| > I never said it is used extensively by most programs True, but to make use of Rc/Arc in Rust comparable to the use of GC in Java, almost evrery value would have to be wrapped in one, something I would think is quite rare. > only that most programs do use it I would still be interested in seeing statistics for this though. I have only ever used Arc once, and it was only to share a Mutex containing the program's database across threads. > What's the difference between a standard library and a runtime? I would say there are three main differences:
- A runtime is (usually?) not optional - see languages like C#/Java/Python that require some sort of higher 'power' to manage their execution (interpreting/JITing code, GC management, etc), or crt0 - compared to a standard library which is just some extra code - see the C standard library function strlen()
- A standard library can generally be implemented in the language itself. I think this is where the distinction starts to get a little fuzzier, with languages like Roc (its standard library is implemented in Zig), and Haskell (I would assume much of the side-effecty code like the implementation of IO is in C)
- The purpose of a standard library is generally to provide 'helper' code that you wouldn't want to write yourself, e.g. Vec<T>, HashMap<T>, filesystem functions, etc. On the other hand, the purpose of a runtime is, per the first point, to manage the execution of the language, etc. > I never said that LLVM was a JVM True again, my point was worded badly. I didn't mean to suggest you thought LLVM was a JVM, rather to draw a distinction between LLVM and a Java/.NET style VM. LLVM used to stand for Low Level Virtual Machine, and the JVM has instructions like instanceof (which, fairly obviously, checks if a reference is an instance of the named class, array, or interface type). They operate at quite different abstraction levels, and the JVM is a lot more similar to the CLR. > Now, it is true that Rust is typically (though not always) compiled to native code AOT I would be genuinely interested in finding about a JIT compiler for Rust. EDIT: it's worth me mentioning none of this is backed by any formal education (I'm 18), so it is very possibly wrong. |