How can I compile a regex in Elasticsearch 5x's Painless syntax

Question

I have a need to compile a regex defined by a parameter in Painless.

My initial assumption would be that I could do something similar to the following:

Pattern p = Pattern.compile(params.myPattern);

However, I am getting the following error:

Caused by: java.lang.IllegalArgumentException: Unknown call [compile] with [1] arguments on type [Pattern].

Perhaps there is another way to convert a string into a Pattern object in Painless?