# Will Extension classes be part of upcoming Kotlin versions?

**URL:** <https://discuss.kotlinlang.org/t/will-extension-classes-be-part-of-upcoming-kotlin-versions/11201>\
**Category:** Language Design\
**Created:** [January 17, 2019, 7:40am UTC](https://discuss.kotlinlang.org/t/will-extension-classes-be-part-of-upcoming-kotlin-versions/11201 "2019-01-17T07:40:18Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![silwar](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.kotlinlang.org/silwar/32/3075_2.png) [@silwar](https://discuss.kotlinlang.org/u/silwar)\
**Post date:** [January 17, 2019, 7:40am UTC](https://discuss.kotlinlang.org/t/will-extension-classes-be-part-of-upcoming-kotlin-versions/11201/1 "2019-01-17T07:40:18Z")

</div>

I find **extension classes** in swift a useful feature to combine all extension functions for a single class.  
I understand that this can be achieved by manually separating extension functions class wise in different files but it will be more useful if such classes can be part of Kotlin itself.  
With this feature, classes with more functionality can be divided into small classes (main classes + extension classes)

Anybody knows if extension classes is part of roadmap for Kotlin in upcoming versions? or can we request such feature to Kotlin team?

---

<div class="post-metadata">

**Author:** ![fvasco](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.kotlinlang.org/fvasco/32/1961_2.png) [@fvasco](https://discuss.kotlinlang.org/u/fvasco)\
**Post date:** [January 17, 2019, 8:58am UTC](https://discuss.kotlinlang.org/t/will-extension-classes-be-part-of-upcoming-kotlin-versions/11201/2 "2019-01-17T08:58:57Z")

</div>

The [KEEP 87](https://github.com/Kotlin/KEEP/pull/87) cover your use case [https://github.com/47deg/KEEP/blob/master/proposals/type-classes.md](https://github.com/47deg/KEEP/blob/master/proposals/type-classes.md) ?

Did you known [http://arrow-kt.io/](http://arrow-kt.io/) ?

---

<div class="post-metadata">

**Author:** ![silwar](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.kotlinlang.org/silwar/32/3075_2.png) [@silwar](https://discuss.kotlinlang.org/u/silwar)\
**Post date:** [January 17, 2019, 9:16am UTC](https://discuss.kotlinlang.org/t/will-extension-classes-be-part-of-upcoming-kotlin-versions/11201/3 "2019-01-17T09:16:27Z")

</div>

aah… [KEEP 87](https://github.com/Kotlin/KEEP/pull/87) is similar… actually quite comprehensive version of my suggestion.  
I was unaware of [http://arrow-kt-io/](http://arrow-kt-io/). I will go through it.

Thanks for sharing both link 🙂 👍