Question

We usually use builder pattern in java, like this:

UserBuilder userBuilder = new UserBuilder();
User John = userBuiler.setName("John")
                      .setPassword("1234")
                      .isVip(true)
                      .visableByPublic(false)
                      .build();

Some of the attributes have default value, and some haven’t.

Passing attributes in a map may be a solution, but it makes the argument really longer:

(def john (make-user {:name "John" :pass "1234" :vip true :visible false}))

So, my question is, is there a elegant way to achieve this?

Answer 1

If you want to construct some clojure structure, you can use destructuring pattern in function arguments. You will then achieve the similar thing you have already wrote.

(defn make-user [& {:keys [name pass vip visible]}]
  ; Here name, pass, vip and visible are regular variables
  ; Do what you want with them
)

(def user (make-user :name "Name" :pass "Pass" :vip false :visible true))

I doubt that you can do something in less code than this.

If you want to construct Java object (using its setters), you can use the approach Nicolas suggested.