how so?

How can I transform a nested data structure lazily and recursively with Specter, e.g. to recursively build out a tree with children given some roots? I read through the docs on Using Specter Recursively, but it's not obvious to me how to "inject" new values into the data structure while navigating.

Re: spec, was just thinking in terms of validating arguments to the macros. Although, that’s already happening in some places via: https://github.com/redplanetlabs/specter/blob/master/src/clj/com/rpl/specter/impl.cljc#L379