Sure, reversing slices of say integers makes lots of sense, people definitely use that. I don't remember enough Go to know how tricky that is - presumably it is not a built-in feature?
Rust's slices have reverse() but the implementation is a little hairier than you might expect: https://doc.rust-lang.org/src/core/slice/mod.rs.html#625 explains why, it wants to persuade LLVM that the things we're swapping are definitely different things, so it cuts the slice in half (if there's an odd middle element no matter, it needn't move anywhere by definition) and swaps between halves, so that LLVM can see OK, this necessarily is two different things, no aliasing is possible.
I can't think an interviewer is expecting you to show that unless you're interviewing for a job working on optimisations in the compiler or something.
Fair I guess - of those I only used Fortran and not in an environment which supported the colon syntax. (Once you've chosen the wrong way to address array elements of course you'll end up with the wrong way to denote bounds, to take the contrapositive of the classic Djikstra note.)
But in this thread we're talking about Go - and the syntax is also used in Python and Ruby and with the same semantics `..` in Rust - and above all else the notation was clear from my question when I explicitly said those sets were disjoint - and that question is the much more interesting thing, I think?
Why LLVM needs this explaining? Probably somewhere an optimiser could inspect something and it doesn't.
Rust cuts the slice in half and swaps between the halves, so probably LLVM doesn't convince itself that if you did those swaps directly they aren't ever aliased, but once there are two slices which can't overlap it can see it's fine.
Rust's slices have reverse() but the implementation is a little hairier than you might expect: https://doc.rust-lang.org/src/core/slice/mod.rs.html#625 explains why, it wants to persuade LLVM that the things we're swapping are definitely different things, so it cuts the slice in half (if there's an odd middle element no matter, it needn't move anywhere by definition) and swaps between halves, so that LLVM can see OK, this necessarily is two different things, no aliasing is possible.
I can't think an interviewer is expecting you to show that unless you're interviewing for a job working on optimisations in the compiler or something.