Coremods

[FlyingPerson23]

So I've heard a good bit about coremods, asm, and mixins and I'm kind of confused. What are they and what can they modify? When should they be used?

 

To be clear, I do not have any intention of making a coremod. I just want to know more about them.

[Draco18s]

16 minutes ago, diesieben07 said:

It's what forge uses and what it exposes in a JavaScript (yes, JavaScript) API to it's coremods so that the mods can use it to modify the loaded classes.

Related, does documentation for how to use the JS system exist somewhere?
I have no plans on using it, but beyond references I've seen to its existence (and one person linking to some code they wrote using it) I know nothing about it.

(And its fine if the answer is "no" or "yes" without saying where)

[FlyingPerson23]

Are coremods classes that use IFMLLoadingPlugin? Why does https://github.com/SleepyTrousers/EnderCore/blob/1.12/src/main/java/com/enderio/core/common/transform/EnderCorePlugin.java, what appears to be a coremod, also use mixin? Can you do some things with mixin that you can't with a coremod, or vice versa?

 

Do you need a special mod to use mixin?

Edited June 22, 2020 by FlyingPerson23

[FlyingPerson23]

Is a coremod the only way to modify another mod's behavior?

[FlyingPerson23]

Ok, so how else can you modify a class in another mod?