tcl: Phase 3 OCaml primitives — file-read/write/append/exists?/glob + clock-seconds/milliseconds/format in sx_primitives.ml + unix dep; tcl-cmd-clock/file wired up; 337/337 green

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/tcl/runtime.sx

@@ -2865,10 +2865,12 @@
       (let
         ((sub (first args)) (rest-args (rest args)))
         (cond
-          ((equal? sub "seconds") (assoc interp :result "0"))
-          ((equal? sub "milliseconds") (assoc interp :result "0"))
+          ((equal? sub "seconds") (assoc interp :result (str (clock-seconds))))
+          ((equal? sub "milliseconds") (assoc interp :result (str (clock-milliseconds))))
           ((equal? sub "format")
-            (assoc interp :result "Thu Jan  1 00:00:00 UTC 1970"))
+            (assoc interp :result (clock-format
+              (floor (parse-int (first rest-args)))
+              (if (> (len rest-args) 1) (nth rest-args (- (len rest-args) 1)) "%a %b %e %H:%M:%S %Z %Y"))))
           ((equal? sub "scan") (assoc interp :result "0"))
           (else (error (str "clock: unknown subcommand \"" sub "\""))))))))
 
@@ -3151,7 +3153,7 @@
       (let
         ((sub (first args)) (rest-args (rest args)))
         (cond
-          ((equal? sub "exists") (assoc interp :result "0"))
+          ((equal? sub "exists") (assoc interp :result (if (file-exists? (first rest-args)) "1" "0")))
           ((equal? sub "join") (assoc interp :result (join "/" rest-args)))
           ((equal? sub "split")
             (assoc

lib/tcl/tests/coro.sx

@@ -95,15 +95,15 @@
       (get (run "proc g {} { yield }\ncoroutine cg g\ncg") :result)
       "")
 
-    ; --- clock seconds stub ---
+    ; --- clock seconds ---
     (ok "clock-seconds"
-      (get (run "clock seconds") :result)
-      "0")
+      (> (parse-int (get (run "clock seconds") :result)) 0)
+      true)
 
-    ; --- clock milliseconds stub ---
+    ; --- clock milliseconds ---
     (ok "clock-milliseconds"
-      (get (run "clock milliseconds") :result)
-      "0")
+      (> (parse-int (get (run "clock milliseconds") :result)) 0)
+      true)
 
     ; --- clock format stub ---
     (ok "clock-format"