From 8f97c5bf3c0afd9593db7e3a4c09e5f00863d9a2 Mon Sep 17 00:00:00 2001
From: Daniel Barlow <dan@telent.net>
Date: Tue, 12 Sep 2023 20:42:42 +0100
Subject: [PATCH] anoia service :events method behaves as iterator

---
 examples/acquire-wan-address.fnl | 12 ++++++------
 pkgs/anoia/svc.fnl               |  7 +++++++
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/examples/acquire-wan-address.fnl b/examples/acquire-wan-address.fnl
index faf20d0..07a1da0 100644
--- a/examples/acquire-wan-address.fnl
+++ b/examples/acquire-wan-address.fnl
@@ -31,14 +31,14 @@
     new-addresses))
 
 (fn run []
+  (var addresses [])
   (let [[state-directory wan-device] arg
         dir (svc.open state-directory)]
-    (var addresses [])
-    (while true
-      (while (not (dir:ready?)) (dir:wait))
-      (when (. bound-states (dir:output "state"))
+    (each [v (dir:events)]
+      ;; we don't handle unbound or stopped, where we should
+      ;; take the addresses away
+      (when (. bound-states (v:output "state"))
         (set addresses
-             (update-addresses wan-device addresses (dir:output "address"))))
-      (dir:wait))))
+             (update-addresses wan-device addresses (v:output "address")))))))
 
 { : update-addresses : changes : run }
diff --git a/pkgs/anoia/svc.fnl b/pkgs/anoia/svc.fnl
index 468434e..d980e7f 100644
--- a/pkgs/anoia/svc.fnl
+++ b/pkgs/anoia/svc.fnl
@@ -33,6 +33,12 @@
     unknown
     (error (.. "can't read " pathname " of kind \"" unknown.mode "\""))))
 
+(fn events [self]
+  (coroutine.wrap
+   #(while true
+      (while (not (self:ready?)) (self:wait))
+      (coroutine.yield self)
+      (self:wait))))
 
 (fn open [directory]
   (let [watcher (watch-fsevents directory)
@@ -44,6 +50,7 @@
      :output (fn [_ filename]
                (read-value (.. directory "/" filename)))
      :close #(watcher:close)
+     : events
      }))
 
 { : open }