There are questions about why Java doesn't support unsigned types and a few questions about dealing with unsigned types. I did some searching, and it appears that Scala also doesn't support unsigned data types. Is the limition in the language design of Java and Scala, in the generated bytecode, or is it in the JVM itself? Could there be some language that runs on the JVM and is otherwise identical to Java (or Scala), yet supports unsigned primitive data types?
Java Bytecode Specification only defines signed types:
The integral types are byte, short, int, and long, whose values are 8-bit, 16-bit, 32-bit, and 64-bit signed two's-complement integers
But a language implemented on top of the JVM can probably add an unsigned type at the syntactic level and just handle the conversion at the compilation stage.