FYI, here is the issue with the discussion and analysis of the alternatives for the migration. frees-io/freestyle#539
We are preparing for our first meeting in NYC for the Freestyle Enthusiasts group. I have been compiling information to share with the group - the idea is to form some sort of study group exploring freestyle. Here is a link for what i have so far: https://docs.google.com/presentation/d/1ZNfGrNKoZmo9gLM4O43xdMKr6uD-ymQqINYg2C71AUM/edit?usp=sharing If anyone could suggest any improvements I would appreciate it
seems like a really good complement to the red book
@fommil - it is filling in some gaps - i have been reading the Milewski book https://github.com/hmemcpy/milewski-ctfp-pdf and this helps bring some of the concepts into the scala context
I'm banned there, for unexplained reasons
which was a lovely leaving gift, I have to say.
but I am now a Haskell developer at work
e.g. fommil/fpmortals#14
chapters can be translated in parallel
Sorry, this isn’t directly related to Freestyle but this seemed like a good room to find people who know about Cats Free Monads :) I was just reading Runar’s “Stackless Scala with Free monads” (http://days2012.scala-lang.org/sites/days2012/files/bjarnason_trampolines.pdf) and comparing to the cats free implementation. In section 4.3, he introduces a
flatMap method to reassociate binds to the right on construction and says that otherwise resume can cause a stack overflow. However, without this, resume still looks to be tail-recursive and I notice that the cats free implementation does not do this re-binding. Am I missing something?
@TimWSpence we are trying to start some online meetups to talk about things like this. https://www.meetup.com/New-York-FreeStyle-Enthusiasts/?_cookie-check=aQWQSqUK3G5i1rvQ
I extracted the todolib examples out into separate projects and created some Giter8 templates to make it easy for developers to use the example as a prototype for their own apps: https://jmenke.blogspot.com/2018/10/giter8-templates-for-freestylerpc-part-1.html
@raulraja OK i added: https://github.com/higherkindness/freestyle-rpc/compare/master...jmjava:patch-1
If the templates use Freestyle-RPC then they should be there
I don't know if it's possible but ideally Travis in Freestyle-RPC also builds project instances of those templates and compiles them to ensure that we don't break them as we evolve the library.
Feel free to mention me and @juanpedromoreno when you submit the PR and one of us will get to reviewing it.
I understand, I am setting up automated builds in gitlab right now. I think to be fully functional I need to automate a copy process from the examples in freestyle and freestyle-rpc into the g8 templates and then also refactor dependency versions into a separate file. I will let you know when that is working in gitlab - from there maybe it could be migrated to travis? I don't think g8 can do this dynamically - hopefully the copy task might not be that bad...even though its brute force
Hello. I have a really strange compilation error when using freestyle library. My code compiles fine with Intellij IDEA and I can run, debug the app within the IDE. But when building with sbt it shows compilation error for accessing companion object of a module. Below are the code that gets error:
import freestyle.tagless._
// top most module
@module
trait Application[F[_]] {
// some smaller modules
val appA: ApplicationA[F]
}
@module ApplicationA[F[_]] {
// service dependencies
val service: Service[F]
}
// service code and interpreters …
@tagless(true)
trait Service[F[_]] { … }
// create instance of the app
type Program[A] = …
val app: Application[Program] = Application[Program] // error
// the last line is reported in sbt as "not found: value Application”
// [error] val app: Application[Program] = Application[Program]
// [error] ^Does anyone see any issue similar to this?
Hi guys! I need some sample application to look how to use freestyle @free.
For example https://github.com/pauljamescleary/scala-pet-store shows Free monad and Tagless final usages
But I need sample which includes doobie and freestyle. Freestyle docs not useful or I don't have enough knowledge to use freestyle
I'm going to use freestyle on scala-pet-store like project
For example https://github.com/pauljamescleary/scala-pet-store shows Free monad and Tagless final usages
But I need sample which includes doobie and freestyle. Freestyle docs not useful or I don't have enough knowledge to use freestyle
I'm going to use freestyle on scala-pet-store like project
@ikr0m Good evening. If you are interested in using
For instance, we have an example of a Todo-app, where the handler is implemented with Doobie: https://github.com/frees-io/freestyle/blob/master/modules/examples/todolist-lib/src/main/scala/todo/persistence/runtime/TodoListRepositoryHandler.scala
freestyle, perhaps you may want to check some of the examples we have in the repository.For instance, we have an example of a Todo-app, where the handler is implemented with Doobie: https://github.com/frees-io/freestyle/blob/master/modules/examples/todolist-lib/src/main/scala/todo/persistence/runtime/TodoListRepositoryHandler.scala
The algebras for this example are written with the macro
@tagless(true), which generates both the "tagless" representation as well as a Free-algebra (Called the StackSafe). Naturally, the handler for the tagless is also a handler for the free one.
@diesalbla thanks! Examples, you provided, do not use
FS effect. But samples in http://frees.io/docs/core/algebras/ heavily use FS effect. Is there any reason it's not used in examples?
So, the FS is a generated type member of the "algebra" trait, which is used as an alias for the F[_] type parameter
We added it at the time as a bit of syntactic sugar, to hide the F[_] declaration:
@free trait Fili[F[_]] {
def kili: F[Int]
}
/////
@free trait Fili {
def kili: FS[Int]
}But it is not essential to use the macro.
I am curious: are you trying to learn about freestyle for learning the theory? Or is it something you would like to apply to your work ?
Thanks for clarification.
I'm learning functional programming (cats, doobie, http4s, fs2, ...). We want to use these technologies in our next projects.
Now I'm writing very similar project to https://github.com/pauljamescleary/scala-pet-store
It uses tagless-final.
I wrote my project in 2 versions: tagless-final and free monad versions.
Now I'm learning Freestyle and want to apply it to scala-pet-store like project. It will be 3rd version with freestyle
I'm learning functional programming (cats, doobie, http4s, fs2, ...). We want to use these technologies in our next projects.
Now I'm writing very similar project to https://github.com/pauljamescleary/scala-pet-store
It uses tagless-final.
I wrote my project in 2 versions: tagless-final and free monad versions.
Now I'm learning Freestyle and want to apply it to scala-pet-store like project. It will be 3rd version with freestyle
@ikr0m If you want to use the tagless style, we recommend you use
https://typelevel.org/cats-tagless/
cats-tagless: that library has some better support for that style, with a few interesting constructors.https://typelevel.org/cats-tagless/