It is nice to have a connection between abstractions and hardware, because it makes it easier to reason about performance, which in turn makes it easier to achieve great performance.
Now, not everybody actually need great performance, so some distance between hardware and abstraction is ok, but the amount depends on the use case.
Well, I agree, that's why we have both low and high level languages. High level languages, setting you free from the actual constraints of the underlying machine, allow you to define abstractions that can increase productivity greatly - that's their whole point of existence.
I mean I don't see people complaining how you don't need to manually manage memory in SQL expressions.
> I mean I don't see people complaining how you don't need to manually manage memory in SQL expressions.
Well, they don't complain about not having to manually control the low-level bits of query execution, but later they frequently complain about performance problems. And then they add hints, setup buffer sizes, indexes, etc.
Also, Rust (and to some degree C++) shows that you can have both very high-level, productive abstractions and low-level control. They call that zero-cost abstractions. The price to pay is a steeper learning curve, but not actual productivity or final performance.
This is the most exciting part about Rust actually. I know how to write Kotlin, Scala, Java or C# code that's close in performance to C or C++. But this will be ugly, unsafe and hard to maintain, non-idiomatic code. Rust gives ability to write code that has almost Python-like expressivity but is still fast as if it were hand-optimised loops and pointers.
I'm not sure what your point is. I feel we may have a different idea of what very high level abstraction means in programming languages.
Just about everything in software engineering is a compromise of sorts. Not knowing Rust or C++, I doubt they're as high level as something like Haskell or domain specific languages like SQL. Are monads first class citizens on C++? Type classes? Generalized Algebraic Data types? Parametric polymorphism & pattern matching? And so on.
Would you really achieve the same amount of type level guarantees, equally concise control flow and concurrency on C++ with an equal amount of lines of code as would be possible on Haskell? If not, then there obviously is a productivity penalty. Just like on Haskell there is that performance penalty for not being able to drop down close to the metal.
From what I can tell, these languages are not aiming to be very high abstraction level languages but instead solid systems level languages with some convenient abstractions and design patterns baked in from higher level languages.
Sticking only to some zero-cost abstractions limits how high level abstractions it is possible to bring to the language. This in turn limits productivity.
Rust is very strong in its ability to build extremely powerful abstractions. With built-in compile-time procedural metaprogramming I could risk a statement that in some domains it may be actually even higher level than Haskell. Maybe its type system can't prove all the same guarantees as Haskell, but on the other hand, Haskell can't prove some guarantees that Rust can. They offer different set of abstractions with some overlap (e.g. first class type classes and ADTs). If is really hard to say which one is higher level. They are just different.
Anyway, type safety is not the same as productivity. If it was, then nobody would use Python or Ruby and everybody would use Idris. I became much more productive quickly in Rust than Haskell.
Interesting, what kind of guarantees does Rust give that Haskell's abstractions cannot do?
Haskell also has metaprogramming in terms of Generics and Template Haskell, allowing you to create custom DSLs and such. Sadly, it kind of leads to pretty ridiculous compile times and mixed editor support so I'm trying to avoid that.
We should remember productivity is really subjective and not the same thing as high level abstractions. We're typically the most productive on the language we have the most exposure to, whatever it may be.
> We should remember productivity is really subjective and not the same thing as high level abstractions. We're typically the most productive on the language we have the most exposure to, whatever it may be.
I agree with you on this we are most productive in the language with most exposure.
Indeed many in Rust community do not realize that the LLVM infrastructure they use for Rust to make its code executable by real hardware is itself written in C++.
Rust is still miles away to compile itself and may not happen. So survival of Rust is dependent on progress of C and C++. So I doubt it is even be viable to call it their replacement.
> Indeed many in Rust community do not realize that the LLVM infrastructure they use for Rust to make its code executable by real hardware is itself written in C++.
And the operating system is written in C, and the CPU in VHDL (or sth similar). Compiling itself is a property that only academics take care of. LLVM and C are not going anywhere anytime soon. There are more important things to do now. That's why Rust is already much more loved and popular language than Haskell - because it focused on important stuff and getting job done, not theory that looks only nice on paper, but doesn't match how hardware (and generally the world) operates. Real stuff is mutable. Not being able to mutate stuff in Haskell directly is a productivity killer. Many of the "abstractions" you can build in Haskell exist solely to workaround this limitation.
Exposure has nothing to do with this. Rust is new and Haskell is since forever, yet Rust already far surpassed Haskell in terms of adoption.
Template Haskell is not standard Haskell, it is an extension. But even with it, Haskell type system can't reason about lifetimes of objects. It doesn't give any guarantees about object destruction nor even object construction, due to laziness. Hence, you can't prove anything about resource usage of a Haskell program. Which makes it usable only for cases where you don't care about resources and where the program doesn't interact with external systems.
Well Haskell's prelude is purposefully small and extended by a variety of extensions in the GHC. Prelude + libs + extensions effectively make what we call Haskell today.
Just like with Elixir and many other high level languages I don't think it's meant for building low level systems where you're heavily constrained by resources.
But why wouldn't it be able to interact with external systems? I'm not having any problems building an API that interacts with a database, caching layer etc.
Now, not everybody actually need great performance, so some distance between hardware and abstraction is ok, but the amount depends on the use case.