crisefd
Hi guys. I find myself in need of array-like data structure like the ones you find in Ruby, Python or Javascript.
I’m writing a genetic algorithm and when you deal with this kind of algorithms, you are constantly randomly selecting a position in it, slicing, appending, shuffling and combining. And using Lists for it just add time complexity given that for all of this operation the cost is almost always O(n).
I’ve tried using erlang’s :array but this is missing some of the feature above. Right now I’m workingaround the issue by using Maps with numerical keys, but again there are time when even this doesn’t cut it.
Is there a library I could use or maybe I need to create my own. Maybe wrapping Erlang’s :array or Elixir’s map to support all of my use cases?
Where Next?
Trending in Questions
Other Trending Topics
Latest on Elixir Forum
Sponsor Spotlight
Producing high quality Elixir screencasts since 2017.
Categories:
Sub Categories:
Forums
Popular Tags
- #ecto
- #liveview
- #troubleshooting
- #learning-elixir
- #library
- #deployment
- #erlang
- #testing
- #genserver
- #mix
- #absinthe
- #remote-other
- #otp
- #plug
- #how-to-question
- #macros
- #postgres
- #elixirconf
- #channels
- #exunit
- #discussion
- #code-sync
- #podcasts
- #javascript
- #onsite
- #dialyzer
- #docker
- #authentication
- #umbrella
- #full-time-contract
- #podcasts-by-brainlid
- #ai
- #ecto-query
- #elixirconf-us
- #blog-post
- #elixir-ls
- #phoenix_html
- #iex
- #graphql
- #genstage
- #websockets
- #supervisor
- #advent-of-code
- #distillery
- #processes
- #elixirconf-eu
- #api
- #forms
- #metaprogramming
- #hex
Our Sponsors
Supporting innovation across the BEAM ecosystem.
We build reliable cloud platforms for business-critical systems.
Catch errors, track performance, monitor hosts and more.
Error tracking, logs, uptime, and Just Enough APM. Built for developers.
Elixir, Erlang & BEAM conferences from Code Sync - join us in 2026!
Master modern tools, write cleaner code, and tackle real-world challenges.
**Building the future of software with AI, trust, and human connection.**
The deployment platform built for Elixir: PaaS ease, VPS control.
The team behind Membrane, Popcorn, LiveDebugger. Available for hire.
Courses that'll move you from confusion to "Aha, now I get it!"
First Post!- Show Best Posts
- Show All (oldest first)
- Show All (newest first)
hauleth
There are 3 approaches you can take:
:arrayIt depends on your use case which one of these will be most efficient. In general there is no simple and efficient way to shuffle any structure in Elixir.
Most Liked
preciz
I almost forgot:
When I was playing with genetic algorithms, I successfully sped up things with the Matrex library.
ityonemo
Keep in mind that the data structure you are proposing is ill suited for distributed systems, which is why it’s not a first class citizen of the BEAM. I’m a math major working at a deep learning company, and maybe it’s Stockholm syndrome but I’m ok with this separation of concerns and having arrays be second class citizens of the ecosystem. Distribution is hard, and the trade-off of making arrays second class is, in my mind “totally worth it” to make distribution easy.
preciz
There is also
:atomics.If 64 bit integers are suitable for you. You can also use them as a bit array. (I have a lib to help with that: Abit)
Last Post!
OvermindDL1
Ah, both of those are fixed in a couple of ways!
For array slicing I’ve found I just use Elixir ranges, like
1..12or so, simple enough. And making a simple wrapper that just wraps the erlang module but adds support for range indexing and giving it a prettier inspect display is quite simple too.Wouldn’t surprise me if someone already did it on hex.pm actually?
Those aren’t mutation on the beam, those are sending immutable messages to other locations. The BEAM abstracts mutation via Algebraic Effects, I.E. it’s messages. Editing an array via messages is fine, that’s basically how it would be via a NIF or emulating it via another process, but editing an array in-process would break some invariants, hence the purpose of NIF’s and so forth.
I would highly not recommend it, keep mutation beyond message or NIF (which is still essentially a message as the storage exists beyond the process) bounds. Allowing it in-process will break code invariants.