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Balance in all things Edit: eh, that comment didn’t really say much. What I meant was that there are classes of algorithms that are stateless. Maybe the most u

by e-dant 4y ago

Balance in all things Edit: eh, that comment didn’t really say much. What I meant was that there are classes of algorithms that are stateless. Maybe the most useful are proofs. Look, I’m a C++ dev. I live and breathe state. Weird, mostly-working gadgets are the real humans of the world. But that doesn’t mean I don’t use linear types and write unit tests for my function composition. Sure, I’ll let closures capture their context, and I’ll allow pass-by-reference in my APIs, but that doesn’t mean I encourage it.

stefncb 4y ago
> What I meant was that there are classes of algorithms that are stateless. Can you give me an example?
- e-dant 4y ago
  Practically speaking, any algorithm that does the same thing given the same input is said to be stateless. This property becomes more useful when you’re trying to prove something about a function’s behavior over a bunch of well-defined types. Languages like Haskell and Agda have these properties. Rust also has some of these properties by default. It has an affine type system (the borrow checker) enforces some guardrails on ad-hoc state manipulation. C++ has linear-esque types in its pointers and higher-kinded types in the concepts and constraints features.
  - stefncb 4y ago
    This is kind of nitpicky, but I'll say it anyway. An algorithm that does the same thing given the same input is deterministic aka referentially transparent aka pure, not stateless. Even this little snippet of Haskell is stateful: statefulFunction :: Int -> Int statefulFunction x = let y = x * x y + y The binding 'y' is state. Even if it's implicit, as in ((x * x) + (x * x)), it's still state. People seem to use "stateless" as a word for "doesn't mutate anything", which is kind of weird. Mutability has _nothing_ to do with having state.
    - e-dant 4y ago
      Algorithms != computation
      - stefncb 4y ago
        Then no algorithm holds state, because an algorithm is just a ruleset.
        e-dant 4y ago
        Sure. But the point is that functional languages are more declarative, holding very little control flow state. Procedural languages are the opposite. The computation I’m talking about is whether you’re for more of a von neumann target or a lambda calc target.

by e-dant 4y ago

stefncb 4y ago

> What I meant was that there are classes of algorithms that are stateless. Can you give me an example?

e-dant 4y ago
Practically speaking, any algorithm that does the same thing given the same input is said to be stateless. This property becomes more useful when you’re trying to prove something about a function’s behavior over a bunch of well-defined types. Languages like Haskell and Agda have these properties. Rust also has some of these properties by default. It has an affine type system (the borrow checker) enforces some guardrails on ad-hoc state manipulation. C++ has linear-esque types in its pointers and higher-kinded types in the concepts and constraints features.
- stefncb 4y ago
  This is kind of nitpicky, but I'll say it anyway. An algorithm that does the same thing given the same input is deterministic aka referentially transparent aka pure, not stateless. Even this little snippet of Haskell is stateful: statefulFunction :: Int -> Int statefulFunction x = let y = x * x y + y The binding 'y' is state. Even if it's implicit, as in ((x * x) + (x * x)), it's still state. People seem to use "stateless" as a word for "doesn't mutate anything", which is kind of weird. Mutability has _nothing_ to do with having state.
  - e-dant 4y ago
    Algorithms != computation
    - stefncb 4y ago
      Then no algorithm holds state, because an algorithm is just a ruleset.
      - e-dant 4y ago
        Sure. But the point is that functional languages are more declarative, holding very little control flow state. Procedural languages are the opposite. The computation I’m talking about is whether you’re for more of a von neumann target or a lambda calc target.