Varnishable

Varnishable is a term used in programming, particularly in the context of the Clojure programming language. It refers to data structures that can be efficiently converted into a "vanilla" or simpler representation. This conversion process is often employed for serialization, interop with other languages or systems, or when a simpler, less optimized representation is sufficient. The idea behind varnishable is to avoid the overhead associated with complex, feature-rich data structures when only their fundamental data content is needed.

In Clojure, common varnishable types include persistent maps, vectors, and sets. When these are converted to a varnishable form, they might be transformed into standard Java collections like `HashMap`, `ArrayList`, or `HashSet`, or even simpler primitive data types if applicable. This transformation allows for easier transmission over networks, storage in databases, or use in environments that do not natively support Clojure's persistent data structures. The term emphasizes the ability of a data structure to shed its specialized optimizations and become a more universally understood representation. It's a concept that promotes efficient data handling and interoperability.

---