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John Carmack on mutable variables

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498 points azhenley | 2 comments | 31 Oct 25 02:34 UTC | HN request time: 0.441s | source
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munchler ◴[31 Oct 25 02:54 UTC] No.45767832[source]▶
> Making almost every variable const at initialization is good practice. I wish it was the default, and mutable was a keyword.

It's funny how functional programming is slowly becoming the best practice for modern code (pure functions, no side-effects), yet functional programming languages are still considered fringe tech for some reason.

If you want a language where const is the default and mutable is a keyword, try F# for starters. I switched and never looked back.

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1. keeda ◴[31 Oct 25 03:17 UTC] No.45767989[source]▶
We are still living with the hangover of C, which was designed for the resource-starved machines of eons ago, and whose style later languages felt they had to copy to get any kind of adoption. (And as you point out, that is how things turned out.)

My bet is functional programming will become more and more prevalent as people figure out how to get AI-assisted coding to work reliably. For the very reasons you stated, functional principles make the code modular and easy to reason about, which works very well for LLMs.

However, precisely because functional programming languages are less popular and hence under-represented in the training data, AI might not work well with them and they will probably continue to remain fringe.

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2. johnisgood ◴[31 Oct 25 13:44 UTC] No.45771913[source]▶
Just use OCaml in which you can mix imperative, functional, and OOP. I use all of them in a single codebase, whichever, wherever appropriate.