Final Keyword: Advantages and disadvantages

[john-bv]

In essence, the idea of a final keyword on both a class and variable could be useful, however it also seems redundant, here's why:
If we have a class, type sharp automatically reserves the class in the namespace, we CAN NOT create a class with the same name in an existing namespace, however final keyword would enforce this further, and disallow this class name from being used at all again. Essentially blocking the name from being used again, while this could work as an advantage, it also seems like a disadvantage for projects that may have the same names but have different functionality.

[john-bv]

Closing with the following:

I am in favor of adding final classes, however the T# compiler will not respect the keyword outside the given scope it's used in. For instance, you may declare a class with the same name, outside the given namespace.

This means something like:

// File in: test/blah/mod.ts
final class Test {}

will now be reserved and you may no longer create a class name with "Test" in test/blah as test/blah/mod.ts is preventing you from doing so.

In addition to this, final classes can not be modified, and will be treated as static (hence being final), this means you can not extend a final class or attempt to hijack it using a decorator.