erlang: receive...after Ms timeout clause (+9 tests)

lib/erlang/transpile.sx

@@ -954,8 +954,12 @@
   (fn
     (node env)
     (let
-      ((pid (er-sched-current-pid)))
-      (er-eval-receive-loop node pid env))))
+      ((pid (er-sched-current-pid))
+        (after-node (get node :after-ms)))
+      (if
+        (= after-node nil)
+        (er-eval-receive-loop node pid env)
+        (er-eval-receive-with-after node pid env after-node)))))
 
 (define
   er-eval-receive-loop
@@ -975,6 +979,57 @@
               er-suspend-marker))
           (er-eval-receive-loop node pid env))))))
 
+(define
+  er-eval-receive-with-after
+  (fn
+    (node pid env after-node)
+    (let
+      ((ms (er-eval-expr after-node env)))
+      (cond
+        (and (er-atom? ms) (= (get ms :name) "infinity"))
+        (er-eval-receive-loop node pid env)
+        (= ms 0) (er-eval-receive-poll node pid env)
+        :else (er-eval-receive-timed node pid env)))))
+
+;; after 0 — poll once; on no match, run the after-body immediately.
+(define
+  er-eval-receive-poll
+  (fn
+    (node pid env)
+    (let
+      ((r (er-try-receive (get node :clauses) pid env)))
+      (if
+        (get r :matched)
+        (get r :value)
+        (er-eval-body (get node :after-body) env)))))
+
+;; after Ms — suspend; on resume check :timed-out. When the scheduler
+;; runs out of other work it fires one pending timeout per round.
+(define
+  er-eval-receive-timed
+  (fn
+    (node pid env)
+    (let
+      ((r (er-try-receive (get node :clauses) pid env)))
+      (if
+        (get r :matched)
+        (get r :value)
+        (do
+          (er-proc-set! pid :has-timeout true)
+          (shift
+            k
+            (do
+              (er-proc-set! pid :continuation k)
+              (er-proc-set! pid :state "waiting")
+              er-suspend-marker))
+          (if
+            (er-proc-field pid :timed-out)
+            (do
+              (er-proc-set! pid :timed-out false)
+              (er-proc-set! pid :has-timeout false)
+              (er-eval-body (get node :after-body) env))
+            (er-eval-receive-timed node pid env)))))))
+
 ;; Scan mailbox in arrival order. For each msg, try every clause.
 ;; On first match: remove that msg from mailbox and return body value.
 (define