Last week I took a look at three data specification libariers in Clojure: Schema, Spec, and Malli. This week, let’s talk about the essential features of these libraries. Data specification language. This is the foundation of every data specification library: a way to describe the data with a schema. You could use an existing language such as JSON Schema, but in practice that’s clunky and everybody develops their own language. ;; Let's model users. We want to know the user's name and the y...