What if a hypothetical new operator used only characters already not allowed in identifiers and composed of characters not allowed in contiguous operator sequences.
Consider: :=, <-=, <|, $,
AFAIK, _ isn't an operator in Java (http://docs.oracle.com/javase/specs/jls/se8/html/jls-3.html#...). The language does allow _ to be used as a separator in numeric literals.
Is there a new operator in some upcoming version of the language specification?
_ is a keyword in Java 9.
It isn't an operator though, right?
That'd invalidate a lot of programs. Just like how the new _ operator in Java is killing a lot of code right now.
Every symbol that can be used... has been used. "Move" is the meaning of the operator in any case. Its no less readable than say... Python's __lshift__ or __add__.