Clojure Slime Configuration

Question

I have lein 1.7 with swank 1.4 plugin. Then, I start with no emacs configuration and install clojure-mode from marmalade, create a new project with lein, open up project.clj and then do M-x clojure-jack-in. Slime start just fine. Then I am entering this

; SLIME 20100404
user> (defn x[x]
          (let [y (* x 2)]
               (when (= y 2)
                 (throw (Exception. "hey")))
               y))
#'user/x
user> (x 2)
4
user> (x 1)

It throws me into a debugger, but it looks like it is not complete:

hey
  [Thrown class java.lang.Exception]

Restarts:
 0: [QUIT] Quit to the SLIME top level

Backtrace:
  0:       NO_SOURCE_FILE:1 user/x
      [No Locals]
  1:       NO_SOURCE_FILE:1 user/eval1854
      [No Locals]
  2:     Compiler.java:6465 clojure.lang.Compiler.eval
  3:     Compiler.java:6431 clojure.lang.Compiler.eval
  4:          core.clj:2795 clojure.core/eval
  5:           core.clj:532 swank.core/eval690[fn]
  6:       MultiFn.java:163 clojure.lang.MultiFn.invoke
  7:           basic.clj:54 swank.commands.basic/eval-region
  8:           basic.clj:44 swank.commands.basic/eval-region
  9:           basic.clj:78 swank.commands.basic/eval880[fn]
 --more--

Locals are not shown. No option to continue. I looked at the video: http://vimeo.com/23932914 How do I get to the same configuration of slime/emacs/clojure.

Answer 1

If I understand correctly, you want to see the locals at the point of the exception, however, I believe that your problem is that where the exception gets caught (after the exit of the x function) you've already moved out of the stackframe where the locals were defined.

For example, if you set a breakpoint....

user> (defn x [x]
        (let [y (* x 2)]
           (when (= 2 y)
             (swank.core/break) 
               (throw (Exception. "hey")))))
user> (x 1)

Then when you hit the break point and get the stack trace, the locals are available.

BREAK:
  [Thrown class java.lang.Exception]

Restarts:
 0: [QUIT] Quit to the SLIME top level
 1: [CONTINUE] Continue from breakpoint

Backtrace:
 0:       NO_SOURCE_FILE:1 user/x
      Locals:
        x = 1
        y = 2
 1:       NO_SOURCE_FILE:1 user/eval6821
 2:     Compiler.java:6465 clojure.lang.Compiler.eval
 3:     Compiler.java:6431 clojure.lang.Compiler.eval
 4:          core.clj:2795 clojure.core/eval
 5:           core.clj:532 swank.core/eval819[fn]
 6:       MultiFn.java:163 clojure.lang.MultiFn.invoke
 7:           basic.clj:54 swank.commands.basic/eval-region
 8:           basic.clj:44 swank.commands.basic/eval-region
 9:           basic.clj:78 swank.commands.basic/eval1009[fn]
 --more--

digging into the source for (swank.core/break), You can actually capture these local bindings yourself....

(defn x [x]
  (let [y (* x 2)]
    (when (= 2 y)
      (swank.core/local-bindings)
        (throw (Exception. "hey")))))

and you'll get the same stacktrace as above from the "hey" exception...

More details here