5 files changed, 35 insertions, 56 deletions

diff --git a/src/intercopycontext.cpp b/src/intercopycontext.cpp
index 0301382..6ebbbb0 100644
--- a/src/intercopycontext.cpp
+++ b/src/intercopycontext.cpp
@@ -28,6 +28,7 @@ THE SOFTWARE.
 
 #include "debugspew.h"
 #include "deep.h"
+#include "keeper.h"
 #include "universe.h"
 
 // #################################################################################################
@@ -887,7 +888,12 @@ void InterCopyContext::inter_copy_keyvaluepair() const
 {
     void* const _p{ lua_touserdata(L1, L1_i) };
     DEBUGSPEW_CODE(fprintf(stderr, "%p\n", _p));
-    lua_pushlightuserdata(L2, _p);
+    // when copying a nil sentinel in a non-keeper, write a nil in the destination
+    if (mode != LookupMode::ToKeeper && kNilSentinel.equals(L1, L1_i)) {
+        lua_pushnil(L2);
+    } else {
+        lua_pushlightuserdata(L2, _p);
+    }
     return true;
 }
 
@@ -898,7 +904,12 @@ void InterCopyContext::inter_copy_keyvaluepair() const
     if (vt == VT::KEY) {
         return false;
     }
-    lua_pushnil(L2);
+    // when copying a nil in a keeper, write a nil sentinel in the destination
+    if (mode == LookupMode::ToKeeper) {
+        kNilSentinel.pushKey(L2);
+    } else {
+        lua_pushnil(L2);
+    }
     return true;
 }
 
diff --git a/src/keeper.cpp b/src/keeper.cpp
index 9bde2d5..b0ed062 100644
--- a/src/keeper.cpp
+++ b/src/keeper.cpp
@@ -569,26 +569,6 @@ void Linda::releaseKeeper(Keeper* K_) const
 
 // #################################################################################################
 
-void keeper_toggle_nil_sentinels(lua_State* L_, int start_, LookupMode const mode_)
-{
-    int const _n{ lua_gettop(L_) };
-    for (int _i = start_; _i <= _n; ++_i) {
-        if (mode_ == LookupMode::ToKeeper) {
-            if (lua_isnil(L_, _i)) {
-                kNilSentinel.pushKey(L_);
-                lua_replace(L_, _i);
-            }
-        } else {
-            if (kNilSentinel.equals(L_, _i)) {
-                lua_pushnil(L_);
-                lua_replace(L_, _i);
-            }
-        }
-    }
-}
-
-// #################################################################################################
-
 /*
  * Call a function ('func_name') in the keeper state, and pass on the returned
  * values to 'L'.
diff --git a/src/keeper.h b/src/keeper.h
index 62d9ec8..a902caa 100644
--- a/src/keeper.h
+++ b/src/keeper.h
@@ -40,7 +40,6 @@ struct Keepers
 // xxh64 of string "kNilSentinel" generated at https://www.pelock.com/products/hash-calculator
 static constexpr UniqueKey kNilSentinel{ 0xC457D4EDDB05B5E4ull, "lanes.null" };
 
-void keeper_toggle_nil_sentinels(lua_State* L_, int start_, LookupMode const mode_);
 [[nodiscard]] int keeper_push_linda_storage(Linda& linda_, DestState L_);
 
 using keeper_api_t = lua_CFunction;
diff --git a/src/linda.cpp b/src/linda.cpp
index 1916629..4bd4553 100644
--- a/src/linda.cpp
+++ b/src/linda.cpp
@@ -344,9 +344,6 @@ LUAG_FUNC(linda_get)
         if (_linda->cancelRequest == CancelRequest::None) {
             Keeper* const _K{ _linda->whichKeeper() };
             _pushed = keeper_call(_K->L, KEEPER_API(get), L_, _linda, 2);
-            if (_pushed.value_or(0) > 0) {
-                keeper_toggle_nil_sentinels(L_, lua_gettop(L_) - _pushed.value(), LookupMode::FromKeeper);
-            }
         } else { // linda is cancelled
             // do nothing and return lanes.cancel_error
             kCancelError.pushKey(L_);
@@ -492,10 +489,6 @@ LUAG_FUNC(linda_receive)
             }
             if (_pushed.value() > 0) {
                 LUA_ASSERT(L_, _pushed.value() >= _expected_pushed_min && _pushed.value() <= _expected_pushed_max);
-                // replace sentinels with real nils
-                keeper_toggle_nil_sentinels(L_, lua_gettop(L_) - _pushed.value(), LookupMode::FromKeeper);
-                // To be done from within the 'K' locking area
-                //
                 _linda->readHappened.notify_all();
                 break;
             }
@@ -589,8 +582,6 @@ LUAG_FUNC(linda_send)
             raise_luaL_error(L_, "no data to send");
         }
 
-        // convert nils to some special non-nil sentinel in sent values
-        keeper_toggle_nil_sentinels(L_, _key_i + 1, LookupMode::ToKeeper);
         bool _ret{ false };
         CancelRequest _cancel{ CancelRequest::None };
         KeeperCallResult _pushed;
@@ -701,10 +692,6 @@ LUAG_FUNC(linda_set)
         Keeper* const _K{ _linda->whichKeeper() };
         KeeperCallResult _pushed;
         if (_linda->cancelRequest == CancelRequest::None) {
-            if (_has_value) {
-                // convert nils to some special non-nil sentinel in sent values
-                keeper_toggle_nil_sentinels(L_, 3, LookupMode::ToKeeper);
-            }
             _pushed = keeper_call(_K->L, KEEPER_API(set), L_, _linda, 2);
             if (_pushed.has_value()) { // no error?
                 LUA_ASSERT(L_, _pushed.value() == 0 || _pushed.value() == 1);
diff --git a/tests/basic.lua b/tests/basic.lua
index d65728e..5a905e7 100644
--- a/tests/basic.lua
+++ b/tests/basic.lua
@@ -214,26 +214,27 @@ local chunk= function(linda)
     local function receive() return linda:receive("->") end
     local function send(...) linda:send("<-", ...) end
 
-    WR("Lane starts!\n")
+    WR("chunk ", "Lane starts!\n")
 
     local k,v
-    k,v=receive(); WR(v.." received\n"); assert(v==1)
-    k,v=receive(); WR(v.." received\n"); assert(v==2)
-    k,v=receive(); WR(v.." received\n"); assert(v==3)
-    k,v=receive(); WR(tostring(v).." received\n"); assert(v==nil)
+    k,v=receive(); WR("chunk ", v.." received (expecting 1)\n"); assert(v==1)
+    k,v=receive(); WR("chunk ", v.." received (expecting 2)\n"); assert(v==2)
+    k,v=receive(); WR("chunk ", v.." received  (expecting 3)\n"); assert(v==3)
+    k,v=receive(); WR("chunk ", tostring(v).." received  (expecting nil from __lanesignore)\n"); assert(v==nil) -- a table with __lanesignore was sent
+    k,v=receive(); WR("chunk ", tostring(v).." received (expecting nil)\n"); assert(v==nil)
 
-    send(1,2,3);              WR("1,2,3 sent\n")
-    send 'a';                 WR("'a' sent\n")
-    send(nil);                WR("nil sent\n")
-    send { 'a', 'b', 'c', d=10 }; WR("{'a','b','c',d=10} sent\n")
+    send(4,5,6);              WR("chunk ", "4,5,6 sent\n")
+    send 'aaa';               WR("chunk ", "'aaa' sent\n")
+    send(nil);                WR("chunk ", "nil sent\n")
+    send { 'a', 'b', 'c', d=10 }; WR("chunk ","{'a','b','c',d=10} sent\n")
 
-    k,v=receive(); WR(v.." received\n"); assert(v==4)
+    k,v=receive(); WR("chunk ", v.." received\n"); assert(v==4)
 
     local subT1 = { "subT1"}
     local subT2 = { "subT2"}
-    send { subT1, subT2, subT1, subT2}; WR("{ subT1, subT2, subT1, subT2} sent\n")
+    send { subT1, subT2, subT1, subT2}; WR("chunk ", "{ subT1, subT2, subT1, subT2} sent\n")
 
-    WR("Lane ends!\n")
+    WR("chunk ", "Lane ends!\n")
 end
 
 local linda = lanes_linda("communications")
@@ -248,15 +249,16 @@ local function RECEIVE() local k,v = linda:receive(1, "<-") return v end
 
 local comms_lane = lanes_gen("io", {gc_cb = gc_cb, name = "auto"}, chunk)(linda)     -- prepare & launch
 
-SEND(1);  WR("1 sent\n")
-SEND(2);  WR("2 sent\n")
-SEND(3);  WR("3 sent\n")
+SEND(1);  WR("main ", "1 sent\n")
+SEND(2);  WR("main ", "2 sent\n")
+SEND(3);  WR("main ", "3 sent\n")
+SEND(setmetatable({"should be ignored"},{__lanesignore=true})); WR("main ", "__lanesignore table sent\n")
 for i=1,100 do
     WR "."
     lanes.sleep(0.0001)
     assert(PEEK() == nil)    -- nothing coming in, yet
 end
-SEND(nil);  WR("\nnil sent\n")
+SEND(nil);  WR("\nmain ", "nil sent\n")
 
 local a,b,c = RECEIVE(), RECEIVE(), RECEIVE()
 
@@ -264,13 +266,13 @@ print("lane status: " .. comms_lane.status)
 if comms_lane.status == "error" then
     print(comms_lane:join())
 else
-    WR(a..", "..b..", "..c.." received\n")
+    WR("main ", tostring(a)..", "..tostring(b)..", "..tostring(c).." received\n")
 end
 
-assert(a==1 and b==2 and c==3)
+assert(a==4 and b==5 and c==6)
 
-local a = RECEIVE();   WR(a.." received\n")
-assert(a=='a')
+local aaa = RECEIVE(); WR("main ", aaa.." received\n")
+assert(aaa=='aaa')
 
 local null = RECEIVE();   WR(tostring(null).." received\n")
 assert(null==nil)