# Haskell's missing mutable reference type

**URL:** <https://discourse.haskell.org/t/haskells-missing-mutable-reference-type/14248>\
**Category:** Links\
**Created:** [June 9, 2026, 9:32am UTC](https://discourse.haskell.org/t/haskells-missing-mutable-reference-type/14248 "2026-06-09T09:32:56Z")\
**Posts on this page:** 1\
**Showing post:** 12

<div class="post-metadata">

**Author:** ![BurningWitness](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.haskell.org/burningwitness/32/3665_2.png) [@BurningWitness](https://discourse.haskell.org/u/BurningWitness)\
**Post date:** [June 10, 2026, 5:47am UTC](https://discourse.haskell.org/t/haskells-missing-mutable-reference-type/14248/12 "2026-06-10T05:47:56Z")

</div>

> [@tomjaguarpaw](#):
>
> It can grow dynamically.

Yes, but that would require a completely different implementation. No matter how you slice it these references will have to live in CPU cache, and a static table is the most compact solution to that.

Much like with [[RFC] Mutable records as a GHC extension](https://discourse.haskell.org/t/rfc-mutable-records-as-a-ghc-extension/13886), I view a simple solution that fits the existing model as infinitely more preferable to both the status quo and the “dependent types are just a week away” line of approach.

---

_[View the full topic](https://discourse.haskell.org/t/haskells-missing-mutable-reference-type/14248)._