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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: 0.55s | source
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gethly ◴[31 Oct 25 08:53 UTC] No.45769775[source]▶
Variable is by definition mutable.

Constant is by definition immutable.

Why can't people get it through their heads in 2025? (I'm looking at you, Rust)

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mirpa ◴[31 Oct 25 09:09 UTC] No.45769884[source]▶
That depends on your definition. Programming languages often deviate from mathematics when it comes to definition of variables, functions etc. That is by choice, Haskell tried to be as close to mathematical definition as possible.
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1. latexr ◴[31 Oct 25 12:09 UTC] No.45771136[source]▶
You don’t need to make a mathematical argument, “variable” and “constant” have clear meanings in colloquial use which match the definitions of your parent comment.
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2. devnullbrain ◴[31 Oct 25 12:51 UTC] No.45771465[source]▶
So does 'parent'.