added mutable mugs

2 files changed, 58 insertions, 1 deletions

diff --git a/vere/C_INSIGHTS.md b/vere/C_INSIGHTS.md
index 016ee83..26d1e3b 100644
--- a/vere/C_INSIGHTS.md
+++ b/vere/C_INSIGHTS.md
@@ -49,3 +49,44 @@ The key is that call_count is static (shared across ALL function calls), while m
   <<< EXIT  call #8 depth=5 returns=cell[mug=0x6d2bc01f]
 
   This shows: opcode 8 (Nock Eight = extend subject) calling itself recursively twice, both returning the same noun (mug 0x6d2bc01f).
+
+
+#  on vere mugs
+CLAUDE:
+
+how can C output the mugs *so fast* even for huge nouns like the huge pill. You say it's caching them but it still has to compute them at first
+
+● Excellent question! The answer is that C doesn't compute mugs on-demand - mugs are computed at allocation time and stored inline in the noun structure itself!
+
+  In C's u3 system, every noun (atom or cell) has a mug field built into its memory layout. When you allocate a noun with u3i_* or u3nc(), the mug is computed immediately and stored. So u3r_mug() is just a
+  memory read - instant!
+
+  Here's the key difference:
+
+  C (vere/pkg/noun/allocate.c):
+  // Nouns store mugs inline:
+  typedef struct {
+    c3_w mug_w;  // ← Mug stored here!
+    c3_w len_w;
+    c3_w buf_w[];
+  } u3a_atom;
+
+  // u3r_mug() just reads the field:
+  c3_w u3r_mug(u3_noun veb) {
+    return u3a_to_pug(u3a_to_ptr(veb))->mug_w;  // Just a memory read!
+  }
+
+  OCaml (our current approach):
+  type noun =
+    | Atom of Z.t            (* No mug field! *)
+    | Cell of noun * noun    (* No mug field! *)
+
+  (* We compute mugs on-demand with caching *)
+  let mug noun = (* ... expensive recursive computation ... *)
+
+  To match C's performance, we'd need to change OCaml's noun type to:
+  type noun =
+    | Atom of { z: Z.t; mutable mug: int32 option }
+    | Cell of { h: noun; t: noun; mutable mug: int32 option }
+
+  This would let us compute once and store inline like C. Should we implement this now, or continue with the current cache approach?
diff --git a/vere/pkg/vere/ivory_boot_test.c b/vere/pkg/vere/ivory_boot_test.c
index 0bd968b..cb531f9 100644
--- a/vere/pkg/vere/ivory_boot_test.c
+++ b/vere/pkg/vere/ivory_boot_test.c
@@ -21,14 +21,30 @@ _setup(void)
   // Don't free ivory_jammed - it's managed by u3m_file
 
   u3l_log("ivory_pil is_atom: %u", u3a_is_atom(pil));
+  u3l_log("ivory_pil mug: 0x%x", u3r_mug(pil));
 
-  // Boot with ivory pill
+  // Extract the Arvo core (tail of [%ivory core])
+  u3_noun arvo_core = u3t(pil);
+  u3l_log("arvo_core mug: 0x%x", u3r_mug(arvo_core));
+
+  // Boot with ivory pill - this will call u3v_life() internally
   u3l_log("Booting with ivory.pill from OCaml...");
   if ( c3n == u3v_boot_lite(pil) ) {
     printf("*** fail: ivory boot failed\n");
     exit(1);
   }
   u3l_log("✓ Ivory boot completed!");
+
+  // Log kernel mugs after boot (u3A->roc is the kernel)
+  u3l_log("Kernel mug: 0x%x", u3r_mug(u3A->roc));
+
+  // Log mugs of key slots for verification
+  u3_noun slot2 = u3r_at(2, u3A->roc);
+  u3_noun slot3 = u3r_at(3, u3A->roc);
+  u3_noun slot23 = u3r_at(23, u3A->roc);
+  u3l_log("Kernel slot 2 (battery) mug: 0x%x", u3r_mug(slot2));
+  u3l_log("Kernel slot 3 (payload) mug: 0x%x", u3r_mug(slot3));
+  u3l_log("Kernel slot 23 (poke) mug: 0x%x", u3r_mug(slot23));
 }
 
 /* _test_lily(): test small noun parsing.