Data Macros are a thing

Who knows if the term Data Macro will stick but it makes sense.

A Clojure macro expands code (data) so anything that expands data can be called a macro as well.

But which expansion mechanism is best? What does best mean?

Let's call the expansion a data transform. Here's how we'll evaluate:

• Transform Readability
• Transform Safety i.e. shape conformance checks (cough...types)
• Transform Versatility i.e. supports many input and output shapes

Note: not rating data/DSL readability because that is part of a specific app design, not a generalised design or idea.