Async is equivalent to the io monad. It is in itself a monad, I know, but I’m saying it’s just like the io monad. It pollutes everything it touches. It’s literally only effective when paired with IO. So it’s actually in many ways identical.
And that’s a good thing.
In attempting to avoid the pollution u end up implementing the imperative shell/functional core pattern.
Most programmers don’t know that pattern. But for those in the know, the pollution is a good thing.
If you programmed in Haskell you know what’s up. The way you avoid the io monad from polluting everything is part of what makes the program so modular. Async does the same thing. Literally.
await b(await a())
The above is roughly equivalent to this in haskell:
a >>= b
How do you avoid pollution? The answer to this question makes your program better.
Haskell has significantly more powerful abstraction capabilities than your average async/await language though, making coloring less of a problem.
Also in Haskell you can only perform IO (aside from unsafe IO I guess) inside the IO monad, potentially making the abstraction worthwhile, this is not the case in many other languages.
> The above is roughly equivalent to this in haskell:
It's not equivalent.
> How do you avoid pollution?
Haskell has <$> and the infrastructure of HKTs to stop this infectious propagation of IO, other languages do not, and their async/await colors do not isolate side-effectful actions from the rest pure parts of your codebase.
I said roughly equivalent. Async functions pollute and represent io in the same way the io monad does.
The io monad does not isolate io from your pure code. It’s infectious just like an async function.
It’s the abstractions and ways to stop the infection that makes the code pure. You don’t even need hkts to do this. Most languages don’t have a type representing this infection. The infection propagates everywhere without anyone realizing it. The IO monad explicitly tells the developer that the infection is occurring.
I’m saying that async functions do the same thing as the io monad.
The <$> operator in Haskell is just sugar for patterns to stop the pollution from occurring. You can implement it in typescript too. It just won’t be as general as that operator is defined across functors. In typescript you would define a function across only promises.
> I’m saying that async functions do the same thing as the io monad.
> The <$> operator in Haskell is just sugar for patterns to stop the pollution from occurring.
No they don't. Async functions aren't IO actions in Haskell terms, and for the latter argument of <$>, you need referential transparency (via laziness) too, otherwise your attempt at "sugaring" your async functions will break at the first binding expression in a local scope for future processing elsewhere:
...
let arg = processData <$> ioAction
in ...
Do you want to wrap-and-call-later all of these cases into lambdas by hand? :) Show me an example of that being done in a type-safe way in typescript, and I'll point you at the layers that will break composition at the next binding.
If You want to redefine the meaning of roughly equivalent then that’s your prerogative. There’s an isomorphism I’m referring to here and if you fail to see it that’s not my problem.
As for the rest of your argument, the point is to not use async functions locally in the context of pure logic. The pattern is imperative shell, functional core.
Adding a property-changing prefix to "equivalent" makes it non-equivalent, I thought you would understand it if you were using the word "isomorphism".
> the point is to not use async functions locally in the context of pure logic. The pattern is imperative shell, functional core.
The point is that IO actions aren't `async defs`, because async defs don't have two important properties to hold eqivalence to IO actions in Haskell. I'm not sure why you're trying to cherry pick arguments to see your argument fit into the slots that don't accept coloring keywords where they don't belong to: seamless composition.
You’re just playing pedantic games. By roughly equivalent I mean isomorphic. Do you not get it? Isomorphism isn’t equivalency. Sure thanks for pointing the obvious out. Why don’t we get with the program rather than state pedantic details?
IO actions aren’t equivalent to async defs. I never said that. I said roughly equivalent which means isomorphic.
I’m not sure why you’re trying to say I’m cherry picking my argument when I am the one dictating the point here. I made the first statement and you responded to it and you started out your previous response by trying to turn the conversation to your point.
Bro I made the point. I’m not changing the point. You need to not change the topic. In the very beginning I said functional core imperative shell. That’s the point.
I guess the io monad doesn’t prevent people from writing shit code in Haskell. You’re weaving in and out of io constantly with almost everything polluted with IO. Pure functions are scattered randomly in a patchwork of compositions without delineation between purity and IO. You don’t see that there needs to be a layer between the two.
> I said roughly equivalent which means isomorphic.
"roughly equivalent" isn't the definition of isomorphic, and I hinted which properties a type system and the runtime have to support for that isomorphism to be manifested in a language implementation, which isn't there for all of the mainstream languages, unless you're willing to provide that conversion by hand.
> when I am the one dictating the point here. I made the first statement and you responded to it and you started out your previous response by trying to turn the conversation to your point.
You're simply wrong, that happens.
> In the very beginning I said functional core imperative shell. That’s the point.
That terminology only exists as a coping mechanism for those on the mainstream languages. In Haskell everything is functional composition, and `IO a` is neither exempt from it, nor is made into a special case. When you realise this I'll congratulate you on becoming less ignorant.
I’m not continuing this further. The thread has turned from discussion to conflict and we are both at fault. I’m ending it here and pray that dang doesn’t come along and flag the whole thing. Good day to you sir.
It’s eye opening if you get it. I realize this thread is childish and arrogant but that’s largely orthogonal to the epiphany you gain from grokking Haskell.
"X is just a monad" isn't a useful statement, because lots of types are monads (e.g. lists, hash maps, and nullable pointers).
An important difference between async/await and Haskell's `IO a` is that it's possible for asynchronous code to invoke sync code, and in some languages (such as Rust) vice-versa. So it acts more like a monad transformer, providing operations `IO a -> AsyncIO a` and `AsyncIO a -> IO a`.
The main challenge of async/await is that unskilled people who don't understand threads try to use async/await as a substitute, which leads to bizarre articles like "what color are your functions".
I said async functions can be treated as the IO monad. And I also said that I realize that promises are themselves monads but that wasn’t my point. The point was to use async functions as coloring in the same way Haskell does it with the IO monad.
And that’s a good thing.
In attempting to avoid the pollution u end up implementing the imperative shell/functional core pattern.
Most programmers don’t know that pattern. But for those in the know, the pollution is a good thing.
If you programmed in Haskell you know what’s up. The way you avoid the io monad from polluting everything is part of what makes the program so modular. Async does the same thing. Literally.
The above is roughly equivalent to this in haskell: How do you avoid pollution? The answer to this question makes your program better.