I remember Martin Odersky explaining how the Scala compiler has to do a lot of work to compile FP code to a JVM that is mostly geared for the Java language only

I remember Martin Odersky explaining how the Scala compiler has to do a lot of work to compile FP code to a JVM that is mostly geared for the Java language only. Because of that the compiler is well positioned to compile to other targets as well. Like Javascript or LLVM. Are you talking about compromises in the language or the standard library? In the language itself I can only think of type erasure for generics having to follow the JVM choice.