Add append back to LuaRef (#206)

Author: kunitoki

.github/workflows/codeql-analysis.yml

@@ -10,6 +10,8 @@ on:
       - "**/ThirdParty/**"
       - "**/CMakeLists.txt"
       - "**/.gitmodules"
+      - "!**/*.md"
+      - "!**/*.txt"
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
@@ -37,7 +39,7 @@ jobs:
     - name: Install Ninja
       run: |
         sudo apt-get update
-        sudo apt-get -y install ninja-build
+        sudo apt-get -y install ninja-build libreadline-dev
 
     - name: Initialize CodeQL
       uses: github/codeql-action/init@v3

Manual.md

@@ -1488,6 +1488,18 @@ v [3] = v [2];                       // v[2] and v[3] reference the same table
 v [2] = luabridge::LuaNil ();        // Removes the value with key = 2. The table is still referenced by v[3].
 ```
 
+To append one or more values to a sequence table, use `append`. It is equivalent to assigning to `#t + 1`, `#t + 2`, etc., and uses `lua_rawseti` internally:
+
+```cpp
+luabridge::LuaRef t = luabridge::newTable (L);
+
+t.append (1);              // t = {1}
+t.append (2, 3);           // t = {1, 2, 3}
+t.append ("hello", true);  // t = {1, 2, 3, "hello", true}
+```
+
+`append` returns `true` if all values were successfully pushed and stored, and stops early (returning `false`) if any value fails to push onto the Lua stack.
+
 4.3 - Calling Lua
 -----------------
 
@@ -1903,9 +1915,10 @@ bool operator>= (T rhs) const;
 template <class T>
 bool rawequal (T v) const;
 
-/// Append a value to a referred table. If the table is a sequence this will add another element to it.
-template <class T>
-void append (T v) const;
+/// Append one or more values to a referred table. If the table is a sequence this will add more elements to it.
+/// Uses lua_rawseti internally. Returns true if all values were successfully appended.
+template <class... Ts>
+bool append (const Ts&... vs) const;
 
 /// Return the length of a referred array. This is identical to applying the Lua # operator.
 int length () const;

Source/LuaBridge/detail/LuaRef.h

@@ -584,6 +584,39 @@ class LuaRefBase
         return get_length(m_L, -1);
     }
 
+    //=============================================================================================
+    /**
+     * @brief Append one or more values to a referred table.
+     *
+     * If the table is a sequence this will add more elements to it.
+     *
+     * @param vs Values to append.
+     *
+     * @returns True if all values were successfully appended.
+     */
+    template <class... Ts>
+    bool append(const Ts&... vs) const
+    {
+        static_assert(sizeof...(vs) > 0);
+
+        const StackRestore stackRestore(m_L);
+
+        impl().push(m_L);
+
+        int index = get_length(m_L, -1) + 1;
+
+        auto appendOne = [&](const auto& v) -> bool
+        {
+            if (! Stack<std::decay_t<decltype(v)>>::push(m_L, v))
+                return false;
+
+            lua_rawseti(m_L, -2, index++);
+            return true;
+        };
+
+        return (appendOne(vs) && ...);
+    }
+
     //=============================================================================================
     /**
      * @brief Call Lua code.

Tests/Source/LuaRefTests.cpp

@@ -766,3 +766,57 @@ TEST_F(LuaRefTests, HookTesting)
         func.second(0, "x");
     }
 }
+
+TEST_F(LuaRefTests, AppendSingleValue)
+{
+    runLua("result = {}");
+
+    EXPECT_TRUE(result().append(1));
+    EXPECT_TRUE(result().append(2));
+    EXPECT_TRUE(result().append(3));
+
+    ASSERT_EQ(3, result().length());
+    ASSERT_EQ(1, result()[1].unsafe_cast<int>());
+    ASSERT_EQ(2, result()[2].unsafe_cast<int>());
+    ASSERT_EQ(3, result()[3].unsafe_cast<int>());
+}
+
+TEST_F(LuaRefTests, AppendMultipleValues)
+{
+    runLua("result = {}");
+
+    EXPECT_TRUE(result().append(10, 20, 30));
+
+    ASSERT_EQ(3, result().length());
+    ASSERT_EQ(10, result()[1].unsafe_cast<int>());
+    ASSERT_EQ(20, result()[2].unsafe_cast<int>());
+    ASSERT_EQ(30, result()[3].unsafe_cast<int>());
+}
+
+TEST_F(LuaRefTests, AppendMixedTypes)
+{
+    runLua("result = {}");
+
+    EXPECT_TRUE(result().append(42, std::string("hello"), true, 3.14));
+
+    ASSERT_EQ(4, result().length());
+    ASSERT_EQ(42, result()[1].unsafe_cast<int>());
+    ASSERT_EQ("hello", result()[2].unsafe_cast<std::string>());
+    ASSERT_TRUE(result()[3].unsafe_cast<bool>());
+    ASSERT_DOUBLE_EQ(3.14, result()[4].unsafe_cast<double>());
+}
+
+TEST_F(LuaRefTests, AppendToExistingSequence)
+{
+    runLua("result = {10, 20}");
+
+    ASSERT_EQ(2, result().length());
+
+    EXPECT_TRUE(result().append(30, 40));
+
+    ASSERT_EQ(4, result().length());
+    ASSERT_EQ(10, result()[1].unsafe_cast<int>());
+    ASSERT_EQ(20, result()[2].unsafe_cast<int>());
+    ASSERT_EQ(30, result()[3].unsafe_cast<int>());
+    ASSERT_EQ(40, result()[4].unsafe_cast<int>());
+}