[Info-vax] Rust as a HS language, was: Re: Quiet?

[Dan Cross]

In article <jb2t2oF49voU1 at mid.individual.net>,
Bill Gunshannon  <bill.gunshannon at gmail.com> wrote:
>So, I have been following this discussion for some time now.  I have
>never used Rust.  I have never even looked at Rust. But I do have one
>question.
>
>Just what is it that Rust can do that none of the already existing
>languages could do?

There are three main interacting features that are unique in
their combination in the language that Rust brings to bear:

1) Lifetimes attached to pointers are a first-class primitive in
   the language.  They are literally part of the type.
   References cannot outlive the objects they refer to.
2) A compile-time borrow checker that ensures that either a
   single mutable reference to an object, or one or more
   immutable references.  In safe rust code, data races are
   impossible.
3) Object ownership is a first-class primitive in the language,
   and every object has exactly one owner.  All objects must be
   initialized before use.  Dangling pointers and uninitialized
   pointers are 

The combination of these things is incredibly powerful, and
gives you type and memory safety _without garbage collection_.
The result is that you program as if you were using a managed
language, but with explicit control over memory allocation.

You can even do this on bare metal.  The langauge gives you a
high degree of abstraction with the "core" library, even in
kernel mode.  In that context, it's actually quite pleasant to
use.

	- Dan C.