Although regular expressions could work, using split can be much easier and cleaner in certain circumstances if it had this functionality. When you have alot (thousands) of "one-time delimeters" in a file that you are working with, you could just stick them in an array and pass it to split. With regexes you would have to write a mechanism to create the entire regular expression for you (not particularly clean) or create a loop capturing up to the next delimeter per iteration (probably less efficient although not really difficult). I just think this would be useful (at least to me), and adding it to split seemed natural given split's power and usefulness.