Http4s
cats-effect
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Http4s | cats-effect | |
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24 | 34 | |
2,505 | 1,948 | |
0.4% | 1.4% | |
9.8 | 9.7 | |
1 day ago | 7 days ago | |
Scala | Scala | |
Apache License 2.0 | Apache License 2.0 |
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
Http4s
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How to get started?
http4s is a Typelevel project, and therefore falls into the "program in Scala as if it were Haskell" category. Many people find this off-putting, but honestly, I think with the resources listed above, this is the option at the best intersection of "mature" and "well-documented" available in Scala. The reason it's off-putting to many people is that Haskell-style pure FP isn't mainstream, so it isn't so much a matter of learning a new technology as it is a matter of learning a new paradigm, which necessarily means surfacing and unlearning things you already know, and perhaps confronting the uncomfortable feeling that things you thought were "fundamental," "have to be that way," aren't, and don't. I personally found this process liberating. But not everyone does.
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Server Stack Options for Scala
If you want a mature REST API library, I recommend http4s. Be aware, though, that it’s based on purely-functional programming with Cats, cats-effect, and fs2, so if you’re not familiar with them or aren’t prepared to commit to the paradigm, the learning curve may be daunting, seem pointless, or both.
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Sequential application of a constructor?
See also cats-effect and fs2. cats-effect gives you your IO Monad (and IOApp to run it with on supported platforms). fs2 is the ecosystem’s streaming library, which is much more pervasive in functional Scala than in Haskell. For example, http4s and Doobie are both based on fs2.
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Grasping the concepts and getting them down to earth
Most important/known: * https://http4s.org/ - an HTTP client/server * https://github.com/typelevel/fs2 - streaming * https://github.com/tpolecat/doobie - JDBC
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Relative popularity of programming languages on Hacker News
Scala devs are too busy wondering about free monads and F[Request[F] => Response[F]]. I am very pleased by http4s, Doobie, ScalaJS, and the whole ecosystem, really: https://http4s.org
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http4s as a replacement for akka-http?
In reality, your performance issues will not be http4s, but something else. That being said, there are improvements that http4s can and is making, and I'm quite excited about the future 1.0 release, which has some important and fundamental performance improvements already, like a a 125% performance improvement on the plaintext benchmark from https://github.com/http4s/http4s/pull/6091 - and finally, yes, akka-http does have very good performance, but you can also get good performance out of http4s.
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Is Scala a good choice for a data intensive web backend?
http4s for REST services.
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Scala became Typelevel/Zio only ecosystem?
This is a long list of misunderstandings I don’t have the patience to unpack. Instead, let me refer you to the links in my top comment in the thread, then suggest you learn at least http4s, a purely-functional web service library that’s been used in production for a decade or so now.
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Pleasant to use Scala libraries
The most popular nowadays are - I guess - akka-http and http4s. You can also use Play if you don't want to start from scratch but prefer a framework-based approach.
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Why do all frameworks use OOP? (php)
There are functional frameworks: https://http4s.org/
cats-effect
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A question about Http4s new major version
Those benchmarks are using a snapshot version of cats-effect. I don't know where that one comes from, but previously they were using a snapshot from https://github.com/typelevel/cats-effect/pull/3332 which had some issues (3.5-6581dc4, 70% performance degradation), which have since been resolved (see that PR for more info and comparative benchmarks).
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The Great Concurrency Smackdown: ZIO versus JDK by John A. De Goes
Recently, CE3 has had similar issues reported across multiple repositories, almost an epidemic of reports!
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40x Faster! We rewrote our project with Rust!
The one advantage Rust has over Scala is that it detects data races at compile time, and that's a big time saver if you use low level thread synchronization. However, if you write pure FP code with ZIO or Cats Effect that's basically a non-issue anyway.
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Sequential application of a constructor?
See also cats-effect and fs2. cats-effect gives you your IO Monad (and IOApp to run it with on supported platforms). fs2 is the ecosystem’s streaming library, which is much more pervasive in functional Scala than in Haskell. For example, http4s and Doobie are both based on fs2.
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Should I Move From PHP to Node/Express?
On the contrary, switching to the functional mindset, with something like Typelevel Scala3 and respective cats and cats-effect fs2 frameworks, helps to rethink a lot of designs and development approaches.
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Next Steps for Rust in the Kernel
I think "better Haskell on JVM" (in contrast to "worse Haskell") is a good identity for Scala to have. (Please note that this is an intentional hyperbole.)
Of course, there are areas where Haskell is stronger than Scala (hint: modularity, crucial for good Software Engineering, is not one of them). And Scala has its own way of doing things, so just imitating Haskell won't work well.
Examples of this "better Haskell" are https://typelevel.org/cats-effect/ and https://zio.dev/ .
All together, Scala may be a better choice for you if you want to do Pure Functional Programming. And is definitely less risky (runs on JVM, Java libraries interop, IntelliJ, easy debugging, etc...).
None of the other languages you mentioned are viable in this sense (if also you want a powerful type system, which rules out Clojure).
I agree that Rust's identity is pretty clear: a modern language for use cases where only C or C++ could have been used before.
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Java 19 Is Out
I would use Scala. I like FP and Scala comes with some awesome libraries for concurrent/async programming like Cats Effect or ZIO. Good choice for creating modern style micro-services to be run in the cloud (or even macro-services, Scala has a powerful module system, so it's made to handle large codebases).
https://typelevel.org/cats-effect/
The language, the community and customs are great. You don't have to worry about nulls, things are immutable by default, domain modelling with ADTs and patter matching is pure joy.
The tooling available is from good to great and Scala is big enough that there are good libraries for typical if not vast majority of stuff and Java libs as a reliable fallback.
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Typelevel Native
What took my interest is this (for both JVM and future multithreaded Scala native): https://github.com/typelevel/cats-effect/discussions/3070 Having the same threads poll available IO events and execute callbacks should improve performance greatly
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Scala isn't fun anymore
The author is the creator of Monix and implemented the first version of cats-effect. He knows what he is doing.
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Question about some advanced types
You want Kernmantle, which quite honestly shouldn't be hard to implement around Cats and cats-effect. In particular, although Kernmantle doesn't require the use of the Arrow typeclass, there happen to be Arrow (actually ArrowChoice) instances for both Function1 from the standard library and Kleisli from Cats itself, given a Monad instance for the Kleilsi's F[_] type parameter. In other words, we should be able to port Kernmantle from Haskell to Scala (with the Typelevel ecosystem) and instantly be able to use pretty much anything else from the Typelevel ecosystem, or wrapped with it, in our workflow graphs. Pure functions, monadic functions, applicative functions, GADTs with hand-written interpreters, any of it. I think this would be eminently worth doing.
What are some alternatives?
Akka HTTP - The Streaming-first HTTP server/module of Akka
ZIO - ZIO — A type-safe, composable library for async and concurrent programming in Scala
sttp - The Scala HTTP client you always wanted!
FS2 - Compositional, streaming I/O library for Scala
fs2-grpc - gRPC implementation for FS2/cats-effect
Finch.io - Scala combinator library for building Finagle HTTP services
doobie-quill - Integration between Doobie and Quill libraries
zio-http - A next-generation Scala framework for building scalable, correct, and efficient HTTP clients and servers
Kategory - Λrrow - Functional companion to Kotlin's Standard Library
Spray - A suite of scala libraries for building and consuming RESTful web services on top of Akka: lightweight, asynchronous, non-blocking, actor-based, testable
Slick - Slick (Scala Language Integrated Connection Kit) is a modern database query and access library for Scala