import re


def split_into_words(in_str:str) -> list:
    """
    Helper function splitting the given string into a list of words. Hyphens are considered to separate words.
    :param in_str: The string to split into words
    :return: A list of words in the given string
    """
    in_str = re.sub('[/ \-\t\n]+', ' ', in_str).strip().lower()
    in_str = ''.join([c for c in in_str if c.isalpha() or c == ' '])
    return [word.strip() for word in in_str.strip().split(' ') if len(word) > 0]