From 54bebfd260bc6d43a19b85c1006557479f03312b Mon Sep 17 00:00:00 2001
From: Jake Zerrer <him@jakezerrer.com>
Date: Sat, 1 Nov 2025 17:19:05 -0400
Subject: Add <bus and >bus functions

---
 src/midi.clj | 108 +++++++++++++++++++++++++++++++----------------------------
 1 file changed, 57 insertions(+), 51 deletions(-)

diff --git a/src/midi.clj b/src/midi.clj
index e330876..dabca7c 100644
--- a/src/midi.clj
+++ b/src/midi.clj
@@ -117,64 +117,70 @@
          (m/? (m/via m/blk (.close receiver)))
          (log/log! {:level :info, :id :midi/rx-closed}))))))
 
+(defn >bus
+  "Opens device named `name`.
+
+  Device will consume `flow`, a flow of Message objects."
+  [name flow]
+  (let [device
+        (first
+         (select-devices (get-all-midi-device-info)
+                         name false true))]
+    (with-device device
+      (fn [d]
+        (with-rx d flow)))))
+
+(defn <bus
+  "Opens device named `name`.
+
+  Calls `flow-handler` with a flow of midi messages.
+
+  `flow-handler` should return a flow."
+  [name flow-handler]
+  (let [device
+        (first
+         (select-devices (get-all-midi-device-info)
+                         name true false))]
+    (with-device device
+      (fn [d]
+        (with-tx d
+          (fn [f]
+            (m/reduce {} nil (flow-handler f))))))))
+
 (defn echo
-  [tx-device rx-device from-ch to-ch]
+  "Echo test."
+  [name from-ch to-ch]
   (m/sp
    (let [rv (m/rdv)]
      (m/?
       (m/join vector
-              (with-device tx-device
-                (fn [d]
-                  (println "Have tx device")
-                  (m/sp
-                   (m/?
-                    (with-tx d
-                      (fn [f]
-                        (m/sp
-                         (println "Have transmitter")
-                         (m/?
-                          (m/reduce prn nil
-                                    (m/ap
-                                     (let [v (m/?< f)]
-                                       (if  (= (class v) ShortMessage)
-                                         (let [v ^ShortMessage v]
-                                           (if (and (= from-ch (.getChannel v))
-                                                    (#{ShortMessage/NOTE_ON ShortMessage/NOTE_OFF} (.getCommand v)))
-                                             (let [new-msg (ShortMessage. (.getCommand v) to-ch
-                                                                          (.getData1 v)
-                                                                          (.getData2 v))]
-                                               (m/? (rv new-msg)))
-                                             (m/amb)))
-                                         (m/amb)))
-
-                                     (println "Value sent.")))))))))))
-              (with-device rx-device
-                (fn [d]
-                  (println "Have rx device")
-                  (m/sp
-                   (m/?
-                    (with-rx d
+              (<bus name
+                    (fn [f]
                       (m/ap
-                       (m/amb=
-                        (m/? m/never)
-                        (loop []
-                          (println "Echo rx awaiting value...")
-                          (m/amb
-                           (m/? rv)
-                           (recur)))))))))))))))
+                       (let [v (m/?< f)]
+                         (if  (= (class v) ShortMessage)
+                           (let [v ^ShortMessage v]
+                             (if (and (= from-ch (.getChannel v))
+                                      (#{ShortMessage/NOTE_ON ShortMessage/NOTE_OFF} (.getCommand v)))
+                               (let [new-msg (ShortMessage. (.getCommand v) to-ch
+                                                            (.getData1 v)
+                                                            (.getData2 v))]
+                                 (m/? (rv new-msg)))
+                               (m/amb)))
+                           (m/amb)))
+
+                       (log/log! {:level :debug, :id :midi/value-sent}))))
+              (>bus name
+                    (m/ap
+                     (m/amb=
+                      (m/? m/never)
+                      (loop []
+                        (log/log! {:level :debug, :id :midi/echo-rx-awaiting-value})
+                        (m/amb
+                         (m/? rv)
+                         (recur)))))))))))
 (def run
-  (m/sp
-   (let [txd
-         (first
-          (select-devices (get-all-midi-device-info)
-                          "CoreMIDI4J - IAC Bus" true false))
-
-         rxd
-         (first
-          (select-devices (get-all-midi-device-info)
-                          "CoreMIDI4J - IAC Bus" false true))]
-
-     (m/? (echo txd rxd 0 0)))))
+  (echo "CoreMIDI4J - IAC Bus" 0 0))
 
 ;; CoreMidiSource is TX Device
 ;; CoreMidiDestination is RX Device
-- 
cgit v1.2.3