Cosmetics in stdlib

stdlib/Lazy.lama

@@ -1,10 +1,21 @@
+-- Lazy.
+-- (C) Dmitry Boulytchev, JetBrains Research, St. Petersburg State University, 2020
+--
+-- Deferred computations.
+
 public fun makeLazy (f) {
   local value, set = false;
   
   fun () {
     if set
     then value
-    else set := true; value := f (); value
+    else
+      local c; -- need this temporary since in value := f () value would
+               -- create an intermediate managed pointer
+      set   := true;
+      c     := f ();
+      value := c;
+      c
     fi
   } 
 }