#! /usr/bin/env python3
# encoding: utf-8

class compare_float:
	"""
	Sets .lt, .eq or .gt iff A is less than, equal or greather than B.
	"""
	
	def __init__(self, A, B, epsilon=1e-12):
		self.lt = False
		self.le = True
		self.eq = False
		self.ge = True
		self.gt = False
		
		if A < (B - epsilon):
			self.lt = True
			self.ge = False
		elif A > (B + epsilon):
			self.gt = True
			self.le = False
		
		if abs(A - B) < epsilon:
			self.eq = True
		
		# convenience
		self.less = self.lt
		self.less_or_equal = self.le
		self.equal = self.eq
		self.greater_or_equal = self.ge
		self.greater = self.gt

if __name__ == '__main__':
	x = compare_float(1, 2, 0.5)
	assert x.lt and x.less and not (x.le or x.ge)
	x = compare_float(2, 2, 0.5)
	assert x.eq and x.le and x.ge and not (x.lt or x.gt)
	x = compare_float(3, 2, 0.5)
	assert x.gt and not (x.ge or x.eq or x.lt)