Top-level comparison expressions

[springcomp]

Found this snippet in JEP-007:

"This is certainly a direction to take in the future, adding arbitrary expressions in a filter would be a backwards compatible change, so it’s not part of this JEP. Allow filter expressions as top level expressions. This would potentially just return true/false for any value that it matched.
This might be useful if you can combine this with something that can accept a list to use as a mask for filtering other elements."

Please, investigate its merits for upcoming new features.