[zasdffaa]

Doesn't java libs have a deq - a double-ended queue?

[jffry]

Yes, Java has java.util.Deque [1]. The purpose of this JEP is to add a more generic interface over the ordered collection types, which all have slightly different names for these operations.

[1] https://docs.oracle.com/en/java/javase/17/docs/api/java.base...