Impl effil.next function (#142)

src/cpp/lua-module.cpp

@@ -119,6 +119,7 @@ int luaopen_effil(lua_State* L) {
             "type",         getLuaTypename,
             "pairs",        SharedTable::globalLuaPairs,
             "ipairs",       SharedTable::globalLuaIPairs,
+            "next",         SharedTable::globalLuaNext,
             "size",         luaSize,
             "dump",         luaDump,
             "hardware_threads",        std::thread::hardware_concurrency,

src/cpp/shared-table.cpp

@@ -241,7 +241,7 @@ sol::object SharedTable::luaLength(sol::this_state state) {
     return sol::make_object(state, len);
 }
 
-SharedTable::PairsIterator SharedTable::getNext(const sol::object& key, sol::this_state lua) {
+SharedTable::PairsIterator SharedTable::getNext(const sol::object& key, sol::this_state lua) const {
     SharedLock g(ctx_->lock);
     if (key) {
         auto obj = createStoredObject(key);
@@ -349,6 +349,13 @@ SharedTable::PairsIterator SharedTable::globalLuaIPairs(sol::this_state state, c
     return tbl.luaIPairs(state);
 }
 
+SharedTable::PairsIterator SharedTable::globalLuaNext(sol::this_state state, const sol::stack_object& obj, const sol::stack_object& key) {
+    REQUIRE(isSharedTable(obj)) << "bad argument #1 to 'effil.next' (effil.table expected, got " << luaTypename(obj) << ")";
+    const auto& tbl = obj.as<SharedTable>();
+    return tbl.getNext(key, state);
+}
+
+
 #undef DEFFINE_METAMETHOD_CALL_0
 #undef DEFFINE_METAMETHOD_CALL
 #undef PROXY_METAMETHOD_IMPL

src/cpp/shared-table.h

@@ -68,9 +68,10 @@ public:
     static size_t luaSize(const sol::stack_object& tbl);
     static PairsIterator globalLuaPairs(sol::this_state state, const sol::stack_object& obj);
     static PairsIterator globalLuaIPairs(sol::this_state state, const sol::stack_object& obj);
+    static PairsIterator globalLuaNext(sol::this_state state, const sol::stack_object& obj, const sol::stack_object& key);
 
 private:
-    PairsIterator getNext(const sol::object& key, sol::this_state lua);
+    PairsIterator getNext(const sol::object& key, sol::this_state lua) const;
 
 private:
     SharedTable() = default;

tests/lua/metatable.lua

@@ -181,3 +181,16 @@ test.shared_table_with_metatable.as_shared_table = function()
     share.table_key = "table_value"
     test.equal(share.table_key, "mt_table_value")
 end
+
+test.shared_table_with_metatable.next_iterator = function()
+    local visited = {a = 1, [2] = 3, [true] = "asd", [2.2] = "qwe"}
+    local share = effil.table(visited)
+
+    local key, value = effil.next(share)
+    while key do
+        test.equal(visited[key], value)
+        visited[key] = nil
+        key, value = effil.next(share, key)
+    end
+    test.is_true(next(visited) == nil) -- table is empty
+end