# Compile time: we can't find any impls for this multi dispatch fn?

**URL:** <https://discourse.julialang.org/t/compile-time-we-cant-find-any-impls-for-this-multi-dispatch-fn/94736>\
**Category:** General Usage\
**Created:** [February 16, 2023, 7:22pm UTC](https://discourse.julialang.org/t/compile-time-we-cant-find-any-impls-for-this-multi-dispatch-fn/94736 "2023-02-16T19:22:06Z")\
**Posts on this page:** 3\
**Page:** 2

<div class="post-metadata">

**Author:** ![jling](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jling/32/212909_2.png) [@jling](https://discourse.julialang.org/u/jling)\
**Post date:** [February 17, 2023, 2:39am UTC](https://discourse.julialang.org/t/compile-time-we-cant-find-any-impls-for-this-multi-dispatch-fn/94736/21 "2023-02-17T02:39:58Z")

</div>

depends on what you need. People have pointed you towards JET.jl for static analysis that understands typing system. And I have suggested Revise.jl so you don’t have to keep re-launching your program.

---

<div class="post-metadata">

**Author:** ![zeroexcuses](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/zeroexcuses/32/46846_2.png) [@zeroexcuses](https://discourse.julialang.org/u/zeroexcuses)\
**Post date:** [February 17, 2023, 10:55pm UTC](https://discourse.julialang.org/t/compile-time-we-cant-find-any-impls-for-this-multi-dispatch-fn/94736/22 "2023-02-17T22:55:50Z")

</div>

> [@jling](#):
>
> And I have suggested Revise.jl so you don’t have to keep re-launching your program.

How do you kill the existing webserver / restart a new webserver on file change with Revise.jl ?

---

<div class="post-metadata">

**Author:** ![tim.holy](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tim.holy/32/52_2.png) [@tim.holy](https://discourse.julialang.org/u/tim.holy)\
**Post date:** [February 19, 2023, 12:41pm UTC](https://discourse.julialang.org/t/compile-time-we-cant-find-any-impls-for-this-multi-dispatch-fn/94736/23 "2023-02-19T12:41:39Z")

</div>

I think @jling is proposing that you don’t have to: unlike Scala, Julia is capable of updating code in the middle of a running session. See [Developer reference · Revise.jl](https://timholy.github.io/Revise.jl/stable/dev_reference/#Revise.add_callback) and consider checking out Genie.jl, which I believe already implements all this for you.

[Previous page](https://discourse.julialang.org/t/compile-time-we-cant-find-any-impls-for-this-multi-dispatch-fn/94736.md?page=1)