[jokoon]

I stopped reading when he started using the visitor pattern

[ceronman]

The visitor pattern is very common in programming language implementations. I've seen it in the Rust compiler, in the Java Compiler, in the Go compiler and in the Roslyn C# compiler. Also used extensively in JetBrains' IDEs.

What do you have against this pattern? Or what is a better alternative?

[high_na_euv]

Visitor is heavy of code pattern that can be replaced by elegant, readable switch with exhaustive check, so all operations available by "Kind" enum are covered.

[kevthecoder]

The bytecode interpreter in the second half of the book doesn't use the visitor pattern.

[HarHarVeryFunny]

No, but his first "Tree-walk Interpreter" does - he builds an AST then uses the visitor pattern to interpret it.

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

[jokoon]

the parser does

[volemo]

What’s bad about the visitor pattern? /gen

[cfors]

https://grugbrain.dev/

grug very elated find big brain developer Bob Nystrom redeem the big brain tribe and write excellent book on recursive descent: Crafting Interpreters

book available online free, but grug highly recommend all interested grugs purchase book on general principle, provide much big brain advice and grug love book very much except visitor pattern (trap!)

Grug says bad.

In all seriousness, the rough argument is that it's a "big brain" way of thinking. It sounds great on paper, but is often times not the easiest machinery to have to manage when there are simpler options (e.g. just add a method).

[fuzztester]

Why?