class Trinary: 
	"""Trinary word"""

	def __init__(self, value, convert):		
		#Convert to base 3 if necessary
		if convert:
			value = self.__converti(value)
		self.value = value
		
		#Check max lenght
		if self.lenght > 10:
			raise OverflowError("Trit word limit exceeded: max 10 (passed %d)"
					% self.lenght)
	
	def __converti(self, decimal):
		"""Return decimal value of the passed trinary."""
		trinary = []
		if decimal == 0:
			return [0]
		while decimal > 0:
			trinary += decimal % 3,
			decimal //= 3
		return trinary[::-1]
	
	#Operators override

	def __iter__(self):
		trilist = (int(i) for i in self.value)
		return iter(trilist)
		
	def __str__(self):
		return self.value
	
	def __repr__(self):
		return self.value
	
	def __setattr__(self, name, value):
		"""
		Assegna entrambi i valori (decimal e trinary) quando almeno uno
		cambia.
		"""
		if name == "value":
			if type(value) is list:
				value = "".join([str(i) for i in value])
				self.__dict__["value"] = value
			elif type(value) is str:
				self.__dict__["value"] = value
			elif type(value) is int:
				self.__dict__["value"] = str(value)
			self.__dict__["decimal"] = int(self.value, base=3)
			self.__dict__["lenght"] = len(self.value)
		elif name == "decimal":
			if type(value) is int:
				self.__dict__["value"] = str(self.decimal)
				self.__dict__["decimal"] = value
			elif type(value) is list:
				value = "".join([str(i) for i in value])
				self.__dict__["value"] = value
				self.__dict__["decimal"] = int(self.value, base=3)
			self.__dict__["lenght"] = len(self.value)
				
	def __getitem__(self, index):
		return self.value[index]	
	
	#Math operators override

	def __add__(self, other):
		try:
			return Trinary(self.decimal + other.decimal, True)
		except AttributeError:
			return Trinary(self.decimal + other, True)

	def __iadd__(self, other):
		try:
			return self + other
		except AttributeError:
			return self.decimal + other

	def __sub__(self, other):
		try:
			return Trinary(self.decimal - other.decimal, True)
		except AttributeError:
			return Trinary(self.decimal - other, True)

	def __isub__(self, other):
		return self - other

	def __mul__(self, other):
		try:
			return Trinary(self.decimal * other.decimal, True)
		except AttributeError:
			return Trinary(self.decimal * other, True)

	def __imul__(self, other):
		return self * other

	def __mod__(self, other):
		try:
			return Trinary(self.decimal % other.decimal, True)
		except AttributeError:
			return Trinary(self.decimal % other, True)

	def __imod__(self, other):
		return self % other

	def __truediv__(self, floor):
		try:
			return Trinary(self.decimal / other.decimal, True)
		except AttributeError:
			return Trinary(self.decimal / other, True)

	def __itruediv__(self, other):
		return self / other

	def __floordiv__(self, other):	
		try:
			return Trinary(self.decimal // other.decimal, True)
		except AttributeError:
			return Trinary(self.decimal // other, True)

	def __ifloordiv__(self, other):
		return self // other

	def __lt__(self, other):
		try:
			return self.decimal < other.decimal
		except AttributeError:
			return self.decimal < other

	def __le__(self, other):
		try:
			return self.decimal <= other.decimal
		except AttributeError:
			return self.decimal <= other

	def __eq__(self, other):
		try:
			return self.decimal == other.decimal
		except AttributeError:
				return self.decimal == other

	def __ne__(self, other):
		try:
			return self.decimal != self.other
		except AttributeError:
			return self.decimal != other

	def __gt__(self, other):
		try:
			return self.decimal > other.decimal
		except AttributeError:
			return self.decimal > other

	def __ge__(self, other):
		try:
			return self.decimal >= other.decimal
		except AttributeError:
			return self.decimal >= other
	
class Trilist:
	"""Trinary word list"""

	def __init__(self, trilist, convert):
		"""Trinary list inizialization."""
		self.valori ={a:trin(b, convert) for a, b in enumerate(trilist)}
	
	#Operators override
	
	def __setitem__(self, index, value):
		try:
			self.valori[index.decimal] = value
		except AttributeError:
			self.valori[index] = value
		
	def __getitem__(self, index):
		try:
			return self.valori[index.decimal]	
		except AttributeError:
			return self.valori[index]
		except KeyError:
			return trin(0)

	def __str__(self):
		return self.valori.__str__()
	
	def __repr__(self):
		return self.valori

#Wrappers

def trin(value, convert=False):
	"""
	Returns a trinary word. Provide convert=True as a parameter if
	the value is decimal.
	"""
	return Trinary(value, convert)

def trinord(carattere):
	"""
	Returns the ordinal value of a character in a trinary word.
	"""
	return trin(ord(carattere), True)

def trinchr(trinary):
	"""
	Returns the ASCII character given a trinary word.
	"""
	return chr(trinary.decimal % 256)

def trinlist(trilist=[], convert=False): 
	"""
	Returns a trilist accessible by trinary indices given a list word.
	Provide convert=False as a parameter only if the elements of trilist
	are trinary. Do not use lists with mixed basis.
	"""
	return Trilist(trilist, convert)