, BinAccum):
			return (+other).number
		else:
			return 1

i = BinLitaral()

if __name__ == "__main__":
    assert i+-+-+-i == 42