Implementing typestate

[Ola Fosheim Grøstad via Digitalmars-d]

On Tuesday, 15 September 2015 at 20:01:16 UTC, Meta wrote:
> On Tuesday, 15 September 2015 at 18:30:34 UTC, Ola Fosheim 
> Grøstad wrote:
>> It is the same type of concept. Typestate, effect system, 
>> linear typing, behavioural typing. It is no doubt the future 
>> for type systems, but also demanding. I've tried to raise 
>> awareness about it before, but no takers:
>>
>> http://forum.dlang.org/post/ovoarcbexpvrrceysnrs@forum.dlang.org
>
> If I remember correctly Rust *did* have a typestate system very 
> early on but it was done away with in favour of the borrow 
> checker.

Yeah, I've seen the Rust creator write about how they started out 
with all whistles and bells with the intent of having a full blow 
effect system. Then realized that they had to make things simpler 
and focus on memory management because that was the most critical 
feature. Probably a wise strategy to go for simplicity and hit 
version 1.0 sooner.

Having a simple core language is usually a good idea. I see now 
in the rust forums that people use the borrow checker for other 
things than memory, like tracking what thread you are in:

https://users.rust-lang.org/t/my-gamedever-wishlist-for-rust/2859/7