ArrayLiteralContent : Expression
    ArrayLiteralContent : Expression COLON Expression

def p_ArrayLiteralContent(p):
    '''
    ArrayLiteralContent : Expression
    ArrayLiteralContent : Expression COLON Expression
    '''
    if len(p) < 3:
        p[0] = ArrayLiteralContent(None, p[1])
    else:
        p[0] = ArrayLiteralContent(p[1], p[3])