:inject in process fn-map is now :introduce, more accurate and avoids confusion with flow/inject

Author: richhickey

src/main/clojure/clojure/core/async/flow.clj

@@ -83,7 +83,7 @@
   
   ::flow/report-chan - a core.async chan for reading.'ping' reponses
   will show up here, as will any explicit ::flow/report outputs
-  from :transform/:inject
+  from :transform/:introduce
   
   ::flow/error-chan - a core.async chan for reading. Any (and only)
   exceptions thrown anywhere on any thread inside a flow will appear
@@ -138,7 +138,7 @@
   "Given a map of functions (described below), returns a launcher that
   creates a process compliant with the process protocol (see the
   spi/ProcLauncher doc). The possible entries for process-impl-map
-  are :describe, :init, :transition, :transform and :inject. This is
+  are :describe, :init, :transition, :transform and :introduce. This is
   the core facility for defining the logic for processes via ordinary
   functions.
 
@@ -171,7 +171,7 @@
   process will no longer be used following that. See the SPI for
   details. state' will be the state supplied to subsequent calls.
 
-  Exactly one of either :transform or :inject are required.
+  Exactly one of either :transform or :introduce are required.
 
   :transform - (state in-name msg) -> [state' output]
   where output is a map of outid->[msgs*]
@@ -184,19 +184,19 @@
   may never be nil (per core.async channels). state' will be the state
   supplied to subsequent calls.
 
-  :inject - (state) -> [state' output]
+  :introduce - (state) -> [state' output]
   where output is a map of outid->[msgs*], per :transform
  
-  The inject fn is used for sources - proc-impls that inject new data
+  The introduce fn is used for sources - proc-impls that introduce new data
   into the flow by doing I/O with something external to the flow and
-  feeding that data to its outputs. A proc-impl specifying :inject may not
+  feeding that data to its outputs. A proc-impl specifying :introduce may not
   specify any :ins in its descriptor, as none but the ::flow/control channel
-  will be read. Instead, inject will be called every time through the
+  will be read. Instead, introduce will be called every time through the
   process loop, and will presumably do blocking or paced I/O to get
   new data to return via its outputs. If it does blocking I/O it
   should do so with a timeout so it can regularly return to the
   process loop which can then look for control messages - it's fine
-  for inject to return with no output. Do not spin poll in the inject
+  for introduce to return with no output. Do not spin poll in the introduce
   fn.
 
   proc accepts an option map with keys:
@@ -205,13 +205,13 @@
                 will be used when getting the return from the future - see below
 
   The :compute context is not allowed for proc impls that
-  provide :inject (as I/O is presumed).
+  provide :introduce (as I/O is presumed).
 
   In the :exec context of :mixed or :io, this dictates the type of
   thread in which the process loop will run, _including its calls to
-  transform/inject_. 
+  transform/introduce_. 
 
-  When :io is specified transform/inject should not do extensive computation.
+  When :io is specified transform/introduce should not do extensive computation.
 
   When :compute is specified (only allowed for :transform), each call
   to transform will be run in a separate thread. The process loop will

src/main/clojure/clojure/core/async/flow/impl.clj

@@ -202,7 +202,7 @@
                 (loop [nstatus nstatus, nstate nstate, msgs (seq msgs)]
                   (if (or (nil? msgs) (= nstatus :exit))
                     [nstatus nstate]
-                    (let [m (if-some [m (first msgs)] m (throw "messages must be non-nil"))
+                    (let [m (if-some [m (first msgs)] m (throw (Exception.  "messages must be non-nil")))
                           [v c] (async/alts!!
                                  [control [outc m]]
                                  :priority true)]
@@ -216,10 +216,10 @@
 
 (defn proc
   "see lib ns for docs"
-  [{:keys [describe init transition transform inject] :as impl} {:keys [exec compute-timeout-ms]}]
+  [{:keys [describe init transition transform introduce] :as impl} {:keys [exec compute-timeout-ms]}]
   ;;validate the preconditions
-  (assert (= 1 (count (keep identity [transform inject]))) "must provide exactly one of :transform or :inject")
-  (assert (not (and inject (= exec :compute))) "can't specify :inject and :compute")
+  (assert (= 1 (count (keep identity [transform introduce]))) "must provide exactly one of :transform or :introduce")
+  (assert (not (and introduce (= exec :compute))) "can't specify :introduce and :compute")
   (reify
     clojure.core.protocols/Datafiable
     (datafy [_]
@@ -228,7 +228,7 @@
     spi/ProcLauncher
     (describe [_]
       (let [{:keys [params ins] :as desc} (describe)]
-        (assert (not (and ins inject)) "can't specify :ins when :inject")
+        (assert (not (and ins introduce)) "can't specify :ins when :introduce")
         (assert (or (not params) init) "must have :init if :params")
         desc))
     (start [_ {:keys [pid args ins outs resolver]}]
@@ -261,7 +261,7 @@
                          ;;:running
                          (let [[msg c] (if transform
                                          (async/alts!! read-chans :priority true)
-                                         ;;inject
+                                         ;;introduce
                                          (when-let [msg (async/poll! control)]
                                            [msg control]))
                                cid (io-id c)]
@@ -272,7 +272,7 @@
                              (try
                                (let [[nstate outputs] (if transform
                                                         (transform state cid msg)
-                                                        (inject state))
+                                                        (introduce state))
                                      [nstatus nstate]
                                      (send-outputs status nstate outputs outs resolver control handle-command transition)]
                                  [nstatus nstate (inc count)])