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  • r

    raulraja

    03/09/2019, 1:19 PM
    it does bunch of stuff
  • r

    raulraja

    03/09/2019, 1:19 PM
    and we can also have CoGen
  • s

    simon.vergauwen

    03/09/2019, 1:20 PM
    We could also include HK boilerplate without relying on core, right?
  • r

    raulraja

    03/09/2019, 1:20 PM
    no because Kind is in core
  • s

    simon.vergauwen

    03/09/2019, 1:20 PM
    I mean manually adding it for 1 type is not so much overhead
  • s

    simon.vergauwen

    03/09/2019, 1:20 PM
    Oh right
  • s

    simon.vergauwen

    03/09/2019, 1:20 PM
    What about KindedJ?
  • s

    simon.vergauwen

    03/09/2019, 1:20 PM
    That'd be the same as wrapping?
  • r

    raulraja

    03/09/2019, 1:20 PM
    we can move kind out though to it's own module for 0.9.1 if that eases the pain in any way
  • s

    sam

    03/09/2019, 1:20 PM
    You're going a bit over my head I'm afraid. I'm not that skilled with FP (trying to get better). What do you need Gen to do? Just literally have a dependency on arrow-core? If so (we can) but why out of interest does it need to be in the kotlintest module. Or do you mean something else.
  • s

    simon.vergauwen

    03/09/2019, 1:20 PM
    Something we might consider
  • r

    raulraja

    03/09/2019, 1:21 PM
    @sam If you enable Gen as a @higherkind this allows Arrow to use Gen in a polymorphic fashion and abstract over what it contains
  • r

    raulraja

    03/09/2019, 1:21 PM
    This enables all the extensions functions in the Functor hierarchy
  • s

    sam

    03/09/2019, 1:21 PM
    so it's the annotation you need.
  • r

    raulraja

    03/09/2019, 1:21 PM
    and activates all the arrow DSLs over Gen and integration with the entire Arrow ecosystem
  • s

    sam

    03/09/2019, 1:21 PM
    If we add it, does it have any adverse effects on anyone who doesn't want to use Arrow?
  • r

    raulraja

    03/09/2019, 1:22 PM
    yes we need Gen to extend GenOf<A>
  • r

    raulraja

    03/09/2019, 1:22 PM
    which is achieved with annotation or some minimal boilerplate:
  • r

    raulraja

    03/09/2019, 1:22 PM
    For example:
  • r

    raulraja

    03/09/2019, 1:23 PM
    Copy code
    @higherkind data class ListK<A>(val list: List<A>): ListKOf<A>

// Generates the following code:
//
// class ForListK private constructor() { companion object {} }
// typealias ListKOf<A> = Kind<ForListK, A>
// fun ListKOf<A>.fix() = this as ListK<A>
  • r

    raulraja

    03/09/2019, 1:23 PM
    no need to have kapt if you just add the code but it depends on 
    Kind
    which is in arrow-core
  • p

    pakoito

    03/09/2019, 1:23 PM
    @sam no adverse effects, no extra buildtime, just a couple of extra functions and classes generated
  • s

    sam

    03/09/2019, 1:24 PM
    we already use arrow-core in kotlintest itself
  • s

    sam

    03/09/2019, 1:24 PM
    the assertions module is separate but I don't see any reason why it can't depend on it, it's probably quite small?
  • r

    raulraja

    03/09/2019, 1:24 PM
    yeah but not in the dep where Gen is declared, so wasn't sure if it made sense to you
  • r

    raulraja

    03/09/2019, 1:24 PM
    yeah arrow core is small
  • r

    raulraja

    03/09/2019, 1:24 PM
    and it's actually 
    arrow-core-data
  • r

    raulraja

    03/09/2019, 1:24 PM
    without the extensions or type classes
  • r

    raulraja

    03/09/2019, 1:24 PM
    just the basic Option, Either etc data types
  • s

    sam

    03/09/2019, 1:25 PM
    Well as I saying earlier, I want to use Show to generate better toStrings for failed assertions so we'll need Arrow anyway - which means we have two reasons to include it
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