What is the status of "CREATE FUNCTION"?

[qrilka]

I was doing some basic calculations using datafusion-cli and found that I repeat a couple of function invocations there. So I thought that it could be cool to have that in a function so I tried and saw this:

> create function foo();
Invalid or Unsupported Configuration: Function factory has not been configured``

Searching the documentation of Datafusion gave me no good results so I wonder what does this error mean (maybe it could be improved?) and if it's even planned to support UDFs defined from CLI and not in custom Rust code (which would need some extra work to plug it into datafusion-cli)