Thanks for your reply. Yes I agree it is a bit weird why I am trying to do so.
I am working on a project called Cohort Analysis Platform (CAP) in Garvan Institute of Medical Research.
The project is all about Codeless Analysis at Scale where user describe analysis in a YAML file and then CAP take care of it.
CAP is going to utilise many tools (i.e. VEP, Plink, PRSice) but it mainly use Hail for almost everything.
I want to be able to have Hail Expression in the YAML file (i.e. for annotation or aggregation) and then CAP execute it. That is way I need to convert a string to a expression
I want to have ultimate flexibility in my YAML description and not limited in a few expression implemented internal in CAP
The tutorial page on the GitHub may give you an idea how CAP is going to work: CAP/TUTORIAL.md at main · ArashLab/CAP · GitHub
But the code has been changed significantly since then and is subject to more changes.
Also it is pretty a mess and incomplete at the moment until I make v0.2.0