Tail Recursive

README.md

A Decorator class for Tail Recursive Optimisation.
Written by George Sakkis here.

rec.py

class tail_recursive(object):
	
	def __init__(self, func):
		self.func = func
		self.firstcall = True
		self.CONTINUE = object()

	def __call__(self, *args, **kwd):
		if self.firstcall:
			func = self.func
			CONTINUE = self.CONTINUE
			self.firstcall = False
			try:
				while True:
					result = func(*args, **kwd) 
					if result is CONTINUE: # update arguments
						args, kwd = self.argskwd
					else: # last call
						return result
			finally:
				self.firstcall = True
		else: # return the arguments of the tail call
			self.argskwd = args, kwd
			return self.CONTINUE