Відео

Won't this cause us to always check each moving ability to see which is null and which isn't? Every time I want to do something with a vehicle object, I'll have spaghetti code if statements checking to see which ability it has that's not null. Don't get me wrong, this solution clearly has benefits over inheritance but let's be clear about the drawbacks too.

nice... I use c# all the time and did not know this and wish it had this. Now we just need a myValue.ClampToZero() extension. (myValue < 0 ? 0 : myValue) This is instead of Math.Max(0, MyValue).

i'm afraid C# is becoming a language for wankers

This time, the Turkish Ice cream man flips too long for the C#hildren to take the F#luffy.

(Native speaker is Chinese, the following is from machine translation) Suddenly I realized that using static actually breaks the boundary between object-oriented programming languages and functional programming languages.

Lean

Code is, on average, written once and read 10x. Write your code to be easily read and understood. If I have to do mental olympics to read and understand your code, it's probably too condensed. Shorter != better.

Amazing! You are an articulate person, it would be nice to get a DDD course (An affordable one) from you. It would have covered your programming mastery and eloquence to deliver the goods.

Thank you very much for this great video! The advantages of fluent interfaces become very clear. However, for complex use cases, writing a fluent interface can become tedious. To address this, you might find the M31.FluentAPI source generator library I created helpful. Happy coding!

Well. It's awesome that you can do this. Convolutedness of signatures is a bit of a problem. All delegate types are incompatible with one another even if they have the same signature (seen as different types by compiler). You can get around this by explicitly typing (wrapping) one. Prime example is that you can't assign Func<A, bool> to Predicate<A> and vice versa. It's gonna be interesting to see how C# tackles these incoveniences. Functional first languages win here. Like Haskell or F#.

In whole honesty this is exactly where functional C# loses to regular F# and where it becomes obvious it’s not functional first. It sure can be functional enough, but should it?

Do this at work just to troll everybody. You dont understand it? Your problem. Lol!

To return items from primary of alternate if primary contains nothing. Couldn't we also use two foreach loops where first will set found boolean and afterwards return if found?

I agree with your description of functional programming. I agree to most of what you do. But there is one slight problem. Functions aren't first class citizens in C# as far as I know. Functions cannot exist on their own. They must exist on a class. A delegate is basically a type description for a function. Its header becomes its type in a sense, because it is. But a description is not a concrete instance. Those must live in the form of methods on objects. Even static methods are just tricks, they are still part of a class. A first class function can live on its own. That means no classes. It can be created, defined, all without a class, or a type, it just exists. Static methods are just a trick (in a sense, they do have use in an OO context these days within C#). Delegates are indeed WAY nicer then only using Func and Action! I agree. Makes it look more like Haskell, where every function needs an abstract type definition (not called that, but we get the idea).

Why have ToOption() when you can just have an implicit conversion operator from T to Option<T>? That way you can transparently declare parameters of type Option<T> and pass ordinary objects into them. Also, why not have `public static Option<T> None = new();` as a single instance? There is no real need to have it as a method. In fact, you could sacrifice type information and introduce a non-generic (Value)Option<T> just to have a `None` member so it could be referred to without extra type information.

The use of terminology here is not 100% correct, because normally `Reduce()` does a completely different thing. The correct term here would be something like `Otherwise()` or something to that effect. `Map()` is more correct though you could equally call it `Select()` (per LINQ terminology), `Take()` or something else. Also, in `GetLabel()`, the initial call to `person.` can throw if it's null, and this call isn't handled here by the Maybe monad.

I'm going to have to watch this a few times. My OO ordered brain resists the truth. :)

Thanks for the video

This type of expert level coding gives me orgasm😂

mind blown!

You just showcased one of the main barriers I have had with functional paradigms in c#: the complexity in the signatures. Whether we like it or not, c# is not designed for this, and this is a real pain in the rear end specifically when you work on a team and people have a hard time following (heck, I have tough times myself!) With that said, that trick with the delegate definition is a good one that I am taking note of it. What a shame that currying has to be this complicated (in terms of readability) as it is one of those functional tools that can be very handy in several scenarios to remove a bunch of interfaces and abstract clases. Great explanation!

So we're using FilterBooks to return a delegate of type Filter<BookType> which is extended by the static extension method "for", which takes a function that returns Task<IEnumerable<Books>>, and returns a function that has a search string parameter, and then this function is passed to the PromptAndReport method which matches the FilteredDataSource<BookType> delegate? Then finally, it pass it a string to do the filtering? My God.

as much as i like FP, i worry my juniors wont be able to understand my convoluted delegates

Program.cs line 10 is dataSource a great name for the argument?

Great video, really puts into perspective how C# has been evolving over the years. How often do you get to write this type of code in production? Do you find it confuses people that are accustomed to the traditional OOP way of doing things, how do you get over that? Pozdrav iz Finsoft/Fincore-a !

Well thanks for the video. My personal opinion is, that I would have stopped before the introduction of "OrElse". I find the "FirstOf()" outer call clearer, because all three calls inside are on the same level. With OrElse on the other hand, the first call is outside the OrElse method call, but the other two inside OrElse. I find that ugly. But that’s probably just my opinion. For the same reason I prefer "Enumerable.Zip(a,b,…)" instead of "a.Zip(b, …)". (Usually with line breaks between the parameters.)

I understood nothing. 😢

I really try to understand your videos, but for some reason most of them are not clear at all😶

The main use case I've found for currying has actually been in UI logic. I.e. you have some inputs that should trigger redraws of other parts of the UI along with some other custom actions? Tedious without currying, simple with currying.

You have to admit F# reads a heck of a lot easier than whatever this C# "we must define everything" mess is... 😅

Please take 1000 likes and thanks from me for your excellent Job. I am following you from the Pluralsight course. I have become a fan of your UA-cam videos.

I use this very often in unity

ua-cam.com/video/KFx9XHpoYV4/v-deo.html "Without further validation..." doesn't this lead to a runtime validation error though if someone casts an empty string to a NonEmptyString? even without having to cast and reversing the implicit operator you would get a runtime exception and provides no guard against someone creating a book with an empty title? ---LinqPad--- void Main() { var myString = "test"; var myEmptyString = ""; var book = new Book(Title: myEmptyString); book.Dump(); } public record struct NonEmptyString(string Value) { public string Value { get; init; } = !string.IsNullOrWhiteSpace(Value) ? Value.Trim() : throw new ArgumentException("Value cannot be null or white space.", nameof(Value)); public static implicit operator NonEmptyString(string b) => new NonEmptyString(b); } record Book(NonEmptyString Title); --Output at runtime-- ArgumentException••• Value cannot be null or white space. (Parameter 'Value')

i would say that using “delay” is a bug 🐛.

As far as I can remember, I used to use this method in Unity game engine (Mathf.Clamp) a long time ago. I am surprised that .Net hasn't had one until recently. Good reminder. Thank you!

I'm really spoiled in that i learned to program with large math libraries that are not only documented well, but super fast and with context appropriate typing. The C# Math class is about barely passable, Clamp is among the first methods that should reside there, but how about bounded Remap, Unbound Remap, Rescale, half the lower level math ops nowhere to be seen. Custom Math class is always among the first classes i implement if one doesn't exist already.

Very nice!

Nice, I forgot about Clamp but now I have the perfect idea where to use it in my code, thanks! Just saying, the way you've defined your Percentage class, it is still possible to initialize it with an invalid value: "var invalid = new Percentage(75) { Value = -12345 };". Change the init setter to private set to disallow this.

Thank you

You Speak too bad and your accent is a disaster that left the video at minute 2

4:05 & 4.50 Thank you for mentioning the reasoning behind to position of CancellationToken here.

var result = list.Select((p, i) => new { p, i}).OrderBy(p => p.p != 0 ? p.i : list.Count + 1).Select(p => p.p); Console.WriteLine(String.Join(", ", result));

Sorry but i lack a bit of experience on this topic. Are the models like Person and Tag supposed to be on their own or can they be used as complex types for EF core? I guess they are the model that is core tho the app and it is then used to populate entities? For example if i try to use them and migrate EF fail since it cant bind Name and Surname to properties on the Person type, i think there are workarounds for it but is logically wrong?

Great stuff. Thank you! But how can I implement passimistic and optimistic locking using DDD aggregate and EF Cote?

You are a phenomenon I've found lately. Besides the rich content I especially love the passion for coding coming out of your voice!

One word separates the noobs from the pros: multithreading.

You criticize the junior programmer, but without more context their implementation is just as fast as the second solution. The rest are overly complicated and have unnecessary overhead for the simple problem

This is not code, this is art. Thank you sir.

wow

Great vid and love your accent and storytelling!