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Monads and GATs in Nightly Rust

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Re: Monads and GATs in Nightly Rust

#171

Post by whateveracct »

lambda_obrien wrote: post #159
whateveracct wrote: post #145

Earlier quoted context omitted.

Yeah you can do that. I'm actually working on a little library to do just that (control memory layout) although it's more focused on 0-copy FFI w/hsc2hs You can also have the RTS manage the memory itself, but have complete access to a pointer to raw memory. That doesn't work if you have pointers in the raw memory ofc, but it is a nice option if that's not the case.

If you don't mind, can you send me your repos if it's public work? I'm interested in 0-copy stuff, too, the database I'm doing can benefit from 0-copy (again, a small part of the codebase but a big part of the technical challenge), and I'm seeing that linear types help a lot with that kind of thing from the reading I've done lately. I'm mostly a tinkerer and like to see what's the newest cool stuff people are making.…

Will do!

Re: Monads and GATs in Nightly Rust

#172

Post by mbrodersen »

Thaxll wrote: post #56
bluGill wrote: post #44

Earlier quoted context omitted.

Yes, more features make a better language. I need those features to abstract my software so I can wrap my mind around all 15 million lines of code I have to deal with (that is both too many for one human to understand, and yet I know many will respond that they work on much larger system!). We don't need new languages without features: it has already been proven that you only need exactly one feature in your programm…

"Yes, more features make a better language" At the pace of what Rust is adding feature, it's the next C++ in the next 5-10years.

So what you mean is that Rust might end up being as successful as C++? One of the most successful programming languages ever created?

Re: Monads and GATs in Nightly Rust

#173

Post by sorenbs »

uDontKnowMe wrote: post #135
ebruchez wrote: post #108

Earlier quoted context omitted.

> I saw Scala taken over and destroyed by the FP fanatics I suspect that the above reflects a very personal experience rather than something general. I have been using Scala for 10 years and never used monad transformers. I find Scala code usually easy to write and to read. At this point I wouldn't trade it for any other language. From where I stand, Scala was neither "taken over", nor "destroyed by FP fanatics". It…

I have worked in multiple Scala shops and contributed at the highest levels to the Scala ecosystem and my experiences confirm that this rotten attitude is very real and increasingly the norm, as everyone but the fanatical FP-ers have long-since moved on to other more professional/productive circles. With the exception of shops using Scala exclusively for Spark, someone entering the ecosystem can expect to be constant…

I'm not sure why Prisma is called out here. But posts like this bubble up in our Slack, so I thought I should respond...

Prismas query engine is a complex piece of code and receives very little outside contributions. Moreover, Prisma only has bindings for JS/TypeScript and Go at the moment, so there is no way to consume Prisma from Scala. As a result, very few Scala developers know about Prisma.

We enjoyed Scala as a language, and the massive JVM ecosystem is a huge benefit. That said, we were forced to rewrite the query engine in Rust as we had a need for a more modular architecture enabling us to embed parts in JS and Go libraries. We looked at the Scala Native and Graal projects (spent 6 months building a prototype), but neither delivered a sufficiently low memory footprint. The Prisma2 rewrite to rust is a much more stable product, and we love the Rust language.

All the best to both the Scala and Rust ecosystems. Hugs.

Re: Monads and GATs in Nightly Rust

#174

Post by alquemist »

tome wrote: post #166
pdimitar wrote: post #165

Earlier quoted context omitted.

Definitely, but I'd imagine this is being frowned upon because the realistic (and non-fanatic) folks who use Haskell, use it mostly for these advanced features, I'd imagine. Could be wrong.

There are quite a number of realistic folks who want to use Haskell because of the simplicity of its basic feature set. See, for example * https://www.simplehaskell.org/ * https://www.snoyman.com/blog/2019/11/boring-haskell-manifest...

Can not resist. The tension between 'basic feature set' and an admittedly superficial reading of the docs is very funny. The manifesto links to https://github.com/commercialhaskell/rio#readme and urges us to use the rio library to get started. Upon opening the rio link and scanning for a list of the 'basic feature set', I stumble upon the first block of quoted code. After removing 39 eoln characters in respect for the HN audience, it reads:

"Our recommended [language extensions] defaults are: AutoDeriveTypeable BangPatterns BinaryLiterals ConstraintKinds DataKinds DefaultSignatures DeriveDataTypeable DeriveFoldable DeriveFunctor DeriveGeneric DeriveTraversable DoAndIfThenElse EmptyDataDecls ExistentialQuantification FlexibleContexts FlexibleInstances FunctionalDependencies GADTs GeneralizedNewtypeDeriving InstanceSigs KindSignatures LambdaCase MonadFailDesugaring MultiParamTypeClasses MultiWayIf NamedFieldPuns NoImplicitPrelude OverloadedStrings PartialTypeSignatures PatternGuards PolyKinds RankNTypes RecordWildCards ScopedTypeVariables StandaloneDeriving TupleSections TypeFamilies TypeSynonymInstances ViewPatterns"

39 language extensions just to get started. This screams 'incredibly complicated', even if perhaps reality is rather more mundane. Consider the 40th language extension: GradualTyping, so perhaps those that would rather write code about data than about types using a half baked and evolving type language (which taken to its logical conclusion will have to become a full fledged theorem prover in the Coq / Idris / Agda / Lean lineage anyways) could get their jobs done.

Wish you guys all the best!

Re: Monads and GATs in Nightly Rust

#175

Post by monoideism »

monoideism wrote: post #24
dragonelite wrote: post #14

How does one get familiar with these kind meta programming concepts. Is there some kind bible or series one can read to get up to speed?

Many Haskell and functional Scala books will give you a good understanding of type-driven development, but I'd recommend "Functional Scala" by Chisano/Bjarnson (and do the exercises). Alternately, "Learn You a Haskell" will provide a decent base. Either of these will give you the base needed to explore higher-level concepts that can easily be used in Haskell, Scala, Purescript, OCaml, a few statically-typed functiona…

I meant to write, "a few other statically typed functional languages".

Re: Monads and GATs in Nightly Rust

#176

Post by tome »

alquemist wrote: post #174
tome wrote: post #166

Earlier quoted context omitted.

There are quite a number of realistic folks who want to use Haskell because of the simplicity of its basic feature set. See, for example * https://www.simplehaskell.org/ * https://www.snoyman.com/blog/2019/11/boring-haskell-manifest...

Can not resist. The tension between 'basic feature set' and an admittedly superficial reading of the docs is very funny. The manifesto links to https://github.com/commercialhaskell/rio#readme and urges us to use the rio library to get started. Upon opening the rio link and scanning for a list of the 'basic feature set', I stumble upon the first block of quoted code. After removing 39 eoln characters in respect for th…

This is a common response to Haskell language extensions. It comes from a misunderstanding of what a language extension is. A Haskell language extension is not "something that radically changes the language"; it is "a small, self-contained, well-tested piece of functionality that for whatever reason wasn't part of the Haskell 2010 standard". In any other language a "language extension" would just be "a feature of the language".
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