Field accessors as functions in clojure?

Question

Is there a way to convert field feature accessors? I was very surprised when I tried to do this.

(map .x [o1 o2])

but instead had to do this

(defn x [o] (.x o))
(map x [o1 o2])

which seems overkill. Is there a way to create this function for you?

+3

clojure

Cristian Garcia 24 Sep 14 at 16:50

source to share

2 answers

Use anonymous fn

(map #(.x %) [o1 o2])
(map (fn [o] (.x o)) [o1 o2])

Or memfn - I was reading anonymous fn

. I will try to find the article.

(map (memfn x) [o1 o2])

Edit : Stu Halloway has this one to say aboutmemfn

+7

Kyle 24 Sep 14 at 16:52

source to share

Thumbnail · Accepted Answer · 2014-09-25T13:31:13+0000

You can write your own macro to create an anonymous function:

(defmacro field [m] `(fn [x#] (. x# ~m)))

Then, for example,

((field x) (java.awt.Point. 3 5))
;3