Lift restriction on tables as table keys

As demonstrated by the unit tests, there is no problem with using a table as a table key

7 files changed, 54 insertions, 14 deletions

diff --git a/CHANGES b/CHANGES
index 17a79f7..5ebf0cd 100644
--- a/CHANGES
+++ b/CHANGES
@@ -57,9 +57,11 @@ CHANGE 2: BGe 05-Jun-25
             - linda:wake() can wake up threads waiting for a Linda without doing any I/O on it.
             - linda.status reads the cancel status of the Linda.
             - new function linda:collectgarbage() to force collection of all stale data in the associated keeper.
-            - Deep userdata are an acceptable key to send data into (for example, another linda).
+            - Deep userdata are an acceptable slot to send data into (for example, another linda).
+            - Tables can be used as table keys in transferred data.
         - Full userdata conversion:
             - __lanesconvert added.
+            - global configuration convert_fallback and convert_max_attempts added.
             - __lanesignore removed. Use __lanesconvert instead.
 
 CHANGE 1: BGe 9-Apr-24
diff --git a/docs/index.html b/docs/index.html
index eba39bb..452dcfa 100644
--- a/docs/index.html
+++ b/docs/index.html
@@ -1936,13 +1936,12 @@
 </p>
 
 <table border="1" bgcolor="#FFFFE0" cellpadding="10" style="width:50%"><tr><td><pre>
-        int luaopen_module(lua_State *L )
+        int luaopen_module(lua_State* L)
         {
                 static char been_here;  /* 0 by ANSI C */
 
                 // Calls to 'require' serialized by Lanes; this is safe.
-                if (!been_here)
-                {
+                if (!been_here) {
                         been_here= 1;
                         ... one time initializations ...
                 }
@@ -1959,8 +1958,7 @@
 <table border="1" bgcolor="#FFFFE0" cellpadding="10" style="width:50%"><tr><td><pre>
 static int clonable_lanesclone(lua_State* L)
 {
-        switch(lua_gettop(L))
-        {
+        switch(lua_gettop(L)) {
                 case 3:
                 {
                         struct s_MyClonableUserdata* self = lua_touserdata(L, 1);
@@ -1988,16 +1986,14 @@ int luaopen_deep_userdata_example(lua_State* L)
         luaL_newlib(L, deep_module);
 
         // preregister the metatables for the types we can instanciate so that Lanes can know about them
-        if (luaL_newmetatable(L, "clonable"))
-        {
+        if (luaL_newmetatable(L, "clonable")) {
                 luaL_setfuncs(L, clonable_mt, 0);
                 lua_pushvalue(L, -1);
                 lua_setfield(L, -2, "__index");
         }
         lua_setfield(L, -2, "__clonableMT"); // actual name is not important
 
-        if (luaL_newmetatable(L, "deep"))
-        {
+        if (luaL_newmetatable(L, "deep")) {
                 luaL_setfuncs(L, deep_mt, 0);
                 lua_pushvalue(L, -1);
                 lua_setfield(L, -2, "__index");
diff --git a/src/intercopycontext.cpp b/src/intercopycontext.cpp
index a8b3374..7fb2706 100644
--- a/src/intercopycontext.cpp
+++ b/src/intercopycontext.cpp
@@ -1106,10 +1106,6 @@ void InterCopyContext::interCopyString() const
 [[nodiscard]]
 InterCopyOneResult InterCopyContext::interCopyTable() const
 {
-    if (vt == VT::KEY) {
-        return InterCopyOneResult::NotCopied;
-    }
-
     STACK_CHECK_START_REL(L1, 0);
     STACK_CHECK_START_REL(L2, 0);
     DEBUGSPEW_CODE(DebugSpew(nullptr) << "TABLE " << name << std::endl);
diff --git a/unit_tests/UnitTests.vcxproj b/unit_tests/UnitTests.vcxproj
index d5edef9..300eb9b 100644
--- a/unit_tests/UnitTests.vcxproj
+++ b/unit_tests/UnitTests.vcxproj
@@ -1160,6 +1160,7 @@
     <None Include="scripts\lane\body_is_a_c_function.lua" />
     <None Include="scripts\lane\tasking_cancelling_with_hook.lua" />
     <None Include="scripts\linda\send_receive_func_and_string.lua" />
+    <None Include="scripts\linda\send_receive_tables.lua" />
     <None Include="scripts\linda\wake_period.lua" />
     <None Include="scripts\misc\deeptest.lua" />
     <None Include="scripts\_utils54.lua" />
diff --git a/unit_tests/UnitTests.vcxproj.filters b/unit_tests/UnitTests.vcxproj.filters
index 5d2dad8..57d8918 100644
--- a/unit_tests/UnitTests.vcxproj.filters
+++ b/unit_tests/UnitTests.vcxproj.filters
@@ -156,5 +156,8 @@
     <None Include="scripts\misc\deeptest.lua">
       <Filter>Scripts\misc</Filter>
     </None>
+    <None Include="scripts\linda\send_receive_tables.lua">
+      <Filter>Scripts\linda</Filter>
+    </None>
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/unit_tests/linda_tests.cpp b/unit_tests/linda_tests.cpp
index 90630a7..dfba393 100644
--- a/unit_tests/linda_tests.cpp
+++ b/unit_tests/linda_tests.cpp
@@ -398,6 +398,7 @@ TEST_CASE("scripted_tests." #DIR "." #FILE) \
 MAKE_TEST_CASE(linda, multiple_keepers)
 MAKE_TEST_CASE(linda, send_receive)
 MAKE_TEST_CASE(linda, send_receive_func_and_string)
+MAKE_TEST_CASE(linda, send_receive_tables)
 MAKE_TEST_CASE(linda, send_registered_userdata)
 MAKE_TEST_CASE(linda, wake_period)
 
diff --git a/unit_tests/scripts/linda/send_receive_tables.lua b/unit_tests/scripts/linda/send_receive_tables.lua
new file mode 100644
index 0000000..08b1f16
--- /dev/null
+++ b/unit_tests/scripts/linda/send_receive_tables.lua
@@ -0,0 +1,41 @@
+local lanes = require "lanes"
+
+-- a newly created linda doesn't contain anything
+local l = lanes.linda()
+
+-- send a table with subtables, both as keys and values, making sure the structure is preserved
+
+local t1 = {["name"] = "t1"}
+local t2 = {["name"] = "t2"}
+
+local t3 = {
+        ["name"] = "t3",
+        ["t1"] = t1,
+        [t1] = t2, -- table t1 as key, table t2 as value
+        ["t2"] = t2,
+        [t2] = t1 -- table t2 as key, table t1 as value
+}
+
+-- add recursivity for good measure
+t3["t3"] = t3
+t3[t3] = t3
+t1["t3"] = t3
+t2["t3"] = t3
+
+l:send("data", t3)
+local k, t = l:receive("data")
+assert(k == "data" and type(t) == "table" and t.name == "t3")
+-- when keys are strings
+assert(t["t3"] == t)
+assert(type(t["t1"]) == "table")
+assert(t["t1"].name == "t1")
+assert(type(t["t2"]) == "table")
+assert(t["t2"].name == "t2")
+assert(t["t1"].t3 == t)
+assert(t["t2"].t3 == t)
+-- when keys are tables
+assert(t[t.t1] == t.t2)
+assert(t[t.t1]["t3"] == t)
+assert(t[t.t2] == t.t1)
+assert(t[t.t2]["t3"] == t)
+assert(t[t.t3] == t.t3)