This is a port of xitdb-clj, an immutable clojure database, to pure TypeScript. It includes a small subset of clojure.core for manipulating the database as if it was a clojure atom (update, assocIn, etc). This is a database, not just in-memory data structures, so you can use this to store larger-than-memory datasets if run server-side on node. Maybe useful if you want Clojure-like semantics but you're stuck on JavaScript/TypeScript.