I'm pretty sure you're right on all counts; I'm not even sure that shared immutable borrows would work under the very simple transform given in the README.
Edit: Also, the user-facing language doesn't seem to have linearity at all, i.e. all values may be cloned. But linearity is something that people use to guarantee certain invariants all the time in Rust (and ATS, I've heard), so this seems like a misstep. It also means that memory allocation is implicit, which makes things less predictable for users.
yes, i found the first example quite surprising. there doesn't seem to be any request to copy the string; it is simply unintuively copied/produced three times. i would prefer the language have some kind of `dup` or something, which gives you an additional reference to the object.
as it stands, it has transferred allocation from the runtime to the compiler. but the objective is to put it into the hands of the developer, since only then is it known when reading and writing code.
i begin to suspect that a typed joy may be more practical (or rather: match my desired improvements) than clarifying allocations in haskell.
Edit: Also, the user-facing language doesn't seem to have linearity at all, i.e. all values may be cloned. But linearity is something that people use to guarantee certain invariants all the time in Rust (and ATS, I've heard), so this seems like a misstep. It also means that memory allocation is implicit, which makes things less predictable for users.