Chris Oakasaki has a blog post about teaching functional programming using Ada. He says

Why, with excellent functional programming languages like Haskell or ML easily available, would I choose to do a functional programming project in Ada? (I CAN STILL HEAR YOU LAUGHING!) Partly because we use Ada in some courses at our institution, and I wanted a library that could help in teaching recursion to novices. But, honestly, mostly I just wanted to see if it could be done

The idea of crossing paradigms has been around awhile. SICP rather famously introduces object orientation by building it on top of Scheme.

What do you think about teaching or learning paradigm A in a language strongly oriented towards paradigm B? What's gained? What's lost?