IllegalArgumentException Key must be integer error in Clojure

Question

Am getting the subject error when trying to do a simple thread macro.

Keyword defines

(def entityType (keyword "name"))
(def entityURI (keyword "uri"))

I have the following 'lazy' sequence:

(def m1
    (({:uri "...#OWLClass_82601afd_b43d_43b4_94fe_2836f40009ca", :name "foo"} 
    {:uri "...#OWLClass_8c6759f0_a165_4a09_a9d8_2603bb106fc6", :name "bar"}))

Here is the REPL thread:

(->> (first m1)
     (map (fn [rec] (rec entityType))))

And the resulting error:

IllegalArgumentException Key must be integer  clojure.lang.APersistentVector.invoke (APersistentVector.java:265)

Anyone with any insight?

Actually you are supposed to get NullPointerException once you meet the definition of m1 — Chiron
– Chiron, Commented Jan 29, 2014 at 14:21

ponzao · Accepted Answer · 2014-01-29 14:45:24Z

3

Based on your code I am guessing you want m1 to be declared like this:

(def m1
  (list (list {:uri "...#OWLClass_82601afd_b43d_43b4_94fe_2836f40009ca", :name "foo"} 
              {:uri "...#OWLClass_8c6759f0_a165_4a09_a9d8_2603bb106fc6", :name "bar"})))

Thus:

(->> (first m1)
     (map (fn [rec] (rec entityType))))
;=> ("foo" "bar")

Is this what you were after?

EDIT:

Based on your comment I've understood that the structure of m1 is flatter, like this:

(def m1
  (list {:uri "...#OWLClass_82601afd_b43d_43b4_94fe_2836f40009ca", :name "foo"} 
        {:uri "...#OWLClass_8c6759f0_a165_4a09_a9d8_2603bb106fc6", :name "bar"}))

Based on this you can just do (map (fn [rec] (rec entityType)) m1) and drop the ->>.

edited Jan 29, 2014 at 14:45

answered Jan 29, 2014 at 14:21

ponzao

21k3 gold badges44 silver badges58 bronze badges

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

4 Comments

Frank C. Over a year ago

m1 (which is actually generated from another call) is (type m1) clojure.lang.LazySeq and (type (first m1)) is clojure.lang.PersistentArrayMap. If I write (->> (first m1) (map (fn [rec] (type rec))))… Frank: there are other 'keys' that I didn't show in the question/post. I get: (clojure.lang.MapEntry clojure.lang.MapEntry clojure.lang.MapEntry clojure.lang.MapEntry clojure.lang.MapEntry clojure.lang.MapEntry clojure.lang.MapEntry)

ponzao Over a year ago

In that case instead of a ->> you can just use (map (fn [rec] (rec entityType)) m1).

Frank C. Over a year ago

but I'm building up the thread to process the entire list (m1) so I need the macro.

ponzao Over a year ago

Then just do (->> m1 (map (fn [rec] (rec entityType)))).

Benjamin McFerren · Accepted Answer · 2018-08-24 01:05:27Z

0

For those who wind up on this post after searching this error string, be careful you are not accidentlly trying to assoc a (keyword ...) to a vector:'

(def foo [])

(assoc-in foo [:aaa (keyword "b-bb")] ["obj"] )

answered Aug 24, 2018 at 1:05

Benjamin McFerren

8725 gold badges21 silver badges38 bronze badges

Collectives™ on Stack Overflow

IllegalArgumentException Key must be integer error in Clojure

2 Answers 2

4 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

4 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related