[sqeaky]

Underneath the hood that's a C string, and the four points to the null terminator, so it's indexable. And that's why you get an empty string if you point exactly one past the end.

That's why if you put five or more in for the first index it fails to produce a result entirely. I think I might I preferred an exception or a failure code being returned, but I can't say the current design is truly awful.

[randomdata]

> That's why if you put five or more in for the first index it fails to produce a result entirely.

Where does this come from? Are these discrepancies stemming from different Ruby implementations/versions behaving differently? "abc".slice(5, 10) returns the same value as "abc".slice(4, 10) [which, curiously, does not return the same value as the original comment] under MRI 2.6.1 that I had handy.

[sqeaky]

I believe I got it from the book Ruby under the microscope. Which looked at what is now a really old version of Ruby, and if they changed it to make a API more consistent that's probably good.