<@U0B8ZP13Q> yes we have Free, FreeApplicative, Co...

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[raulraja]

@cedric yes we have Free, FreeApplicative, Cofree and many others in Kategory already and usable. Our type checked docs in Kategory are built with ank which is a markdown snippet evaluator based on Free :
https://github.com/kategory/kategory/blob/master/ank-core/src/main/kotlin/io/kategory/ank/algebra.kt
https://github.com/kategory/kategory/blob/master/ank-core/src/main/kotlin/io/kategory/ank/interpreter.kt

[raulraja]

4 thread request so here it goes. We have encoded Free monads and applicatives in http://kategory.io/ . Free monads and applicatives beside their FP jargon are useful data structures that allow you to decouple program declaration from interpretation.

[raulraja]

Free algebras are defined as ADT, ops you can reify in a data structure that when you flatMap over it it builds the declaration of a program.

[raulraja]

Once you write an interpreter which is a natural transformation from your ADT to a target runtime datatype you can interpret your program.

[raulraja]

Those programs are stack safe by nature because the Free monad is also stack safe

[raulraja]

You can save your entire program as a value and interpret it as many time as you wish to different runtimes.

[raulraja]

All concerns of an application can be reified in terms of a free algebra so you can model error handling, effect capturing, dependency injection etc.

[raulraja]

Biz logic stays entirely decoupled from API and integrations in the implementation.

[raulraja]

There are no inheritance relationships or constrains as to how you combine your programs.

[raulraja]

Entire frameworks and libraries in Scala build a top Free monads. For example slick and doobie for database access. Fetch for efitient data fetching over heterogeneous datasources and many more. http://frees.io as well which is from many of the Kategory contributors and sponsored by 47 Degrees.

[raulraja]

We are porting a lot of those libs over to Kotlin

[raulraja]

Because with Free structures you can inspect programs before running them and optimizing them so we can do things like dedup, batching, cacheing, etc... all thanks to Free and FreeApplicative

[raulraja]

If anybody wants any gore details about anything in particular I'll be happy to answer questions here or in #functional #kategory EOF.