Pretty cool project, like a functional reinterpretation of dependency injection frameworks. The basic idea behind dependency injection is to make all dependencies for each unit explicit and externally supplied.

DI frameworks then build upon the pattern offering a declarative DSL to declare dependencies and wiring. They also offer a selection of alternatives to build dependent objects (e.g. build a fresh one when needed or supply a global instance for every dependee) and a smidgen of generic functionality via impersonation (e.g. monitoring, logging, timing, transaction acquisition/release).

Interesting that untyped functional programming and macros allow for a lighter expression of the same basic idea.

Also interesting that maps of functions are a fundamental part of the solution. There are definitions of object-orientation that amount to basically records-of-lambdas. I've long thought that there is a lot to gain by using this basic abstraction as it naturally provides seams for testing/observability/auditing/etc.