erlang: spawn/1 + self/0 + is_pid (+13 tests)

lib/erlang/runtime.sx

@@ -208,3 +208,68 @@
 (define
   er-proc-mailbox-size
   (fn (pid) (er-q-len (er-proc-field pid :mailbox))))
+
+;; ── process BIFs ────────────────────────────────────────────────
+(define
+  er-bif-is-pid
+  (fn (vs) (er-bool (er-pid? (er-bif-arg1 vs "is_pid")))))
+
+(define
+  er-bif-self
+  (fn
+    (vs)
+    (if
+      (not (= (len vs) 0))
+      (error "Erlang: self/0: arity")
+      (let
+        ((pid (er-sched-current-pid)))
+        (if
+          (= pid nil)
+          (error "Erlang: self/0: no current process")
+          pid)))))
+
+(define
+  er-bif-spawn
+  (fn
+    (vs)
+    (cond
+      (= (len vs) 1) (er-spawn-fun (nth vs 0))
+      (= (len vs) 3) (error
+        "Erlang: spawn/3: module-based spawn deferred to Phase 5 (modules)")
+      :else (error "Erlang: spawn: wrong arity"))))
+
+(define
+  er-spawn-fun
+  (fn
+    (fv)
+    (if
+      (not (er-fun? fv))
+      (error "Erlang: spawn/1: not a fun")
+      (let
+        ((proc (er-proc-new! (er-env-new))))
+        (dict-set! proc :initial-fun fv)
+        (get proc :pid)))))
+
+;; ── scheduler loop ──────────────────────────────────────────────
+;; Drain all runnable processes to completion. Synchronous — each
+;; spawned process runs its :initial-fun front-to-back with no yielding.
+;; receive-driven suspension arrives in the next roadmap step.
+(define
+  er-sched-drain!
+  (fn
+    ()
+    (let
+      ((pid (er-sched-next-runnable!)))
+      (when
+        (not (= pid nil))
+        (er-sched-set-current! pid)
+        (er-proc-set! pid :state "running")
+        (let
+          ((fv (er-proc-field pid :initial-fun)))
+          (when
+            (not (= fv nil))
+            (er-apply-fun fv (list))))
+        (er-proc-set! pid :state "dead")
+        (er-proc-set! pid :exit-reason (er-mk-atom "normal"))
+        (er-sched-set-current! nil)
+        (er-sched-drain!)))))