DOdorianm·Nov 5, 2016
There are a few immutability options, for instance Hamster: https://github.com/hamstergem/hamster/blob/core/README.md
In Be careful about what you dislikehamstergem
hamster
Ruby2010–2016
hamstergem / hamster
hamster
Efficient, Immutable, Thread-Safe Collection classes for Ruby
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Efficient, Immutable, Thread-Safe Collection classes for Ruby
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This week on Hacker News
Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 3:56:07 PM UTC.
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HN mentions by year13 dated mentions
Observed mentions: 2010-01-09 07:01:00 UTC to 2016-11-05 14:20:57 UTC.
Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.
View mention counts and date ranges
| Period | Start (UTC) | End (exclusive, UTC) | Mentions | Submissions | Comments |
|---|---|---|---|---|---|
| 2010 | 2010-01-01 00:00:00 UTC | 2011-01-01 00:00:00 UTC | 3 | 2 | 1 |
| 2011 | 2011-01-01 00:00:00 UTC | 2012-01-01 00:00:00 UTC | 1 | 0 | 1 |
| 2012 | 2012-01-01 00:00:00 UTC | 2013-01-01 00:00:00 UTC | 3 | 3 | 0 |
| 2013 | 2013-01-01 00:00:00 UTC | 2014-01-01 00:00:00 UTC | 2 | 0 | 2 |
| 2014 | 2014-01-01 00:00:00 UTC | 2015-01-01 00:00:00 UTC | 1 | 1 | 0 |
| 2015 | 2015-01-01 00:00:00 UTC | 2016-01-01 00:00:00 UTC | 2 | 0 | 2 |
| 2016 | 2016-01-01 00:00:00 UTC | 2017-01-01 00:00:00 UTC | 1 | 0 | 1 |
What Hacker News says
13 sourcesI have some bad news for you (and for Edsger W. Dijkstra, who you would probably be a fan of)- In the "real world" of programming work, you will likely rarely encounter most of those things. Real-world dev is NOT about "computer science proper". (Unless you're building a language from scratch. Which is like 0.01% of all programming work.) You should of course be aware of them and what they do, and when you think you need them you should Google them and learn them then (and of course be able to do so).
Sometimes you need to switch languages- Perhaps you want the "look and feel" of pencil art which you can't do with pen-driven art without A LOT of work.
You can implement immutable data structures in Ruby- for example, see the Hamster gem here https://github.com/hamstergem/hamster - but 1) it is much, much slower, 2) none of the other gem co
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de you will call into will use Hamster 3) you actually have to code differently to Hamster data structures than to the built-in Ruby ones.
Just because you CAN make pencil-art with pens, doesn't mean that's the "happy path."
And just because you can represent every possible computer operation as a series of lambda functions (see "Programming With Nothing" here, great article: http://codon.com/programming-with-nothing) doesn't mean you should.
Well you could use this:
https://github.com/hamstergem/hamster
In My Weird RubyEfficient, Immutable, Thread-Safe Collection classes for Ruby
1 points · Open discussionIIUC they pulled out clojure's clojurescript projected core structures so you can use it ~pojo ?
Recenlty I saw https://github.com/harukizaemon/hamster , similarly immutable, structure sharing, persistent data structures
It's becoming mainstream ...
In Functional data structures in JavaScript with Morihttps://github.com/harukizaemon/hamster is apparently quite good.
In The Sorry State of Trie Implementations in PythonHamster: Efficient, Immutable, Thread-Safe Collection classes for Ruby
3 points · Open discussionHamster - Efficient, Immutable, Thread-Safe Collection classes for Ruby
39 points · Open discussionEfficient, Immutable, Thread-Safe Collection classes for Ruby
2 points · Open discussionThis article is a great example of what's so great about the Python ecosystem. I don't think I've ever seen something like this for the Ruby data structures (except for in the Hamster data structure project [1], which has solid performance data).
[1] https://github.com/harukizaemon/hamster
In Time Complexity of Python Data StructuresEfficient, Immutable, Thread-Safe Collection classes for Ruby
1 points · Open discussionI came across a library for persistent data structures in Ruby yesterday: http://github.com/harukizaemon/hamster
In "Purely Functional Data Structures" by Chris Okasaki [pdf]Hamster: Immutable data structures in Ruby
2 points · Open discussion