;; The expansion looks good, I'd say...

(case
    dir
  (#<EdgeDirection INOUT> nil)
  identity
  #<EdgeDirection OUT>
  (fn [i] (normal-edge? i))
  #<EdgeDirection IN>
  (fn [i] (not (normal-edge? i)))
  (throw (FunTGException. (format "Unknown direction %s" dir))))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defn- direction-matcher
  [dir]
  (case+ dir
         (EdgeDirection/INOUT nil) identity
         EdgeDirection/OUT         (fn [i] (normal-edge? i))
         EdgeDirection/IN          (fn [i] (not (normal-edge? i)))
         (throw (FunTGException.
                 ^String (format "Unknown direction %s" dir)))))

;; I get this compile error at the defn- above:

Unknown location:
  error: java.lang.RuntimeException: Can't embed object in code, maybe print-dup not defined: INOUT

core.clj:333:1:
  error: java.lang.RuntimeException: Can't embed object in code, maybe print-dup not defined: INOUT, compiling:(/home/horn/uni/repos/funtg/src/de/uni_koblenz/funtg/core.clj:333)

Compilation failed.