add file.read_combined_list(...)

src/engine.cpp

@@ -303,21 +303,28 @@ void Engine::loadContent() {
     names = manager.assembly(names);
     contentPacks = manager.getAll(names);
 
-    std::vector<PathsRoot> resRoots;
-    {
-        auto pack = ContentPack::createCore(paths);
-        resRoots.push_back({"core", pack.folder});
-        ContentLoader(&pack, contentBuilder).load();
-        load_configs(pack.folder);
-    }
+    auto corePack = ContentPack::createCore(paths);
+
+    // Setup filesystem entry points
+    std::vector<PathsRoot> resRoots {
+        {"core", corePack.folder}
+    };
     for (auto& pack : contentPacks) {
         resRoots.push_back({pack.id, pack.folder});
+    }
+    resPaths = std::make_unique<ResPaths>(resdir, resRoots);
+
+    // Load content
+    {
+        ContentLoader(&corePack, contentBuilder).load();
+        load_configs(corePack.folder);
+    }
+    for (auto& pack : contentPacks) {
         ContentLoader(&pack, contentBuilder).load();
         load_configs(pack.folder);
     } 
 
     content = contentBuilder.build();
-    resPaths = std::make_unique<ResPaths>(resdir, resRoots);
 
     langs::setup(resdir, langs::current->getId(), contentPacks);
     loadAssets();

src/files/engine_paths.cpp

@@ -10,6 +10,9 @@
 #include <utility>
 
 #include "WorldFiles.hpp"
+#include "debug/Logger.hpp"
+
+static debug::Logger logger("engine-paths");
 
 
 /// @brief ENUM for accessing folder and file names
@@ -258,6 +261,31 @@ std::vector<std::filesystem::path> ResPaths::listdir(
     return entries;
 }
 
+dv::value ResPaths::readCombinedList(const std::string& filename) {
+    dv::value list = dv::list();
+    for (const auto& root : roots) {
+        auto path = root.path / fs::u8path(filename);
+        if (!fs::exists(path)) {
+            continue;
+        }
+        try {
+            auto value = files::read_object(path);
+            if (!value.isList()) {
+                logger.warning() << "reading combined list " << root.name << ":"
+                    << filename << " is not a list (skipped)";
+                continue;
+            }
+            for (const auto& elem : value) {
+                list.add(elem);
+            }
+        } catch (const std::runtime_error& err) {
+            logger.warning() << "reading combined list " << root.name << ":" 
+                << filename << ": " << err.what();
+        }
+    }
+    return list;
+}
+
 const std::filesystem::path& ResPaths::getMainRoot() const {
     return mainRoot;
 }

src/files/engine_paths.hpp

@@ -6,6 +6,7 @@
 #include <vector>
 #include <tuple>
 
+#include "data/dv.hpp"
 #include "content/ContentPack.hpp"
 
 
@@ -63,6 +64,11 @@ public:
     std::vector<std::filesystem::path> listdir(const std::string& folder) const;
     std::vector<std::string> listdirRaw(const std::string& folder) const;
 
+    /// @brief Read all found list versions from all packs and combine into a
+    /// single list. Invalid versions will be skipped with logging a warning
+    /// @param file *.json file path relative to entry point 
+    dv::value readCombinedList(const std::string& file);
+
     const std::filesystem::path& getMainRoot() const;
 
 private:

src/files/files.hpp

@@ -63,8 +63,13 @@ namespace files {
     /// @brief Read JSON or BJSON file
     /// @param file *.json or *.bjson file
     dv::value read_json(const fs::path& file);
+    
     dv::value read_binary_json(const fs::path& file);
+    
+    /// @brief Read TOML file
+    /// @param file *.toml file
     dv::value read_toml(const fs::path& file);
+
     std::vector<std::string> read_list(const fs::path& file);
 
     bool is_data_file(const fs::path& file);

src/logic/scripting/lua/libfile.cpp

@@ -247,6 +247,14 @@ static int l_file_gzip_decompress(lua::State* L) {
     }
 }
 
+static int l_file_read_combined_list(lua::State* L) {
+    std::string path = lua::require_string(L, 1);
+    if (path.find(':') != std::string::npos) {
+        throw std::runtime_error("entry point must not be specified");
+    }
+    return lua::pushvalue(L, engine->getResPaths()->readCombinedList(path));
+}
+
 const luaL_Reg filelib[] = {
     {"exists", lua::wrap<l_file_exists>},
     {"find", lua::wrap<l_file_find>},
@@ -265,4 +273,5 @@ const luaL_Reg filelib[] = {
     {"write", lua::wrap<l_file_write>},
     {"gzip_compress", lua::wrap<l_file_gzip_compress>},
     {"gzip_decompress", lua::wrap<l_file_gzip_decompress>},
+    {"read_combined_list", lua::wrap<l_file_read_combined_list>},
     {NULL, NULL}};