[new] Add Signal printing methods

src/taoensso/telemere/impl.cljc

@@ -197,7 +197,23 @@
    location ns line column file,
    sample-rate, kind id level, ctx parent,
    data msg_ error run-form run-val,
-   end-instant run-nsecs extra-kvs])
+   end-instant run-nsecs extra-kvs]
+
+  Object (toString [sig] (str "#" `Signal (into {} sig))))
+
+(do     (enc/def-print-impl [sig Signal] (str "#" `Signal (pr-str (into {} sig)))))
+#?(:clj (enc/def-print-dup  [sig Signal] (str "#" `Signal (pr-str (into {} sig))))) ; NB intentionally verbose, to support extra keys
+
+(comment
+  (def s1 (with-signal (signal! {:level :info, :my-k1 :my-v1})))
+  (read-string (str    (assoc s1 :my-k2 :my-v2)))
+  (read-string (pr-str (assoc s1 :my-k2 :my-v2)))
+  (read-string (binding [*print-dup* true] (pr-str (assoc s1 :my-k2 :my-v2))))
+
+  (defrecord MyRec [x])
+  (read-string ; Non-verbose will fail on any extra keys
+    (binding [*print-dup* true, *verbose-defrecords* false]
+      (pr-str (assoc (MyRec. :x) :y :y)))))
 
 (deftype #_defrecord WrappedSignal
   ;; Internal type to implement `sigs/IFilterableSignal`,

test/taoensso/telemere_tests.cljc

@@ -215,7 +215,17 @@
         (is (= rv2 3))    (is (nil?    sv2))
         (is (= rv3 4))    (is (sm? sv3 {:m1 5 :m2 6}))
         (is (= rv4 true)) (is (=       sv4 "signal-value"))
-        (is (= @c  7)     "3x run + 4x middleware")]))])
+        (is (= @c  7)     "3x run + 4x middleware")]))
+
+   #?(:clj
+      (testing "Printing"
+        (let [sv1 (tel/with-signal (tel/signal! {:level :info, :run (+ 1 2), :my-k1 :my-v1}))
+              sv1 ; Ensure instants are printable
+              (-> sv1
+                (update :instant     enc/inst->udt)
+                (update :end-instant enc/inst->udt))]
+
+       [(is (= sv1 (read-string (pr-str sv1))))])))])
 
 (deftest _handlers
   ;; Basic handler tests are in Encore