First function in tutorial fails: IllegalStateException - Attempting to call unbound function

[Aniruddh Joshi]

Hi ,

I am going through the Try clojure tutorial.
It has a hello world function -

(defn square[x] (* x x))

When i hit above command on the

clojure>

prompt , I get below-

#'sandbox24027/square

which looks like a success message.
But when I call it-

 (square[9]) 

I get below exception -

java.lang.IllegalStateException- Attempting to call unbound function - 'sandbox24027/square

Looks like it can read the compiled function but can not call it. Any idea?

Same has happened with other functions I tried to create.

[Chas Emerick]

You're calling the square function slightly wrong (you're passing a vector containing a number, and not a number; watch the brackets), but I actually get a different error than you (java.lang.ClassCastException: clojure.lang.PersistentVector cannot be cast to java.lang.Number).

It sounds like your TryClj session might be hosed, or the site was having issues at the time? Maybe try again.

FWIW, here's a session copy/pasted from TryClj:

Clojure> (defn square [x] (* x x))
#'sandbox25629/square
Clojure> (square 5)
25
Clojure> (square [5])
java.lang.ClassCastException: clojure.lang.PersistentVector cannot be cast to java.lang.Number

--
(coauthor of Clojure Programming from O'Reilly; creator of Clojure Atlas)

[Aniruddh Joshi]

I get the same error even after removing the square brackets -

Clojure> (def square (fn [x] (* x x)))
#'sandbox24027/square
Clojure> (square 45)
java.lang.IllegalStateException: Attempting to call unbound fn: #'sandbox24027/square
Clojure> (square 3)
java.lang.IllegalStateException: Attempting to call unbound fn: #'sandbox24027/square

let me try a new session.. maybe I've tried craeting the same function multiple times.

[Aniruddh Joshi]

With a new browser session I am on the same page as you
Probably my sandbox went stale by trying multiple things on the same function.
Thanks!

[Aniruddh Joshi]

Reproduced the problem, check below-

Clojure> (defn fuzz [x] ( * 1.23 ( / x 7 )) )
#'sandbox24027/fuzz
Clojure> fuzz 8
#<sandbox24027$fuzz sandbox24027$fuzz@3a790aaa>
Clojure> (fuzz 8)
java.lang.IllegalStateException: Attempting to call unbound fn: #'sandbox24027/fuzz

Which means if I call it incorrectly once, it goes for a toss?

What does

Clojure> fuzz 8

do ?

[Sean Corfield]

Aniruddh Joshi wrote:What does

Clojure> fuzz 8

do ?

It evaluates fuzz then it evaluates 8. The former will either resolve to a symbol and it's internal name will be displayed (that sandbox...$fuzz... string you saw) or an exception if it is unknown. The latter will resolve to the value 8 which will be displayed.

[Palak Mathur]

Aniruddh Joshi wrote:Reproduced the problem, check below-

Clojure> (defn fuzz [x] ( * 1.23 ( / x 7 )) )
#'sandbox24027/fuzz
Clojure> fuzz 8
#<sandbox24027$fuzz sandbox24027$fuzz@3a790aaa>
Clojure> (fuzz 8)
java.lang.IllegalStateException: Attempting to call unbound fn: #'sandbox24027/fuzz

Which means if I call it incorrectly once, it goes for a toss?

What does

Clojure> fuzz 8

do ?

I didnt get any exceptions. See below:-

Clojure> (defn fuzz [x] ( * 1.23 ( / x 7 )) )
#'sandbox86125/fuzz
Clojure> (fuzz 8)
1.405714285714286
Clojure> fuzz 8
#<sandbox86125$fuzz sandbox86125$fuzz@225b957e>
Clojure> 

[Aniruddh Joshi]

@Palak- try reversing the order of your last 2 commands.

[Palak Mathur]

Aniruddh Joshi wrote:@Palak- try reversing the order of your last 2 commands.

It worked:-

Enter some Clojure code to be evaluated.
Clojure> (defn fuzz [x] ( * 1.23 ( / x 7 )) )  
#'sandbox1546/fuzz
Clojure> fuzz 8
#<sandbox1546$fuzz sandbox1546$fuzz@3dcf2ef6>
Clojure> (fuzz 8)
1.405714285714286
Clojure>  

[Palak Mathur]

What exactly do you think the issue might be? I didn't receive any error.

[Aniruddh Joshi]

Maybe like Chas said, something wrong with tryclj.
Will try it again when I get some time.