[dimitrios1]

There isn't some universe where there exists a list of axiomatic, unfalisifable proofs for what or what doesn't constitute the foundations of scalability and robustness, rather, you have a tradition of development practices that have much more often lead you to scalability and robustness than than the alternatives, and Joe Armstrong was someone who trailblazed that tradition in blood sweat and tears so to speak, as well as a majority of developers here, many of which have had experience writing software that handles millions, sometimes hundreds of millions of requests per second who would very much likely agree with Joe on a lot of things.

Not everything people say on a discussion board is some scientific claim, subject to scientific inquiry and in need of a thesis defense. But if you really off-the-cuff dismiss Joe Armstrong's opinion on a matter because it hasn't met your criteria of proof, despite you thinking you are somehow being the rational scientist here, you are actually revealing your own stupidity.

[wredue]

The author claimed that immutability is a foundation for scalability and robustness.

I reject that claim.

In this comment, you simultaneously agree and disagree with me.

I don’t give a shit what Joe Armstrong says about immutability because the facts are the facts:

1) immutability cause performance problems

2) immutability significantly limits how you can manage data, which is counter to what computers are meant to do

3) immutability measurably does not reduce bugs in programs

I am not dismissing <insert name> off the cuff. I am dismissing them because their claim does not align with metrics you expect to improve as a result of their claim.

>it doesn’t have to be a scientific claim

When you are telling people to “make immutability a foundation of their programming”, you 100% are opening yourself to scientific scrutiny. If you cannot back up this claim with actual metrics, and you’re just going to say “hurr durr, just let me make claims without calling me out to providing evidence please”, why should anyone believe you?

[ilikehurdles]

You continue to express strong claims on strong claims without backing a single one of them up. And then you drop to mocking others for challenging those claims.

Have you ever heard the saying, “assertions made without evidence can be dismissed without evidence?” My experience differs.

Immutability has been the foundation of many of our large scale programs. It makes safe concurrent programming easier, and languages built around immutable data structures usually optimize memory handling in ways that are not available when simply writing “functional style” code in non-functional languages. ie under the hood they’re using persistent data structures, structural sharing, tail call optimization, etc.

[prophesi]

I think the main thing (in the context of Elixir) is that immutability gives you concurrency out-of-the-box, which in turn gives you predictability and scalability. It is very easy to spin up a couple of nodes that can communicate with each other thanks to this ecosystem.

[ch4s3]

> 3) immutability measurably does not reduce bugs in programs

I'd be curious to see how you back this claim up. Are you referring to something published that we can all go and read?

[sodapopcan]

It doesn't sound like you've used a natively mutable language before. If all you've ever used is immutable.js or something like that then I can understand why you think this way. Otherwise, you've gotta be trolling.

[mjhay]

A bit of the pot calling the kettle black here. You still aren't providing evidence yourself while making strong claims.

For your points:

1) Yes, immutability can cause performance problems in some contexts. However, it can also help in the whole. Mutability in concurrent systems requires all sorts of complications such as mutexes that slow things down considerably. In even single-threaded systems, mutability leads to defensive copying in practice. Furthermore, persistent data structures[0] exist for lists, dictionaries, etc., that achieve very good space and time performance by mutating internally while exposing an immutable interface.

At any rate, even if it is slower, most of the time the performance difference just doesn't matter.

2) How does it limit how you can manage data? It's still possible to mix immutable and mutable data if necessary, but immutable data can be transformed just as mutable data can.

3) You say it measurably does not reduce bugs in programs, again with no evidence. Immutability eliminates entire classes of commonly-encountered bugs, including many pernicious ones related to concurrency. These are bugs that happen commonly with mutable data, but simply don't for immutable data.

In addition, there is some limited empirical evidence to the contrary, which is rare for this kind of thing. Immutable-first Clojure had the lowest proportion of Github issues labeled as bugs, even beating out static languages. [1]

[0] https://en.wikipedia.org/wiki/Persistent_data_structure

[1] https://dl.acm.org/doi/10.1145/2635868.2635922

[HexDecOctBin]

> you have a tradition of development practices that have much more often lead you to scalability and robustness than than the alternatives

I'm not GP, but these traditions are usually not backed by any evidence but by cargo-culting and cult-of-personalities. Not to mention people who over-hype their favourite technologies to high heavens, poisoning the well for everyone else (no, most telecom industry doesn't run Erlang, Naughty Dog didn't ship Lisp on PlayStation 2, and Prolog didn't lead to fifth-generation computing).

[dimitrios1]

Do they need to be backed by evidence to be correct? What if they are just right? Do other companies not running Erlang mean its wrong? Because that's a bold argument that could be restated to disprove many things -- X technology claims to do Y well and has a track record of doing it really well, but Z companies don't use X technology, therefore...[insert whatever].

I don't believe in blindly believing things without evidence either, especially if I have never encountered them before, but I also don't believe in blindly dismissing experience of world renowned experts in their field because they didn't provide me a point by point prooftext of every claim they made (Again we aren't sitting here discussing a dissertation or mathematical proof). Their experience and what they've provided to the world is the evidence. We took this 19th century german ultra-materialist philosophy too far here in the west, and that's what gave us post modernism/poststructuralism with its disastrous consequences, but it still seems like we haven't learned anything from that.

The ancients had it right that theres different types of knowledge, and different ways of knowing things (and knowing them to be true, at least as far as it mattered). We here in the modern era with the most unfettered access to information have quite possibly the narrowest definition, ironically.

[HexDecOctBin]

> The ancients had it right that theres different types of knowledge

People hawking these traditions usually do for consulting money, not spiritual fulfilment. I am all for non-materialism, but only as long as it's not used to exploit me. Belonging to a post-Colonial country, I know exactly where that leads.