[#6] make callbacks more user friendly

README.md

@@ -335,11 +335,11 @@ as client side code. An example from the
     "pod.babashka.filewatcher"
     'pod.babashka.filewatcher/watch*
     [path opts]
-    {:handlers {:success (fn [{:keys [:value]}] (cb value))
+    {:handlers {:success cb
                 :error (fn [{:keys [:ex-message :ex-data]}]
                          (binding [*out* *err*]
                            (println "ERROR:" ex-message)))
-                :done (fn [_])}})
+                :done (fn [])}})
    nil))
 ```
 
@@ -358,9 +358,9 @@ The return value of `babashka.pods/invoke` is a map containing `:result`. When
 not using callbacks, this is the return value from the pod var invocation. When
 using callbacks, this value is undefined.
 
-The callback `:success` is called with a map containing:
-
-- `:value`: a return value from the pod var
+The callback `:success` is called with a map containing a return value from the
+pod invocation. The pod can potentially return multiple values. The callback
+will be called with every value individually.
 
 The callback `:error` is called in case the pod sends an error, a map
 containing:
@@ -372,9 +372,9 @@ containing:
 If desired, `:ex-message` and `:ex-data` can be reified into a
 `java.lang.Exception` using `ex-info`.
 
-The callback `:done` is called with one argument, a map. This callback can be
-used to determine if the pod is done sending values, in case it wants to send
-multiple. The callback is only called if no errors were sent by the pod.
+The callback `:done` is a 0-arg function. This callback can be used to determine
+if the pod is done sending values, in case it wants to send multiple. The
+callback is only called if no errors were sent by the pod.
 
 In the above example the wrapper function calls the pod identified by
 `"pod.babashka.filewatcher"`. It calls the var

src/babashka/pods/impl.clj

@@ -81,7 +81,7 @@
                 (cond promise?
                       (deliver chan (if error? exception value))
                       (and (not error?) success-handler)
-                      (success-handler {:value value})
+                      (success-handler value)
                       (and error? error-handler)
                       (error-handler {:ex-message ex-message
                                       :ex-data ex-data})))
@@ -89,7 +89,7 @@
                 (when promise?
                   (deliver chan nil))
                 (when done-handler
-                  (done-handler {})))
+                  (done-handler)))
               (when out
                 (binding [*out* out-stream]
                   (println out)))

test-resources/test_program.clj

@@ -5,9 +5,9 @@
 (def stream-results (atom []))
 (def done-prom (promise))
 (pods/invoke "pod.test-pod" 'pod.test-pod/range-stream [1 10]
-             {:handlers {:success (fn [{:keys [:value]}]
+             {:handlers {:success (fn [value]
                                     (swap! stream-results conj value))
-                         :done (fn [_]
+                         :done (fn []
                                  (deliver done-prom :ok))}})
 @done-prom
 
@@ -24,7 +24,7 @@
 (def callback-result (promise))
 (pods/invoke "pod.test-pod" 'pod.test-pod/add-sync [1 2]
              {:handlers {:success
-                         (fn [{:keys [:value]}]
+                         (fn [value]
                            (deliver callback-result value))}})
 
 (def error-result (promise))