> also many people are not familiar with nix and brew does all i need
it's a good reason to learn Nix then: it will completely replace your brew and offer an ultimate build tool suitable for any software stack moving forward. And you'll get cross-platform and static Haskell builds.
> But you want to focus on one end of the spectrum?
Have you actually checked the contents of the channels? Despite the naming, they do provide a full spectrum. You won't see the Mayfair-Knighstbridge side of things though, as these are irrelevant outliers when it comes to the country as a whole.
Don't trust BBC, they are the state propaganda machine. Draw your own conclusions, there's plenty of UK-based channels that provide the current footage from towns and cities around the country.
Generic over whatever you decide to compose out of smaller parts into a full algorithm that doesn't produce transient buffered results. Transducers is a dead end of abstractions, they aren't applicable anywhere but folding, lazy runtime gets you covered for free regardless of your choice of the exact source of either a foldable `Stream f e a`, or a generator of values on demand, or even a data constructor.
> doesn't address the actual transducer claim, which is: one value, applied to fundamentally different consumers (a channel, a fold, a stream, a transient collection) without recompilation or re-specialization.
the transducer claim is that there's no way to track effects, period. Hey, you've found a new abstraction that doesn't care about things, my congratulations, you're now on par with Python itertools!
> In Haskell, the closest analogs are conduit/pipes/streaming - each a library, each with its own type, each requiring adapters between them.
Do you understand why it's the case? It's because transducers are useless and people actually care about further optimisations and experimentation. To be on par with Clojure it would be enough to have a single `Stream m e a` that everyone would silently buy into. But no one opts for it, because people actually care about their local optimisations that go beyond what you think transducers give you. If you don't care about those, pick any generic enough interface and glue it with whatever you want in a single place for the entirey of your ecosystem. Had `Streamly` been part of `base`, you'd get exactly that property that you claim isn't a thing. Then maybe add `streamly` into your dependency list and start using it pervasively everywhere where iteration happens. You'll be on par with Clojure, but without the silly notion of transducers as a thing of its own (but it's not, it's only for foldings that don't care about side-effects).
> I said "Clojurians engage with diverse ideas pragmatically".
then you said nothing and contributed nothing to your points, as everybody else "engage with diverse ideas pragmatically". It also so happened that engaging allows for rejection of inferior ideas, which is what transducers are. I can compose around any Python iterable the same way you claim is important to transducers, but do you know what I lose if I engage with the pragmatic Python and Clojure? I lose precision and further optimizations.
> You seem to be operating on a single axiom
How about you abstain from drawing wrong conclusions and actually focus on being precise
> Spec generators are derived from predicates, not types
What do predicates operate on? QuickCheck builds bounded ints within their `minBound` and `maxBound` of the type, as the basis of Int spec deriving. There's no difference and no inversion of intent if your strategy for your newtype actually produces a spec deriving from 1-120 range. If you say there's a thing called Age, and it being a subset of Int or Nat ranges, you do define the Age and its bounds as part of your spec, and there's zero inversion to what clojure spec does. I'm beginning to suspect that I'm conversing with a prompt output.
> Okay, please, give me Haskell code that takes one composed transformation and applies it, unchanged, to a vector, a lazy seq, a channel, and a pure fold. Not 'here is pipes, here is conduit, here is streaming, here is foldl library' - one piece of code, four consumers. That's the thing you have dodged four times in the other thread.
Certainly, I'll do that as soon as you provide me with the example of a transducer tracking effects separately from pure evaluations. We want to be on the same page, don't we? I want to compose my effects without ambiguity, so hurry up.
> Clojure didn't ignore static types or the pure/effectful distinction - it made a deliberate decision to optimize for different values.
lol, it actually ignored it, but you're too perky to simply admit that as if your future depends on it.
> Every type system, schema library, and validation tool in every language is in some sense "patching" the lack of built-in guarantees.
> Spec isn't even so much about patching - it's about runtime generative testing, instrumentation, and data specification in a dynamic context where static types would be the wrong tool anyway.
it's amazing what people can claim when they don't have to prove it. But I wonder, how exactly does your runtime generative tests are different from statically derived strategies that I get via QuickCheck or Validity?
> And they do it with the focus on pragmatism
"pragmatism" is defined in terms of values that one desires to practice. I am in no position to argue that your and their desires don't exist, but please don't claim that their preferences of transducers and schemas are somehow more pragmatic just because they ignored types and effectful/pure evaluation distinction in their language philosophy.
> so you're saying "had it existed, you'd get the same thing", you're describing a different language.
that's not what I'm saying. I'm saying that Haskell doesn't have it because it's a useless and shallow abstraction to have, that also hampers the ability to apply advanced optimisation laws down the compilation pipeline.
I will just repost the part that you conveniently ignored in your reply and pretended that it didn't exist:
Let that sink in: it's not the transducer that's useful, it the differentiation between pure and side-effectful evaluations that allow your compiler to perform even better optimisations with out-of-order evaluations of pure stuff, as well as eliminating parts of inner steps within the composed step function, as opposed to focusing just on the reducing step-function during the composition. It's not a useful abstraction to have if you care about better precision and advanced optimisations coming from the ability to distinguish pure stuff from non-pure stuff.
My argument holds: you get the same composability with lazy functions for free, you don't need to apply rewrite rules to be on the same level of reusability. Haskell grants you that for free, but for some reason you chime in and claim that's not the case and the only proof you've provided had to do with missing interfaces that can be solved by a library implementation. There's no restriction in the type system, nor runtime, to have it. But people don't need it because it's a useless abstraction that doesn't improve the baseline of what Haskell has to offer both in terms of composability of your foldings and further optimisations that take iteration purity into account.
> You've drifted from
I didn't drift from anything, I told you that you ignored a library-based solution in a sneaky attempt to move the goalpost from "you need rewrite rules in many places" to "there's no interface generic enough to accomodate effectful and non-effectful steps together without a library implementation".
> Haskell's laziness isn't a superior version of transducers
It absolutely is a superior solution to the same problem of algorithm optimisation and composability. It's more generic, it applies to anamorphisms and hylomorphisms in the same way as it does to foldings, and it doesn't introduce a special terminology to a single building block that doesn't exist outside foldings anyways.
> but please stop spreading confusion and misinformation
that's a bold statement coming from someone that claims that call-by-need semantics in Haskell is a negative aspect of the language according to other people (who probably didn't mean it in the first place, but you wouldn't dare to verify).
Why do you eliminate a library-based solution from the equation if it can actually prove the point that there's no difference in intent as long as my runtime is already lazy by default?
> It is not. Take a transducer like `(comp (filter odd?) (map inc) (take 5))`. You can apply this to a vector, a lazy seq, a core.async channel, or a custom step function you wrote five minutes ago. In Haskell, fusing over a list is one thing. Applying that same composed transformation to a conduit, a streaming pipeline, an io-streams source, and a pure fold requires different code or different typeclass machinery for each.
You can do that only because Clojure doesn't care whether the underlying iterable is to be processed by a side-effectful evaluation. That doesn't negate the fact that the underlying evaluation has a useless notion of "transducer". I said "fuse" in my previous comment to demonstrate that further comptime optimisations are possible that eliminate some transient steps altogether. If you don't need that you can just rely on generic lazy composition of functions that you define once over type classes' constraints.
`IsList` + `OverloadedLists` already exist. Had Haskell had a single type class for all iterable implicitly side-effectful data, you would have got the same singly-written algorithm without a single notion of a transducer. Let that sink in: it's not the transducer that's useful, it the differentiation between pure and side-effectful evaluations that allow your compiler to perform even better optimisations with out-of-order evaluations of pure stuff, as well as eliminating parts of inner steps within the composed step function, as opposed to focusing just on the reducing step-function during the composition. It's not a useful abstraction to have if you care about better precision and advanced optimisations coming from the ability to distinguish pure stuff from non-pure stuff.
Haskell aside, if your goal is to just compose reusable algorithms, a call-by-need runtime + currying + pointfree notation get you covered, you don't need a notion of transducers that exist on their own (outside of the notion of foldable interfaces) to be able to claim exactly the same benefits.
> Two Haskell Simons - Marlow, and Jones, and also Edward Kmett have all written and spoken about the difficulty of reasoning about space behavior in lazy Haskell.
There's a difference between what the people said in the past, and the things the crowd claims the people meant about laziness and space leaks. We can go over individual statements and see if they hold the same "negative" meaning that you say is there.
> Haskell's laziness gives you fusion-like memory behavior on lists for free.
Haskell laziness & fusion isn't limited to lists, you can fuse any lawful composition of functions applied over data with the required lawful instances used for the said composition. There's no difference to what transducers are designed for.
> But transducers solve a broader problem - portable, composable, context-independent transformations over arbitrary reducing processes - and that you don't get for free in Haskell either.
Transducers don't solve a broader problem, it's the same problem of reducing complexities of your algorithims by eliminating transient data representations. If you think otherwise, I invite you to provide a practical example of the broader scope, especially the part about "context-independent transformations" that would be different to what Haskell provides you without that separate notion.
> and negative (space leaks, reasoning difficulty about resource usage).
which is mostly FUD spread by internet crowd who don't know the basics of call-by-need semantics, such as the places you don't bind your intermediate evaluations at, and what language constructs implicitly force evaluations for you.
> It goes beyond a foldable, can be applied to streams.
> Clojure had foldables, called reducers, this was generalized further when core.async came along - transducers can be attached to core async channels and also used in places where reducers were used.
Ok, you mean there's a distinction between foldables and the effectful and/or infinite streams, so there's natural divide between them in terms of interfaces such as (for instance) `Foldable f` and `Stream f e` where `e` is the effect context. It's a fair distinction, however, I guess my overall point is that they all have applicability within the same kind of folding algorithms that don't need a separate notion of "a composing object that's called a transducer" if you hop your Clojure practice onto Haskell runtime where transformations are lazy by default.
You get this for free in Haskell, and you also save on not having to remember useless terminology for something that has no application on their own outside Foldables anyways.
If you really cared about that, you wouldn't have picked Rust. Nim or Haskell are terser languages.
> Every language we’ve built defaults to sequential execution with parallelism bolted on.
False and misleading statement. Array languages have been around for a long time, but you didn't care to learn them.
> Formal verifiability. Move beyond type checking to compile-time proofs.
Good luck with your tokens budget for proof providing. LLMs won't solve that for you. If you believe that proofs are as simple as matching API calling inerfaces you're wrong.
> Declared effects. Every function explicitly states what it reads, writes, and depends on, machine-enforced.
Good functions are pure functions that have no effects. Good design tries to minimize the number of effects needed and maximize the footprint of pure functions mapped over inputs and outputs. If you insist that every function needs an explicit effect annotation, you don't know the topic and you haven't worked with effect systems much.
Just juggling with balls in the air gets boring very quickly, and the added numbers don't make it much different. Learning statics and flows from contact juggling, but performing them with standard juggling balls is so much more fun. And then you discover statics with hoops: https://www.youtube.com/watch?v=PF6UuPsw2i4
He argued against putting things in a spectrum in many instances where that would be wrong, including the case under the question. What's your argument against that idea? LLM'ed too much lately?
yes:
https://nixos.org/download/
> also many people are not familiar with nix and brew does all i need
it's a good reason to learn Nix then: it will completely replace your brew and offer an ultimate build tool suitable for any software stack moving forward. And you'll get cross-platform and static Haskell builds.