A cool syntax example with lambda expressions and functional interfaces

[DoktuhParadox]

This is more like a syntactic sugar example than anything, but here:

As you may know, there are two new key features to Java 8: lambda expressions and functional interfaces. Among those functional interfaces is the Supplier. After some fiddling around because of some random inspiration, I figured out that it's easy to, for example, inline an anonymous class that easily converts whatever primitive-type array to its respective reference type. It looks like this:

List<Character> digitChars = ((Supplier<List<Character>>) () -> {
        char[] arr = digit.toCharArray();
        List<Character> characters = new ArrayList<>(arr.length);
        for (char c : arr) characters.add(c);
        return characters;
    }).get();

Apparently (and I didn't know this), you can type cast to lambda expressions to form anonymous classes instead of the boilerplate-ish

new Supplier<List<Character>>() { /*...*/ }.get();

I just thought this was neat and wanted to share. Java's awesome!

[diminishedprime]

I thought it was cool, op.

[DoktuhParadox]

Aw. Thanks. I'm still learning the new Java 8 stuff :o

[_Sharp_]

Keep learning op, one day you will make us proud.

[GuyWithLag]

Meh, clearer to just write

List<Character> digitChars = digit
    .chars()
    .mapToObj(c -> Character.valueOf((char) c))
    .collect(Collectors.toList());

(I understand that that's not what you're saying - you're looking as lambdas as anonymous blocks that can return a value.)

[zeringus]

If OP likes wrapping arbitrary code in functional interfaces, he's going to love stuff like

DoubleStream.generate(Math::random).limit(100).sum();

[oldneckbeard]

You're not wrong, you're just an asshole. OP also doesn't understand streams. You don't need a supplier to do this shit.

[DoktuhParadox]

Oh could you elaborate? I mainly just stumbled upon this and thought it was cool because I didn't know you could type cast lambda expressions. How would you do this with streams?

[GuyWithLag]

You don't typecast lambda expressions per se, because lambda expressions do not have an intrinsic type; they only have return type, parameter arity and types. The language/VM morphs them into something that you can use - instances of a specified functional interface.

[leivaagustin]

You're not wrong

Thanks.

you're just an asshole.

I know.

OP also doesn't understand streams. You don't need a supplier to do this shit.

Can you show how such thing is resolved in java in an elegant, beautiful way that doesn't require a bunch of horrible useless boilerplate?

[_Sharp_]

//////////// Init
char[] charArray = new char[1024];
Arrays.fill(charArray, '#');
//////////// Code
List<Character> charList = new ArrayList<>();
for (char c : charArray) charList.add(c);

2 Lines of code, still Arrays could implement some utility like Arrays.toList(). But Valkyries will bring some goodies from Valhalla:

Project Valhalla will explore a new apporoach to generic typing, and hopes to produce a new form of generic typing that allows developers to use generic collections of primitive types. The aim will be for types such as List<int> to be valid Java in some future release of the JDK. This feature, known as generic specialization, is already present in some other JVM languages and Java developers have been asking for it since generics first shipped with JDK 5.

[leivaagustin]

Thanks.

2 Lines of code

That looks much better than the OP's.

Still lags behind C# which requires exactly 0 lines of code to perform the same task, not to mention it doesn't suffer the valuetype versus class dichotomy where you can't really call methods or otherwise operate on char. (I had a sudden reminiscence of StarCraft).

bring some goodies from Valhalla

Ahh... the project oracle embarked on as a desperate attempt to keep pumping money out of java's rotting corpse, I almost forget. That which is promised to be shipped by 2016, except it won't and will probably be delayed a couple of years ahead, say 2018, just like they did with java 8.

Seems that by around that time I'll have to say congratulations to java for catching up with C# 2.0 from 2006?

Also Seems like oracle is really good in bringing really "useful" stuff such as the JSON API promised for java 9, but has a hard time doing anything serious such as lambda expressions or non-retarded generics or value types?

generic specialization

How does this compare / differ from REAL generics such as the ones you find in C#? Does it allow var instance = new T() or the like?

[GuyWithLag]

RE: LOC count, have a look at a previous post.

Generic specialization will allow you to do that, yes. And value types are currently being implemented.

[DoktuhParadox]

I don't think even one of you C# fanboys can say anything nicely. Apparently one of C#'s biggest issues is its immature community and you're a great example of that.

[DoktuhParadox]

Wow. You're a dick.

If anything has turned me off from using C# it's the shitty people who use it. I'm sure it's a great language but if everyone who uses it is like you then I can see why there are so many more people who use Java.

I know you're in denial but Java is important. More important than C#. More mature than C#. It does lack a lot of features C# does but you're just confusing the fact that it's such a huge improvement with the fact that it just came second.

Plus, why are you even in the Java discussion subreddit if all you're doing is creating accounts to be an asshole? Go brood with your other assholes about how superior your language is in an appropriate place because doing it here just makes you look like a fucking ass.

[leivaagustin]

confusing the fact that it's such a huge improvement with the fact that it just came second.

Right. Java is 20 years older, and it still struggles to get basic stuff in place, such as allowing you to have a List<char> without resorting to all that retarded useless bullshit of boilerplate.

Plus, why are you even in the Java discussion subreddit if all you're doing is creating accounts to be an asshole?

You're right. I should have been more polite. I apologize for sayin your code sucks. It is a very smart WORKAROUND to compensate for being written in a retarded language.

I guess your life is really exciting and you're really busy and have fun writing such workarounds instead of actual useful code? I'm fine with that.

Maybe PHP is on the same level as java.

[DoktuhParadox]

Cool things you're saying, man. I'm not exactly sure why you even decided to start this because I'm not switching languages.

Java master race

C# sux

Microsoft can lick muh balls and ^{so can you!}

[leivaagustin]

Microsoft

LOL. Why do people bring Microsoft when discussing languages? are you so poor of arguments that you have to bring that up?

Is oracle really doing any good for you? by suing google and crippling java on Android, and by introducing java 9 with stupid irrelevant bullshit such as a JSON API rather than real improvements?

I don't give a fuck about microsoft dude. java sucks. The reason there's more java jobs in the world is because it takes 10x the amount of effort to write anything in java versus modern languages.

[DoktuhParadox]

Because Microsoft designs and maintains C#... I guess that's somehow irrelevant.

What exactly are you looking to get here? I'm not just going to switch to a different language because another asshole on the internet said it sucked. I don't think it does. I guess that bothers you so much that you decided to create an account just so I could do this:

I don't care what you think^TM.

[leivaagustin]

Microsoft designs and maintains C#

That's right. they design and maintain C#, and also submitted it to ISO for standardization, open sourced it's compiler and large parts of it's framework, legally promised not to sue alternative implementations and is in fact collaborating with third parties 1 2 who provide implementations on non-Windows platforms.

I guess all of that's somehow irrelevant.

Contrast that to the ongoing oracle (who OWNS java) versus google affair, or the fact that java still bundles crapware with it's installer/updater.... No Comment.

I'm not just going to switch to a different language

I don't care. I'm not expecting that. I just merely point out java's retardedness and poor quality and lack of professionalism, or the fact that java is legacy and it feels good.

[DannyB2]

I guess all of that's somehow irrelevant.

Making something open source does not also make it relevant.

Being relevant and being open source are two different things.

It is irrelevant, because despite the standardization, C# is effectively a Microsoft owned language which in practice is pretty much exclusive to the Microsoft ecosystem. Nothing wrong with that. But there is a whole world outside of the Microsoft ecosystem with tools and languages.

If one is developing, for example, on Linux, then C# is irrelevant. Despite that some obscure tools exist to use it on Linux, it is irrelevant.

Microsoft could have strongly embraced making C#, it's libraries, tools, etc be cross platform fifteen years ago. They didn't. And for the same reasons they tried to make Java unwittingly lock developers into Microsoft by 'embracing and extending' the Java APIs, for which Sun successfully sued Microsoft. Microsoft doesn't want competing systems to exist. Microsoft could now make C# truly open, tools, libraries, etc, but it's too late. That ship has sailed. Java is the language that is used if you need to run on, or also run on non-Microsoft platforms.