# Julia's in.() seems slow compared to R's %in%

**URL:** https://discourse.julialang.org/t/julias-in-seems-slow-compared-to-rs-in/23900
**Category:** Performance
**Created:** [May 6, 2019, 7:06am UTC](https://discourse.julialang.org/t/julias-in-seems-slow-compared-to-rs-in/23900 "2019-05-06T07:06:21Z")
**Posts on this page:** 1
**Page:** 3

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### Author: ![mkborregaard](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mkborregaard/32/556_2.png) [@mkborregaard](https://discourse.julialang.org/u/mkborregaard)
#### Post date: [May 9, 2019, 8:05pm UTC](https://discourse.julialang.org/t/julias-in-seems-slow-compared-to-rs-in/23900/41 "2019-05-09T20:05:36Z")

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OK, I’ve opened the PR as promised: [Specialized broadcasted on `in` by mkborregaard · Pull Request #31980 · JuliaLang/julia · GitHub](https://github.com/JuliaLang/julia/pull/31980) I hope people feel their position is fairly represented, otherwise the floor is open 🙂

> [@tkluck](#):
>
> A leaky abstraction is _exactly_ what we see here: performance is a very typical observable effect that betrays the implementation

Thanks for that really interesting link. Really cool, and I agree. But note also this quote " **All non-trivial abstractions, to some degree, are leaky.**" . Still abstractions like this one are tremendously useful.

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