Is it possible to write an LLDB extension in Python which provides a function which can be used in expressions at the LLDB command-line, similar to this for GDB?

I’ve searched the LLDB Python API documentation and found how to add commands, type formatters, and synthetic child providers. I’m in the process of creating scripts using these facilities (with underlying code portable between LLDB and GDB). We have a convenience function which we use in GDB, and are considering writing more, but if that’s not possible in LLDB we might use some sort of command instead.