cond.py

#!/usr/bin/python3
import math
import operator
from parser import expr
from string import ascii_uppercase, ascii_lowercase, digits
from inspect import currentframe

class Cond:

	'''
	Cond class
	Creates a Cond object, whose options are passed as unnamed arguments
	All options must be of the same built-in numeric type (int, float or complex)
	Main option is chosen to be the first passed argument, unless otherwise specified by the "mainpos" keyword argument
	
	A Cond object acts just like a numeric type in most cases, however it has some additional methods
	Calling len() on a Cond object will return the amount of options that it currently holds
	The options of a Cond object can be accessed, reassigned or deleted using the [] syntax, with the exception of the main option
	Using the "in" keyword on a Cond object will return True if the given value is in the options, otherwise False
	A Cond object can be used as an iterable, which is equivalent to using the list of options in place of the Cond object
	Using the append() method on a Cond object will add a new option to that object, so long it doesn't already exist
	Using the remove() method on a Cond object will remove an existing option from that object, so long it isn't the main option
	Using the index(value) method on a Cond object will return an integer representing the index of that value in the Cond object's options
	Cond objects can be passed to the require function, which will edit their main option based on the given expression
	The require function cannot affect the options of a Cond object, it can only change its main option to a different one from
	the available options
	'''

	def __init__(self, *args, **kwargs):

		self.ID = id(self)

		#check if kwargs are correct
		for kwarg in kwargs:
			if kwarg not in {"mainpos", "range"}:
				raise ValueError("Cond: unknown keyword argument {}".format(kwarg))

		#raise error if no arguments were given
		if len(args) == 0 and "range" not in kwargs:
			raise ValueError("Cond: need at least one argument at initialization")

		#setup mainpos kwarg
		if "mainpos" in kwargs:
			self.__MAINPOS = kwargs["mainpos"]
		else:
			self.__MAINPOS = 0

		#error check range kwarg if it's tuple (if it is int, it's ready to use in range() function)
		if "range" in kwargs and type(kwargs["range"]) is not int:
			if type(kwargs["range"]) is not tuple or not len(kwargs["range"]) or len(kwargs["range"]) > 3:
				raise ValueError("Cond: keyword argument \"range\" must be int, or tuple of length 1-3")

			for num in kwargs["range"]:
				if type(num) is not int:
					raise ValueError("Cond: keyword argument \"range\" can only include numbers of type int, not {}".format(type(num)))

		#error check regular numeric arguments
		if "range" in kwargs:
			argtype = int
		else:
			if self.__MAINPOS >= len(args):
				raise ValueError("Cond: keyword argument \"mainpos\" out of range")
			argtype = type(args[self.__MAINPOS])

		if argtype not in {int, float, complex}:
			raise TypeError("Cond: arguments must all be numeric types")

		for arg in args:
			if type(arg) is not argtype:
				raise TypeError("Cond: arguments must all be of the same type")

		#save the option type in __TYPE, the values in __VALS and the main option in __MAIN
		self.__TYPE = argtype
		self.__VALS = []

		#if range keyword was provided, add the specified range to __VALS
		if "range" in kwargs:
			if type(kwargs["range"]) is int:
				kwargs["range"] = (kwargs["range"],)

			if len(kwargs["range"]) == 1:
				self.__VALS.extend(range(kwargs["range"][0]))
			elif len(kwargs["range"]) == 2:
				self.__VALS.extend(range(kwargs["range"][0], kwargs["range"][1]))
			else:
				self.__VALS.extend(range(kwargs["range"][0], kwargs["range"][1], kwargs["range"][2]))

		if len(self.__VALS) and len(args):
			self.__MAINPOS = len(self.__VALS)

		for arg in args:
			self.__VALS.append(arg)

		if not len(self.__VALS):
			raise ValueError("Cond: object cannot be initialized with no options")

		if self.__MAINPOS >= len(self.__VALS):
			raise ValueError("Cond: keyword argument \"mainpos\" out of range")

		self.__MAIN = self.__VALS[self.__MAINPOS]

	def all(self):
		return list(self.__VALS)

	def _setmain(self, op_index):
		self.__MAIN = self.__VALS[op_index]
		self.__MAINPOS = op_index

	def __get__(self):
		return self.__MAIN

	def __eq__(self, other):
		if type(other) is type(self):
			return self.__MAIN == other.__MAIN
		else:
			return self.__MAIN == other

	def __ne__(self, other):
		if type(other) is type(self):
			return self.__MAIN != other.__MAIN
		else:
			return self.__MAIN != other

	def __lt__(self, other):
		if type(other) is type(self):
			return self.__MAIN < other.__MAIN
		else:
			return self.__MAIN < other

	def __gt__(self, other):
		if type(other) is type(self):
			return self.__MAIN > other.__MAIN
		else:
			return self.__MAIN > other

	def __le__(self, other):
		if type(other) is type(self):
			return self.__MAIN <= other.__MAIN
		else:
			return self.__MAIN <= other

	def __ge__(self, other):
		if type(other) is type(self):
			return self.__MAIN >= other.__MAIN
		else:
			return self.__MAIN >= other

	def __pos__(self):
		return self.__MAIN

	def __neg__(self):
		return -self.__MAIN

	def __abs__(self):
		return abs(self.__MAIN)

	def __invert__(self):
		return ~self.__MAIN

	def __round__(self):
		return round(self.__MAIN)

	def __floor__(self):
		return math.floor(self.__MAIN)

	def __ceil__(self):
		return math.ceil(self.__MAIN)

	def __trunc__(self):
		return math.trunc(self.__MAIN)

	def __add__(self, other):
		if type(other) is type(self):
			return self.__MAIN + other.__MAIN
		else:
			return self.__MAIN + other

	def __sub__(self, other):
		if type(other) is type(self):
			return self.__MAIN - other.__MAIN
		else:
			return self.__MAIN - other

	def __mul__(self, other):
		if type(other) is type(self):
			return self.__MAIN * other.__MAIN
		else:
			return self.__MAIN * other

	def __floordiv__(self, other):
		if type(other) is type(self):
			return self.__MAIN // other.__MAIN
		else:
			return self.__MAIN // other

	def __truediv__(self, other):
		if type(other) is type(self):
			return self.__MAIN / other.__MAIN
		else:
			return self.__MAIN / other

	def __mod__(self, other):
		if type(other) is type(self):
			return self.__MAIN % other.__MAIN
		else:
			return self.__MAIN % other

	def __divmod__(self, other):
		if type(other) is type(self):
			return divmod(self.__MAIN, other.__MAIN)
		else:
			return divmod(self.__MAIN, other)

	def __pow__(self, other):
		if type(other) is type(self):
			return self.__MAIN ** other.__MAIN
		else:
			return self.__MAIN ** other

	def __lshift__(self, other):
		if type(other) is type(self):
			return self.__MAIN << other.__MAIN
		else:
			return self.__MAIN << other

	def __rshift__(self, other):
		if type(other) is type(self):
			return self.__MAIN >> other.__MAIN
		else:
			return self.__MAIN >> other

	def __and__(self, other):
		if type(other) is type(self):
			return self.__MAIN & other.__MAIN
		else:
			return self.__MAIN & other

	def __or__(self, other):
		if type(other) is type(self):
			return self.__MAIN | other.__MAIN
		else:
			return self.__MAIN | other

	def __xor__(self, other):
		if type(other) is type(self):
			return self.__MAIN ^ other.__MAIN
		else:
			return self.__MAIN ^ other

	def __radd__(self, other):
		return self + other

	def __rsub__(self, other):
		if type(other) is type(self):
			return other.__MAIN - self.__MAIN
		else:
			return other - self.__MAIN

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

	def __rfloordiv__(self, other):
		if type(other) is type(self):
			return other.__MAIN // self.__MAIN
		else:
			return other // self.__MAIN

	def __rtruediv__(self, other):
		if type(other) is type(self):
			return other.__MAIN / self.__MAIN
		else:
			return other / self.__MAIN

	def __rmod__(self, other):
		if type(other) is type(self):
			return other.__MAIN % self.__MAIN
		else:
			return other % self.__MAIN

	def __rdivmod__(self, other):
		if type(other) is type(self):
			return divmod(other, self)
		else:
			return divmod(other, self.__MAIN)

	def __rpow__(self, other):
		if type(other) is type(self):
			return other ** self
		else:
			return other ** self.__MAIN

	def __rlshift__(self, other):
		if type(other) is type(self):
			return other << self
		else:
			return other << self.__MAIN

	def __rrshift__(self, other):
		if type(other) is type(self):
			return other >> self
		else:
			return other >> self.__MAIN

	def __rand__(self, other):
		return self & other

	def __ror__(self, other):
		return self | other

	def __rxor__(self, other):
		return self ^ other

	def __iadd__(self, other):
		if type(other) is type(self):
			result = self.__MAIN + other.__MAIN
		else:
			result = self.__MAIN + other

		if not type(result) is self.__TYPE:
			raise TypeChangeError("Cond: operation would change main option type")

		self.__MAIN = result		
		self.__VALS[self.__MAINPOS] = self.__MAIN
		return self

	def __isub__(self, other):
		if type(other) is type(self):
			result = self.__MAIN - other.__MAIN
		else:
			result = self.__MAIN - other

		if not type(result) is self.__TYPE:
			raise TypeChangeError("Cond: operation would change main option type")

		self.__MAIN = result		
		self.__VALS[self.__MAINPOS] = self.__MAIN
		return self

	def __imul__(self, other):
		if type(other) is type(self):
			result = self.__MAIN * other.__MAIN
		else:
			result = self.__MAIN * other

		if not type(result) is self.__TYPE:
			raise TypeChangeError("Cond: operation would change main option type")

		self.__MAIN = result		
		self.__VALS[self.__MAINPOS] = self.__MAIN
		return self

	def __ifloordiv__(self, other):
		if type(other) is type(self):
			result = self.__MAIN // other.__MAIN
		else:
			result = self.__MAIN // other

		if not type(result) is self.__TYPE:
			raise TypeChangeError("Cond: operation would change main option type")

		self.__MAIN = result		
		self.__VALS[self.__MAINPOS] = self.__MAIN
		return self

	def __itruediv__(self, other):
		if type(other) is type(self):
			result = self.__MAIN / other.__MAIN
		else:
			result = self.__MAIN / other

		if not type(result) is self.__TYPE:
			raise TypeChangeError("Cond: operation would change main option type")

		self.__MAIN = result		
		self.__VALS[self.__MAINPOS] = self.__MAIN
		return self


	def __imod__(self, other):
		if type(other) is type(self):
			result = self.__MAIN % other.__MAIN
		else:
			result = self.__MAIN % other

		if not type(result) is self.__TYPE:
			raise TypeChangeError("Cond: operation would change main option type")

		self.__MAIN = result		
		self.__VALS[self.__MAINPOS] = self.__MAIN
		return self


	def __ipow__(self, other):
		if type(other) is type(self):
			result = self.__MAIN ** other.__MAIN
		else:
			result = self.__MAIN ** other

		if not type(result) is self.__TYPE:
			raise TypeChangeError("Cond: operation would change main option type")

		self.__MAIN = result		
		self.__VALS[self.__MAINPOS] = self.__MAIN
		return self

	def __ilshift__(self, other):
		if type(other) is type(self):
			result = self.__MAIN << other.__MAIN
		else:
			result = self.__MAIN << other

		if not type(result) is self.__TYPE:
			raise TypeChangeError("Cond: operation would change main option type")

		self.__MAIN = result		
		self.__VALS[self.__MAINPOS] = self.__MAIN
		return self

	def __irshift__(self, other):
		if type(other) is type(self):
			result = self.__MAIN >> other.__MAIN
		else:
			result = self.__MAIN >> other

		if not type(result) is self.__TYPE:
			raise TypeChangeError("Cond: operation would change main option type")

		self.__MAIN = result		
		self.__VALS[self.__MAINPOS] = self.__MAIN
		return self


	def __iand__(self, other):
		if type(other) is type(self):
			result = self.__MAIN & other.__MAIN
		else:
			result = self.__MAIN & other

		if not type(result) is self.__TYPE:
			raise TypeChangeError("Cond: operation would change main option type")

		self.__MAIN = result		
		self.__VALS[self.__MAINPOS] = self.__MAIN
		return self

	def __ior__(self, other):
		if type(other) is type(self):
			result = self.__MAIN | other.__MAIN
		else:
			result = self.__MAIN | other

		if not type(result) is self.__TYPE:
			raise TypeChangeError("Cond: operation would change main option type")

		self.__MAIN = result		
		self.__VALS[self.__MAINPOS] = self.__MAIN
		return self

	def __ixor__(self, other):
		if type(other) is type(self):
			result = self.__MAIN ^ other.__MAIN
		else:
			result = self.__MAIN ^ other

		if not type(result) is self.__TYPE:
			raise TypeChangeError("Cond: operation would change main option type")

		self.__MAIN = result		
		self.__VALS[self.__MAINPOS] = self.__MAIN
		return self

	def __int__(self):
		return int(self.__MAIN)

	def __float__(self):
		return int(self.__MAIN)

	def __complex__(self):
		return complex(self.__MAIN)

	def __oct__(self):
		return oct(self.__MAIN)

	def __index__(self):
		return self.__MAIN

	def __str__(self):
		return str(self.__MAIN)

	def __repr__(self):
		return repr(self.__MAIN)

	#__format__

	def __hash__(self):
		return hash(self.ID)

	def __nonzero__(self):
		return bool(self.__MAIN)

	def __dir__(self):
		return dir(Cond)

	def __len__(self):
		return len(self.__VALS)

	def __getitem__(self, ind):
		if type(ind) not in {int, slice}:
			raise TypeError("Cond: access indices must be integers or slices, not {}".format(type(ind)))

		elif type(ind) is int and ind >= len(self.__VALS):
			raise IndexError("Cond: index out of range")

		return self.__VALS[ind]

	def __setitem__(self, ind, value):
		if type(ind) is not int:
			raise TypeError("Cond: assignment indices must be integers, not {}".format(type(ind)))

		elif type(value) is not self.__TYPE:
			raise TypeError("Cond: object's type is {}, but value given was of type {}".format(self.__TYPE, type(value)))

		elif ind >= len(self.__VALS):
			raise IndexError("Cond: index out of range")

		elif ind == self.__MAINPOS:
			raise ValueError("Cond: object's current option cannot be changed by assignment")

		self.__VALS[ind] = value

	def __delitem__(self, ind):
		if type(ind) not in {int, slice}:
			raise TypeError("Cond: deletion indices must be integers or slices, not {}".format(type(ind)))

		elif type(ind) is int and ind >= len(self.__VALS):
			raise IndexError("Cond: index out of range")

		elif type(ind) is int and ind == self.__MAINPOS:
			raise ValueError("Cond: object's current option cannot be deleted")

		elif type(ind) is slice and self.__MAINPOS >= ind.start and self.__MAINPOS < ind.stop:
			raise ValueError("Cond: object's current option's index was contained in given slice, but cannot be deleted")

		del self.__VALS[ind]

	def __iter__(self):
		return iter(self.__VALS)

	def __contains__(self, value):
		return value in self.__VALS

	def __copy__(self):
		newObj = Cond(*self.__VALS, mainpos = self.__MAINPOS)
		return newObj

	def append(self, value):
		if type(value) is not self.__TYPE:
			raise TypeError("Cond.append(x): object's type is {}, while x's type is {}".format(self.__TYPE, type(value)))
		elif value in self.__VALS:
			raise ValueError("Cond.append(x): x contained in object")

		self.__VALS.append(value)

	def remove(self, value):
		if value not in self.__VALS:
			raise ValueError("Cond.remove(x): x not in options")
		elif value == self.__MAIN:
			raise ValueError("Cond.remove(x): x is main option")

		self.__VALS.remove(value)

	def index(self, value):
		if value not in self.__VALS:
			raise ValueError("Cond.index(x): x not in options")

		return self.__VALS.index(value)


class LinkedCond(Cond):

	'''
	LinkedCond object
	Acts exactly like a Cond object, with the exception that it remembers previous limitations set by require()
	Is "linked" to other LinkedCond objects that have had the same limitation(s) set on them
	Adds new methods:
	-> clearlims(): removes limitations from object, and all other LinkedCond objects linked to it
	-> getlims(): returns set of limitations for object; inside each expression, if the variable names for
	the objects involved are found, they will be used; otherwise, the variable names used when require() was
	called will be used
	'''

	def __init__(self, *args, **kwargs):
		super().__init__(*args, **kwargs)
		self.__LIMS = []

	def _addLim(self, lim):
		self.__LIMS.append(lim)

	def _getLimsRepr(self):
		return list(self.__LIMS)

	def clearlims(self):
		for limitation in list(self.__LIMS):
			for linked_cond in limitation[1]:
				linked_cond.__LIMS.remove(limitation)

	def getlims(self):
		lims = set()
		var_not_found = False
		for lim_repr in self.__LIMS:
			expression =  _interpretExpression(lim_repr[0], len(lim_repr[1]), return_str = True)

			variables_to_varnames = _mapVariablesToCond(expression, lim_repr[1])
			prev_scope = currentframe().f_back.f_locals

			for var in variables_to_varnames:
				for varname in prev_scope:
					if variables_to_varnames[var] is prev_scope[varname]:
						variables_to_varnames[var] = varname
					elif type(prev_scope[varname]) is dict:
						for key in prev_scope[varname]:
							if variables_to_varnames[var] is prev_scope[varname][key]:
								variables_to_varnames[var] = "{}[{}]".format(varname, key)

					else:
						try:
							for element in prev_scope[varname]:
								if element is variables_to_varnames[var]:
									variables_to_varnames[var] = "{}[{}]".format(varname, prev_scope[varname].index(element))
						except TypeError:
							pass

			new_expression = ""

			for c in expression:
				if c.isalpha():
					try:
						new_expression += variables_to_varnames[c]
					except TypeError:
						var_not_found = True
						break
				else:
					new_expression += c

			if var_not_found:
				lim = "{} {} ".format(expression, lim_repr[2])
			else:
				lim = "{} {} ".format(new_expression, lim_repr[2])

			if len(lim_repr[3]) > 1:
				lim += str(lim_repr[3])
			else:
				lim += str(lim_repr[3][0])

			lims.add(lim)

		return lims



'''
PRIVATE
Stores values that are reused by functions so they aren't constantly allocated and freed
'''
class _MainData:
	evaluation_signs = {"=": operator.eq, ">": operator.gt, ">=": operator.ge, "<": operator.lt, "<=": operator.le, "!=": operator.ne}
	operation_signs = {"+", "-", "*", "/", "%", "^"}
	accepted_characters = set(ascii_uppercase + ascii_lowercase + digits) | operation_signs | {" ", "(", ")"}



def require(expression, cond_objects, eval_sign, eval_num):

	'''
	require function
	Used to set limitations for Cond/LinkedCond objects
	Input arguments:
	-> expression: a mathematical expression to evaluate; essentially the "left part" of the equation
	every variable that is part of the expression must be single-letter; it corresponds to exactly one Cond object
	-> cond_objects: the Cond objects to replace the variables in the expression with; can be tuple of Conds or simply Cond
	must include exactly the same amount of arguments as variables in the expression
	LinkedCond and Cond objects cannot be used at the same time (it would link non-LinkedCond objects, which isn't possible)
	->eval_sign: evaluation sign to be used; must be =, >, >=, <, <=, !=
	->eval_num: evaluation number to be used; can be any numeric type or Cond, but not expression; 
	for != sign, multiple eval nums can be passed as a type tuple
	The require function will go through all combinations for the options of all involved Cond objects and attempt to find
	a combination, which satisfies the equation; if such options are found, the main option(s) of the Cond object(s) passed
	will be changed to those new options and True will be returned; otherwise, the Cond objects will not be changed in any way
	and False will be returned
	Similarly, for LinkedCond objects, all combinations which satisfy each limitation will be found; then, the "intersection" will
	be found (meaning a combination to satisfy all limitations); if such a combination exists, the main option(s) of all LinkedCond
	objects involved will be set to those; NOTE: LinkedCond objects, since they are linked, can be changed indirectly (refer to README)
	'''

	#if evaluation sign is unknown
	if eval_sign not in _MainData.evaluation_signs.keys():
		raise ValueError("require(): bad evaluation sign")
	#if evaluation number is of incorrect type
	elif type(eval_num) not in {Cond, LinkedCond, int, float, complex, tuple}:
		raise TypeError("require(): bad evaluation number")
	#if cond_objects is of incorrect type
	elif type(cond_objects) not in {tuple, Cond, LinkedCond}:
		raise TypeError("require(): bad cond_objects argument")

	if type(cond_objects) in {Cond, LinkedCond}:
		condtype = type(cond_objects)
		cond_objects = (cond_objects,)
	else:
		condtype = type(cond_objects[0])
		for cond_object in cond_objects:
			if type(cond_object) not in {Cond, LinkedCond}:
				raise TypeError("require(): bad cond_objects argument")
			elif type(cond_object) is not condtype:
				raise TypeError("require(): cannot evaluate expression with both Cond and LinkedCond objects")

	if type(eval_num) is not tuple:
		eval_num = (eval_num,)

	if len(eval_num) != 1 and eval_sign != "!=":
		raise ValueError("require(): expected single eval_num, but got multiple")

	#interpret expression given by user
	formula = _interpretExpression(expression, len(cond_objects))

	#if expression was wrong
	if formula is None:
		raise ValueError("require(): bad expression")

	#find total variables in expression
	variables_found = []
	total_variables = 0
	for c in expression:
		if c.isalpha() and c not in variables_found:
			total_variables += 1
			variables_found.append(c)

	#if number of variables is different than number of Cond objects, throw error
	if total_variables != len(cond_objects):
		raise ValueError("require(): number of Cond objects passed was different than number of individual variables in expression")

	#map single-letter variables to corresponding Cond objects
	variables_to_cond = _mapVariablesToCond(expression, cond_objects)

	#call recursive function which checks all combinations of options of all given Cond objects 
	#empty dicts need to be passed, because function is recursive, so it needs to pass data to deeper recursion levels
	if condtype is Cond:
		resulting_combinations = _findCombination(formula, variables_to_cond, len(variables_to_cond) - 1, len(variables_to_cond) - 1, {}, {}, eval_sign, eval_num, None)
	else:
		satisfied_limitations = set() #keep satisfied limitations here to not run more than once for each limitation
		resulting_combinations = [] #list showcasing the resulting combinations
		first_lim = True

		#get every object that's linked to given cond objects
		linked_cond_objects = list(cond_objects)
		for cond_object in cond_objects:
			for limitation in cond_object._getLimsRepr():
				for linked_cond_object in limitation[1]:
					exists = False
					for existing_object in linked_cond_objects:
						if existing_object is linked_cond_object:
							exists = True
							break
					if not exists:
						linked_cond_objects.append(linked_cond_object)

		#loop through every cond object currently linked
		for cond_object in linked_cond_objects:

			#for every limitation of current object
			for limitation in cond_object._getLimsRepr():

				#check if limitation hasn't already been satisfied
				isSatisfied = False
				for l in satisfied_limitations:
					if _limEquals(l, limitation):
						isSatisfied = True
						break

				if not isSatisfied:
					#interpret the limitation as a formula
					lim_formula = _interpretExpression(limitation[0], len(limitation[1]))
					#map variables of limitation expression to corresponding Cond objects
					lim_variables_to_cond = _mapVariablesToCond(limitation[0], limitation[1])
					#get set containing all combinations for Cond objects included in limitation
					result = _findCombination(lim_formula, lim_variables_to_cond, len(lim_variables_to_cond) - 1, len(lim_variables_to_cond) - 1, {}, {}, limitation[2], limitation[3], set())

					if not result:
						return False

					#if it is first time looping, keep all results
					if first_lim:
						resulting_combinations = result
						first_lim = False
					#else, keep only those results that existed before
					else:
						resulting_combinations = _updateResultingCombinations(resulting_combinations, result)

					satisfied_limitations.add(limitation)

		#get results of new equation given by user
		result = _findCombination(formula, variables_to_cond, len(variables_to_cond) - 1, len(variables_to_cond) - 1, {}, {}, eval_sign, eval_num, set())

		if not result:
			return False

		#keep only results that satisfy this equation too
		if first_lim:
			resulting_combinations = result
		else:
			resulting_combinations = _updateResultingCombinations(resulting_combinations, result)			

	#if None was returned, no combination was found
	if not resulting_combinations:
		return False

	result = resulting_combinations

	#if dict was returned, it contains IDs of objects and corresponding indexes
	#so for each Cond object, set their main option to given index
	if type(resulting_combinations) is dict:
		for CondObjID in resulting_combinations:
			for CondObj in cond_objects:
				if CondObj.ID == CondObjID:
					CondObj._setmain(result[CondObjID])
					break
	#else it is list, which means dealing with LinkedCond objects
	#so pick the first combination in resulting_combinations and set their main options to the corresponding option
	else:
		#pick first combination
		final_comb_dict = resulting_combinations[0]
		
		for cond_object in linked_cond_objects:
			#set new main option for LinkedCond object
			cond_object._setmain(final_comb_dict[cond_object.ID])

			#check if LinkedCond object was contained in given expression
			contained = False
			for passed_cond_object in cond_objects:
				if passed_cond_object.ID == cond_object.ID:
					contained = True
					break

			#if it was, add limitation to it
			if contained:
				cond_object._addLim((expression, cond_objects, eval_sign, eval_num))
			

	return True


'''
PRIVATE
Takes input_set of format: s = {((1, 2),), ((3, 4), (5, 6))}
Turns into list of dicts: l = [{1: 2}, {3: 4, 5: 6}]
Returns list of dicts
'''
def _convertToListOfDicts(input_set):
	result = []

	for tuple_item in input_set:
		repr_dict = {}
		for map_tuple in tuple_item:
			repr_dict[map_tuple[0]] = map_tuple[1]

		result.append(repr_dict)

	return result

'''
PRIVATE
Combines all combinations and returns new list
with all resulting combinations
'''

def _updateResultingCombinations(resulting_combinations, result):
	new_resulting_combinations = []

	for dict1 in resulting_combinations:
		for dict2 in result:
			#if all common keys for two dicts have same values
			if _checkCommonKeys(dict1, dict2):
				#create dict with all entries from both dicts
				dict1.update(dict2)
				#if dict isn't in new combinations list, add it
				if dict1 not in new_resulting_combinations:
					new_resulting_combinations.append(dict1)


	return new_resulting_combinations



'''
PRIVATE
Returns True if all common keys in two dicts have same value
Else False
(for no common keys, returns True)
'''
def _checkCommonKeys(dict1, dict2):
	all_common = True
	for key in dict1:
		if key in dict2:
			if dict1[key] != dict2[key]:
				all_common = False
				break

	return all_common


'''
PRIVATE
Accepts given expression and given cond_objects as arguments
Maps each individual single-letter variable to a given cond object
Returns dictionary with keys mapped to values
'''
def _mapVariablesToCond(expression, cond_objects):

	variables_to_cond = {}
	i = 0
	for c in expression:
		if c.isalpha() and c not in variables_to_cond.keys():
			variables_to_cond[c] = cond_objects[i]
			i += 1

	return variables_to_cond


'''
PRIVATE
changes expression slightly and parses it using parser.expr, returns expression in code that can be evaluated with eval()
'''
def _interpretExpression(expression, cond_obj_amount, return_str = False):

	n_expression = ""

	for i in range(len(expression)):
		#remove spaces from expression
		if expression[i] != " " and expression[i] != "^":
			n_expression += expression[i]
		elif expression[i] == "^":
			n_expression += "**"

		#unknown character in expression
		if expression[i] not in _MainData.accepted_characters:
			return None

		#if number is followed by letter or letter is followed by letter, multiplication is implied
		if i != len(expression) - 1 and ((expression[i].isdigit() and (expression[i + 1].isalpha() or expression[i + 1] == "(")) or (expression[i].isalpha() and (expression[i + 1].isalpha() or expression[i + 1].isdigit() or expression[i + 1] == "("))):
			n_expression += "*"

	if not return_str:
		formula = expr(n_expression).compile()
		return formula

	return n_expression

'''
PRIVATE
recursive function, runs a single test of the equation for all combinations of numbers of all passed Cond objects
if combination is found, a dictionary is returned containing the Cond objects as keys and the indexes of the new main number as values
if no combination is found, None is returned
Arguments:
formula -> formula in code, executable with eval(), created by _interpretExpression
variables_to_cond -> dict mapping single-letter variables to the Cond object they represent
max_recursion_level -> highest level of recursion, essentially is the amount of total Cond objects -1
recursion_level -> current recursion level, reduced by one every recursive call, until it hits 0
numbers -> dict mapping the single_letter variables to the value that they will be tested as
indexes -> dict mapping the Cond object IDs to the index of the current option, so it can be returned if the option combination satisfies the equation
eval_sign -> the evaluation sign
eval_num -> the evaluation number(s)
combination_set -> can be one of two things:
	* None: if it is None, the first combination found will be returned in form of the indexes dict
	* set: if it is set, every combination dict found will be converted to tuple, and added to that set
	all available combinations will be found; the return value will be list of dicts (essentially, _convertToListOfDicts will be called on the set)
'''
def _findCombination(formula, variables_to_cond, max_recursion_level, recursion_level, numbers, indexes, eval_sign, eval_num, combination_set):

	keys = tuple(variables_to_cond.keys())
	
	#get Cond object to run loop for
	CondObj = variables_to_cond[keys[recursion_level]]
	for number in CondObj:

		#if this is the highest recursion level, reset the dictionaries to run again
		if recursion_level == max_recursion_level:
			numbers = {}
			indexes = {}

		#map the single-letter variable to the number
		numbers[keys[recursion_level]] = number
		#map the Cond object's id to the index of the number in it 
		#(if Cond object is mapped instead of id, two Cond objects with same main value will be the same entry and overwrite each other)
		indexes[id(CondObj)] = CondObj.index(number)

		#if all the for loops have been run
		if recursion_level == 0:			

			#if combination satisfies equation, return the indexes or add them to given set
			if _testEquation(formula, numbers, eval_sign, eval_num):
				if type(combination_set) is set:
					combination_set.add(tuple(indexes.items()))
				else:
					return indexes

		else:
			#get the result from deeper recursion level
			result = _findCombination(formula, variables_to_cond, max_recursion_level, recursion_level - 1, numbers, indexes, eval_sign, eval_num, combination_set)
			#if the result isn't None, a combination was found and combination set was not None, so return it to higher recursion level or to calling function
			if result:
				return result

	#if recursion level is max, it means all calls ended, so return the combination set
	if recursion_level == max_recursion_level and combination_set:
		return _convertToListOfDicts(combination_set)

	#if recursion level isn't max but indexes haven't been returned, return None (either no combination was found, or it was added to set)
	return None


'''
PRIVATE
tests if given equation is true
arguments required come directly from recursion level 0 of _findCombinations
returns True if given combination satisfies equation, else False
'''
def _testEquation(formula, numbers, eval_sign, eval_num):
	#set all the values for the single-letter variables
	for variable in numbers:
		exec("{} = {}".format(variable, numbers[variable]))
	#calculate the expression result
	try:
		equation_result = eval(formula)
	#if ZeroDivisionError, then combination of numbers cannot be right
	except ZeroDivisionError:
		return None
	#if the result satisfies all evaluations (with all given eval_nums), return True, else False
	satisfies = True
	for num in eval_num:
		if not _MainData.evaluation_signs[eval_sign](equation_result, num):
			satisfies = False
			break

	return satisfies
'''
PRIVATE
returns true if the two passed limitations are equal
'''
def _limEquals(lim1, lim2):
	if lim1[0] != lim2[0]:
		return False

	if len(lim1[1]) != len(lim2[1]):
		return False

	if lim1[2] != lim2[2]:
		return False

	if len(lim1[3]) != len(lim2[3]):
		return False

	i = 0
	while i < len(lim1[1]):
		if lim1[i] is not lim2[i]:
			return False
		i += 1

	i = 0
	while i < len(lim1[3]):
		if lim1[i] != lim2[i]:
			return False
		i += 1

	return True


'''
PRIVATE
TypeChangeError: thrown whenever an operation onto a Cond object (usually incrementing, decrementing, etc)
would change its type; for instance: a = Cond(1,2,3); a += 1.1; would change type of main option of object
to float from int, so it is not possible
'''
class TypeChangeError(Exception):
	pass