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+1 vote
in Records and Types by

Coming from a RDF background I tend to use qualified keywords a lot when defining properties. However after looking at the Reitit HTTP router it appears that defrecord is really benefitial for performance. This often leads me to a choice between performance or clean data representation when designing software.

In order to avoid this dilemma, I think it would be nice if defrecord could support something similar to what is already done for map destructuring

(def m {:domain/id 14 :other/id "UV"})

(let [{:keys [domain/id]} m] id)
;;; ⤷ 14

We could have something like

(defrecord Employee [domain/id domain/full-name]
  (toString [_]
    (str "<< id: " id ", name: " full-name " >>")))

(def alyssa (->Employee 14 "Alyssa P. Hacker"))

(.toString alyssa)
;;; ⤷ "<< id: 14, name: Alyssa P. Hacker >>"

(:domain/id alyssa)
;;; ⤷ 14


  • the name part is bound in the record definition and is used as the Java internal class field
  • the fully qualified identifier is used when accessing/manipulating the record objects from its map-like interface.
  • collision in the field names would throw

I have implemented a prototype to demonstrate how it could be done in practice. I wonder if such extension has already been considered for clojure.core/defrecord and if there are some design/implementation issues that I am overlooking.

1 Answer

0 votes

There are many dimensions to consider for such an idea. Records already have a namespace in one aspect - the namespace of the record type. It seems potentially confusing to have a record type in one namespace with fields that are keys in different namespaces. In any case, I don't think this is something likely to receive attention soon.