[esafak]

Java's sealed interfaces enable typing errors.

https://blogs.oracle.com/javamagazine/post/java-sealed-class...

[keybored]

Although syntactically lightweight it is the opposite of.

[esafak]

I agree; Java is constitutionally incapable of being lightweight. I much prefer Typescript's union syntax. I'm glad Python copied it.

[peterashford]

records are lightweight