Clojure namespaces

Question

I want to split a big clojure-script into smaller ones. And it looks like this.

One:

(ns one
  (:use [two :only (show)]))

(def status "WORKING")

Two:

(ns two
  (:use [one :only (status)]))

(defn show [] (println status))

Result: Exception.

PS I understand that some some kind of recursive namespace constructing happens. I know only a sloppy half-solution, like defining without body before referncing to namespaces? Any suggestions?

kotarak · Accepted Answer · 2011-05-24 09:57:26Z

12

+1 for the answer of ponzao. To elaborate a bit more: Cyclic dependencies of namespaces are often a sign, that you didn't get your abstractions and/or APIs right. Either you "mix" layers or things should just be in one namespace, because the really belong together.

If you want to just split one namespace into several files, this is also possible.

name/space.clj:

(ns name.space)

(declare status)

(load "space_one")
(load "space_two")

name/space_one.clj:

(in-ns 'name.space)
(defn show [] (println status))

name/space_two.clj:

(in-ns 'name.space)
(def status "WORKING")

answered May 24, 2011 at 9:57

kotarak

17.3k2 gold badges53 silver badges41 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Alessandra Sierra Over a year ago

Clojure does not support cyclic dependencies between namespaces. You have to design to avoid it.

kotarak Over a year ago

@stuart-sierra Did I say something different?

ponzao · Accepted Answer · 2011-05-24 09:30:17Z

6

You are constructing a cyclic dependency between two components, are you sure this is what you want? Why not have a third namespace containing their common functions?

answered May 24, 2011 at 9:30

ponzao

21k3 gold badges44 silver badges58 bronze badges

1 Comment

Fedor Rusak Over a year ago

I don't want to over-engineer a simple project by making to many layers of abstractions and etc. One file keeps data, settings, and everything for processing. I wan't to use it as part of web-service. But for desktop-debugging i use simple visualization, which reads settings from main script, but gives a single function to show this thing on a screen. Thank you.

Collectives™ on Stack Overflow

Clojure namespaces

2 Answers 2

2 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related