val ` -!"#$%^&()*+,-=?@^_{|}~😡` = ""
Yes, that's write, emojis are allowed too =)
.:/\[]<>
- https://docs.oracle.com/javase/specs/jvms/se11/html/jvms-4.html#jvms-4.2
- https://kotlinlang.org/docs/reference/java-interop.html#escaping-for-java-identifiers-that-are-keywords-in-kotlin
- https://kotlinlang.org/docs/reference/coding-conventions.html#naming-rules
- https://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html#jvms-4.2.2
Another useful link: https://kotlinlang.org/spec/syntax-and-grammar.html#identifiers