FINALLY, the Visitor Design Pattern makes Sense

[@JohnOliverAtHome]

Thanks Gui. Loved the (dynamic)this hint. It makes perfect sense and is so simple (now that I've seen it)

[@gui.ferreira]

Great to hear, John! Thanks for taking the time to leave a comment.

[@AndersBaumann]

The visitor is an attempt to implement a functional pattern in an OO language. But C# is getting more functional so now the visitor pattern can elegantly be replaced by pattern-matching expressions.

[@stevancosovic4706]

Very good explanation, thanks!

[@gui.ferreira]

Glad you enjoyed it!

[@tristanstricker967]

Great video. I think the strategy pattern may be a better fit for this example but visitor is still great. You are making great c# content. Keep up the good work

[@gui.ferreira]

Thanks! I think the Strategy Pattern can solve the same problem but doesn't give you the same benefits as the Visitor when you have a Composite. Thanks for the kind words, Tristan!

[@marcotroster8247]

The visitor pattern works great for serializing / deserializing syntax trees. That's the typical case I know.

[@gui.ferreira]

True! In some languages, it is the most efficient way to do it.

[@FreeMindInMotion]

Nice video. I have never used the pattern, but I will keep my eyes open. I like the dynamic type hint for the base class

[@gui.ferreira]

Glad you liked it 🙏 In fact, it's rarely used but it's good to know how it works.

[@vijaybhargavg8638]

This was brilliant.

[@gui.ferreira]

Thank you 🙏

[@MizenDaCat]

Hi Gui, do you have a video going through your IDE setup (themes, fonts, extensions)? If not, I think you should make one. What font are you using in this video?

[@gui.ferreira]

Hi! Thanks for the suggestion. I'm not sure if I want to do a video on this channel about it, but I will try to find a way to have that information out there. Regarding the Font, on the video, I'm using JetBrains Mono.

[@ilovepandaypoe6056]

real world scenario, all those permutations will be stored in the database? so need really to create many classes?

[@gui.ferreira]

You don't need to apply the visitor design pattern to domain or DB objects. It's a useful pattern for things like parsing or formatting

[@franciscoamaral9834]

Hi Gui, can you tell me what IDE are you using?

[@gui.ferreira]

Hey Francisco! JetBrains Rider.

[@vitek0585]

As option the extension methods for the particular type can replace this pattern

[@gui.ferreira]

Not that you can't do it in other ways in C#, but even then, it's not an "apples to apples" comparison.

[@HizusHiz]

Still doesn't make sense for c# because you can use pattern matching which will be faster.

[@jeffg4686]

The problem with the visitor pattern is fundamental. It breaks readability. It lacks domain understanding. To "Visit" isn't a verb with meaning.

[@ppg68]

While I agree, I find the idea of isolating the Methods into Objects quite useful, you only have to modify the code in one class without breaking anything else

[@jeffg4686]

@@ppg68 - I'm needs based. I never really found a need for this pattern. And when I see it used, it's never relevant, reads horrible, and fails to convince me that I need it. Just like the bridge pattern. Things start getting too pattern happy after a while...

[@Autumn4_love_your_]

Its a replacement for a type switch case

[@asusvenus]

Great content. Although, I think its way too zoomed in

[@gui.ferreira]

That's great feedback! Thanks! I've been using Presentation mode lately. I will revisit it 😉