Add another select example.

examples/select2.janet

@@ -0,0 +1,37 @@
+###
+### examples/select2.janet
+###
+### Mix reads and writes in select.
+###
+
+(def c1 (ev/chan 40))
+(def c2 (ev/chan 40))
+(def c3 (ev/chan 40))
+(def c4 (ev/chan 40))
+
+(def c5 (ev/chan 4))
+
+(defn worker
+  [c n x]
+  (forever
+    (ev/sleep n)
+    (ev/give c x)))
+
+(defn writer-worker
+  [c]
+  (forever
+    (ev/sleep 0.2)
+    (print "writing " (ev/take c))))
+
+(ev/call worker c1 1 :item1)
+(ev/sleep 0.2)
+(ev/call worker c2 1 :item2)
+(ev/sleep 0.1)
+(ev/call worker c3 1 :item3)
+(ev/sleep 0.2)
+(ev/call worker c4 1 :item4)
+(ev/sleep 0.1)
+(ev/call worker c4 1 :item5)
+(ev/call writer-worker c5)
+
+(forever (pp (ev/rselect c1 c2 c3 c4 [c5 :thing])))