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The Grug Brained Developer (2022)

(grugbrain.dev)
1087 points smartmic | 1 comments | 17 Jun 25 20:24 UTC | HN request time: 0.424s | source
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12_throw_away ◴[17 Jun 25 21:01 UTC] No.44303909[source]▶
This has by far the best discussion of the visitor pattern I've yet to come across.
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dgb23 ◴[17 Jun 25 21:47 UTC] No.44304309[source]▶
I don't work in typical OO codebases, so I wasn't aware of what the visitor pattern even is. But there's an _excellent_ book about building an interpreter (and vm) "crafting interpreters". It has a section where it uses the visitor pattern.

https://craftinginterpreters.com/representing-code.html#the-...

I remember reading through it and not understanding why it had to be this complicated and then just used a tagged union instead.

Maybe I'm too stupid for OO. But I think that's kind of the point of the grug article as well. Why burden ourselves with indirection and complexity when there's a more straight forward way?

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1. zelphirkalt ◴[19 Jun 25 08:25 UTC] No.44316589[source]▶
If you work in a language that can pass closures as arguments, then you don't need a special visitor pattern. It is one of those patterns, that exists because of limitations of languages. Or, if you want to call passing a closure visitor pattern in some cases, it becomes so natural, that it does not deserve special mention as something out of the ordinary. You may be too smart for it.