import re


def splitExpression(expression):
    """
    Parse a license expression into its constituent identifiers.

    Arguments:
        - expression: SPDX license expression
    Returns: array of split identifiers
    """
    # remove parens and plus sign
    e2 = re.sub(r'\(|\)|\+', "", expression, flags=re.IGNORECASE)

    # remove word operators, ignoring case, leaving a blank space
    e3 = re.sub(r' AND | OR | WITH ', " ", e2, flags=re.IGNORECASE)

    # and split on space
    e4 = e3.split(" ")

    return sorted(e4)