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I wanted algebraic effects and handlers. Instead all I got was DI. 🤪
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Effects and handlers allow you to do similar stuff to DI (actually quite similar to aspect-oriented programming). They are pretty much accepted as a given in most PL conferences these days - but still need some stuff to be figured out. So at least we have this nice crate!
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Need good, guaranteed fusion of handlers like iterators enjoy in Rust before they are viable for a Rust-like language. The future is exciting though!
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do you have good examples of this? I have to admit I’m not familiar with effects and handlers, although I’ve noticed recently more and more haskell devs talk about effects
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I'll see if I can dig some up. As horrific as this sounds, think: "generalised exception handling". Effects are treated as things that you 'throw' and are handled somewhere else, potentially throwing new effects. All tracked in the type system.
So I could define a 'Log' effect with a constructor 'trace'. Then my application code could potentially do logging, but it's up to the top level caller of the application to do something with those thrown effects, potentially logging to standard out, or a file.
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Similar to the condition system in the Common Lisp and Dylan languages.
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Do you have examples of those effects/handlers in Rustt for beginners ?
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They aren't part of Rust at the moment, and there are no plans to add them as of yet, so it was somewhat mean of me to jokingly bring it up. Here is an interesting slideshow regarding multicore OCaml's upcoming effects and handlers though: kcsrk.info/slides/handler
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