I’m a fan of the Hexagonal Architecture / Ports-and-Adapters pattern.
I’m used to implementing it with defprotocol and defrecord in
Clojure, but this approach has drawbacks when you add Clojure Spec to
the mix. I explored (very lightly!) three approaches:
- The Protocol + Record way I’m used to
- Multimethods
- Simple map of functions
The TL;DR is that the last one plays much better with Spec than the other two approaches.
Specifically, if I made changes to the uses namespace and
re-evaluated that into my REPL, I struggled to get my demo to work
without launching a fresh repl. (Sometimes I could make it work with a
carefully ordered re-eval of the other files, but not always.) The
map-of-functions approach was much more forgiving.
Copyright © 2022 Stig Brautaset
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