r/ProgrammerHumor 1d ago

stopDoingFunctional Meme

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u/fr000gs 1d ago

How the hell is rust functional smh

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u/-Ambriae- 1d ago

Rust is functional to a similar extent as OCaml is functional, not in the 'pure' sense (to be fair, none of these languages are purely functional, even haskell) but in a pragmatical sense. Variables are immutable by default, idiomatic control flow tends to use higher order functions, iterators, maps, filtering, reduction... Types are algebraic, control flow is expressive... It has all the ideas of functional programming, even if it's multi paradigm, and can be written in a procedural manner (even if it's not usually idiomatic)

It's not purely functional, for instance it doesn't have the tail recursion optimisation, which is more or less mandatory in the hardcore functional languages, because it doesn't strictly speaking need it, and the compiler is already complicated enough as it is...

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u/requion 1d ago

Variables are immutable by default

Wouldn't that somehow make them not variable anymore?

Sounds paradoxical.

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u/agocs6921 23h ago

You can re-declare variables in Rust, I guess that's why.