> I want to learn Idris or any other purely functional programming language one day to the point where I would be able to read any program, but most programs written in those languages are so terse and abstract, that I constantly find myself lost in them.
Elm is purely functional and shares your design sensibilities on this.
It is less terse (by design) than other purely functional languages and (as of the upcoming release) does not support user-defined operators.
I know plenty of folks who got into Elm and then found Haskell and Idris much easier to approach, so it can unlock further learning too!