IMO, it's partly the ecosystem. There's regular Haskell, Haskell Platform, Cabal, Stack. It ends up being an alphabet soup of possibilities, and it's not clear what is depending on what.
And then there's monads, which are stumbling blocks.
State is allegedly the root of all evil. But I think the argument needs to be more nuanced than that: yes, state is difficult to reason about globally, but it's usually not so bad locally in small functions.
I think that this is what Rust gets wrong. It goes down the "state is evil" road, but there's really not that much wrong with the judicious use of mutated values.
If you really want to avoid mutability, then you're really going to need monads, something which seems a bad fit for Rust (based on what I see in Hackers News).
At the end of the day: fuggit, just use C++. It's fast, you can point in references to vars, and if you don't want them mutated, just make them const. That's the conclusion I drew a few years ago.
As Alan Kay might put it, most new languages are in the "pink plane": they're incremental improvements (sometimes a step back) on old ideas, and sometimes just inferior rehashes of them. None of them are what he calls "blue plane": revolutionary new ideas.
Kay seems to admire Erlang, though. What it brings to the table is the notion that a program can crash, and recover from it. That might be a "blue plane" idea.
I also assume he thinks Scratch is a blue plane idea; even though strictly speaking graphical languages are not new.
When I saw Ada couple of weeks ago, I noticed that it had the notion of tasks as a language primitive. I wonder if he'd consider that sufficiently blue plane.
I think your view of Rust is quite off. How is Rust view "state is evil"? At its core, Rust is very imperative and procedural.
Global reasoning about state is hard, hence the assistance from borrow checker. Locally mutating local state in small function? Put a reference to vars, if you want them to be mutated, just make them mut. It's also as fast.
In a way, Rust does better job of localize/encapsulate mutation than functional/monad world.
Waning is the natural course for any language. It takes a Miracle to avoid that fate. COBOL, FORTRAN, C, C++, Java, Javascript (and maybe Python?) each got a Miracle. Other languages didn't. Go and/or Rust might get one, but odds don't favor it.
Miracles are not awarded on merit, so when a language that got one is usable, it's like another miracle.
IMO, it's partly the ecosystem. There's regular Haskell, Haskell Platform, Cabal, Stack. It ends up being an alphabet soup of possibilities, and it's not clear what is depending on what.
And then there's monads, which are stumbling blocks.
State is allegedly the root of all evil. But I think the argument needs to be more nuanced than that: yes, state is difficult to reason about globally, but it's usually not so bad locally in small functions.
I think that this is what Rust gets wrong. It goes down the "state is evil" road, but there's really not that much wrong with the judicious use of mutated values.
If you really want to avoid mutability, then you're really going to need monads, something which seems a bad fit for Rust (based on what I see in Hackers News).
At the end of the day: fuggit, just use C++. It's fast, you can point in references to vars, and if you don't want them mutated, just make them const. That's the conclusion I drew a few years ago.
As Alan Kay might put it, most new languages are in the "pink plane": they're incremental improvements (sometimes a step back) on old ideas, and sometimes just inferior rehashes of them. None of them are what he calls "blue plane": revolutionary new ideas.
Kay seems to admire Erlang, though. What it brings to the table is the notion that a program can crash, and recover from it. That might be a "blue plane" idea.
I also assume he thinks Scratch is a blue plane idea; even though strictly speaking graphical languages are not new.
When I saw Ada couple of weeks ago, I noticed that it had the notion of tasks as a language primitive. I wonder if he'd consider that sufficiently blue plane.