last_token := queue.peek_back(operator_stack)
			last_token_importance := get_operator_importance(last_token^)

			for queue.len(operator_stack^) != 0 {
				last_token := queue.peek_back(operator_stack)
				last_token_importance := get_operator_importance(last_token^)

				// If operators importance is lower than the last ones on the stack (or equal)
				// and operator is not ^, pop last operator from stack to ast
				if current_token_importance <= last_token_importance {
					append(&ast, queue.pop_back(operator_stack))
				} else {
					//append(&ast, token)
					queue.push_back(operator_stack, token)
					break
				}
			}

			// If operators importance is lower than the last ones on the stack (or equal)
			// and operator is not ^, pop last operator from stack to ast
			if (current_token_importance <= last_token_importance) {
				append(&ast, queue.pop_back(operator_stack))

			if queue.len(operator_stack^) == 0 {

			} else {
				queue.push_back(operator_stack, token)