[1.12.2] Not sure on Predicate<IBlockState> initialization

[SeptemberBlue]

So I was trying to create ores for the end, and I noticed that the constructor for the WorldGenMinable had a third argument which I'm assuming which blocks can be replaced. I'm referring to the "Predicate<IBlockState>". The problem is that I don't know how to use predicate.

 

Assuming my IBlockState is

Blocks.END_STONE.getDefaultState()

How would I turn this into a Predicate?

[SeptemberBlue]

5 hours ago, diesieben07 said:

...provide something that returns true when the block passed in is the one you want to replace.

That's the reason I made this topic, I've never even seen a predicate before, and I don't know what to pass it.

I saw this as an example of initializing a predicate:

Predicate<String> allCaps = new Predicate<String>();

The problem is that it's giving me an error that "Cannot instantiate the type Predicate<String>". So how am I supposed to initialize it correctly?

[SeptemberBlue]

4 hours ago, diesieben07 said:

Predicate is an interface. If you do not know what an interface is or how it works, you need to learn basic Java first.

https://docs.oracle.com/javase/tutorial/java/IandI/createinterface.html

Also relevant (but you should probably just read all of those tutorials if you don't know Java):

https://docs.oracle.com/javase/tutorial/java/javaOO/lambdaexpressions.html

 

Please stop acting like I've had 0 experience with Java, it doesn't help at all. I know enough Java to make a competent program with it.

 

So with that said, I have two questions:

1. I've only really seen the <> brackets used with ArrayList. What exactly did they do again?

2. Given that Predicate is an interface, are there any classes that implement it (specifically minecraft classes)?

[SeptemberBlue]

34 minutes ago, diesieben07 said:

Use your IDE. 

Ok, so I'm using eclipse. I've barely used it before, so I don't know much about it.

 

Also, why can't you just send a line of code that properly initializes the Predicate<IBlockState>? I'm guessing it'll be just one line, like most initializations, and it's getting kind of annoying when this topic could've been solved in one comment.

[SeptemberBlue]

Alright, this is clearly going nowhere.

 

I'm just going to extend the WorldGenMinable class and override a method.

[SeptemberBlue]

Didn't notice the StonePredicate class before.

 

Made an EndStonePredicate class, passed that as an argument and now everything works fine.