lua: require/package via package.preload +5 tests

lib/lua/runtime.sx

@@ -1315,3 +1315,28 @@
 (dict-set! os "rename" lua-os-rename)
 (dict-set! os "tmpname" lua-os-tmpname)
 (dict-set! os "execute" lua-os-execute)
+
+;; ── package / require ─────────────────────────────────────────
+(define package {})
+(define __package-loaded {})
+(define __package-preload {})
+
+(dict-set! package "loaded" __package-loaded)
+(dict-set! package "preload" __package-preload)
+(dict-set! package "path" "?;?.lua")
+
+(define
+  lua-require
+  (fn (name)
+    (cond
+      ((has-key? __package-loaded name) (get __package-loaded name))
+      ((has-key? __package-preload name)
+        (let ((loader (get __package-preload name)))
+          (let ((m (lua-call loader name)))
+            (let ((result (if (= m nil) true m)))
+              (begin
+                (dict-set! __package-loaded name result)
+                result)))))
+      (else (error (str "lua: module '" name "' not found"))))))
+
+(define require lua-require)