Why does Java allow control characters in its identifiers?

Question

The Mystery

In exploring precisely which characters were permitted in Java identifiers, I have stumbled upon something so extremely curious that it seems nearly ce

Answer 1

The Java Language Specification section 3.8 defers to Character.isJavaIdentifierStart() and Character.isJavaIdentifierPart(). The latter, among other conditions, has Character.isIdentifierIgnorable(), which allows non-whitespace control characters (including whole C1 range, see the link for the list).