You're assuming split was written to easily count the number of tokens.

Um. Nope. I made no such assumption. Thats purely your assumption.

I agree part way. I can see the thought train that leads to some of it. I've written this function that splits strings. It can be called in 3 contexts. What is the logical thing to do in those contexts?

1. List context: return the list of bits.
2. Scalar context: Return how many bits.
3. Void context: He's asked us to split, but wants nothing back. I guess we could stick the bits in @_ and let him access them there.

But, I fail to see a good (nor even a bad) use case for returning the count AND sticking the bits in @_.

Maybe there's one, but I just don't see it. If it stuck them in @F per -a, maybe.