Extensible Data Notation (edn) is a cross-platform, cross-language data format. It is basically a standardization of Clojure’s literal data syntax. It has most of the data types you’re used to using in Clojure (maps, keywords, sets, etc). In addition, it lets you define new semantic types by tagging other literals with symbols. For instance, dates are represented with strings (in ISO format) tagged with the symbol
In this lesson, we explore how to read and write edn, including custom data types.