In clojure, how can I undef a var from a namespace?

Question

In clojure I have lines like this that define default values:

(def *http-port* 8080)

I've now decided to formalize these kinds of values into a configuration unit and I would like to undefine the value *http-port* so that I can find the locations that still refer to this value and change them to use the new value. I'm doing a refactoring in other words by moving the value to a different location.

The way I've been doing this is to quit slime and try to restart the slime session. During maven's compile phase errors like these are picked up and I can find and fix one reference at a time. I then fix the error, wash rinse and repeat. This is obviously frustrating.

How would I do this while connected to a slime session?

score 43 · Accepted Answer · edited Feb 20 '17 at 16:59

43

If I understand you correctly, ns-unmap should do what you want:

user=> foo
java.lang.Exception: Unable to resolve symbol: foo in this context (NO_SOURCE_FILE:1)
user=> (def foo 1)
#'user/foo
user=> foo
1
user=> (ns-unmap (find-ns 'user) 'foo)
nil
user=> foo
java.lang.Exception: Unable to resolve symbol: foo in this context (NO_SOURCE_FILE:1)

edited Feb 20 '17 at 16:59

bfontaine

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answered Nov 17 '10 at 20:20

Hugh

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Other namespaces may still hold references to the value of 'foo. – Jürgen Hötzel Nov 17 '10 at 20:39
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@Jurgen this is true, but the solution is better than nothing – Pieter Breed Nov 17 '10 at 21:03
1

Just to remember: the default namespace is 'clojure.core – Felipe Jul 16 '14 at 01:46

In clojure, how can I undef a var from a namespace?

1 Answers1