okok

the Trampoline thing, right?

it’s just an example so don’t get hang up in the info displayed but it highlights what we can do for each of the arrow libs and patterns people frequently use in FP with meta

It's like having @raulraja whispering in your ear while you're programming

a couple of hacktoberfest tickets! https://github.com/arrow-kt/arrow/issues/1735 https://github.com/arrow-kt/arrow/issues/1732

We have plans for The Book of Arrow in 2020

This will be a type checked open source book the community can maintain and contribute to and available online most likely at the end of 2020

It will be bootstrapped by the 47 Degrees team and updated as the arrow journey progresses serving as the core in depth philosophical, technical and with a comic companion alongside each chapter in the ambience of a post apocalyptic wasteland where their last survivors will help change the world with principled programming

Lots of great things to look ahead for Arrow and FP in Kotlin in 2020

Ok, now a concrete question. I see that the

Try

is deprecated and we are pointed to

Either

. So how should I use

Either

in the following case where I have a code calling 3rd party library which can throw runtime exceptions (I don’t care which one, just if it failed and if not I want the result) :

Try {
   callLibraryCodeWhichCanThrowRuntimeExceptions()
}

How to idiomatically construct

Either

for such cases?

I would personally use IO for that, as it will defer the execution of that block until a point you want

Hello everyone. I saw this issue on github: https://github.com/arrow-kt/arrow/issues/1007 I wonder is arrow planned to be multiplatform compatible?

yes, definitely

we’re working on unblocking kapt, which was the biggest obstacle

it’ll be gone hopefully by end of the year

then we’ll do a rewrite to support MPP and the plugins

and the core should be js-compatible

cannot promise IO will tho

we’ll see

In response to other communities that are wondering how FP land is going in Kotlin: https://twitter.com/raulraja/status/1188023132554190849?s=19

Arrow and FP in Kotlin is one of the few places where you don't need to sacrifice imperative syntax to get pure FP and that is gonna be more notorious as we eliminate the need for some wrappers. Folks on other communities only see and think of the FP wrapped style as in Haskell or Scala but we can go further. We can make it easier for all Java and other folks that are already familiar with imperative syntax for them to also be able to write pure typed FP programs.

When Kotlin provides suspension or nullable types it immediately activates automatic Applicative and Monad syntax for IO and Option in the Lang and we can take that further with Union types and support for arbitrary product/coproduct at the compiler level to project what we'd do with Either in the environment.

alright, so... Does Arrow-kt make parser code cheaper? cleaner? simpler? faster? I would love to see something that's actually parsing a mini dsl as arrow expressions.

I am not too familiar with helios, but parser dsl's a la haskell (attoparsec, binary, trifecta) should be posible to build. They just don't exists yet afaik. Also the dsl will be just a little bit uglier due to typeclasses in kotlin, but with the plugin and implicit typeclass resolution coming up that should fix itself.

and haskell arguably has the best parsing libs there is^^

Hey team, What are some use cases of

Day

? https://github.com/arrow-kt/arrow/blob/master/modules/ui/arrow-ui-data/src/main/kotlin/arrow/ui/Day.kt