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John Carmack on mutable variables

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498 points azhenley | 1 comments | 31 Oct 25 02:34 UTC | HN request time: 0.2s | 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. ehsankia ◴[31 Oct 25 03:03 UTC] No.45767892[source]▶
functional programming has a lot of wonderful concepts, which are very interesting in theory, but in practice, the strictness of it edges on annoying and greatly hurts velocity.

Python has a lot of functional-like patterns and constructs, but it's not a pure functional language. Similarly, Python these days allow you to adds as much type information as you want which can provide you a ton of static checks, but it's not forced you like other typed languages. If some random private function is too messy to annotate and not worth it, you can just skip it.

I like the flexibility, since it leads to velocity and also just straight up more enjoyable.