chore: pass ZoneLoading error as result

src/Linker/Linker.cpp

@@ -364,14 +364,16 @@ class LinkerImpl final : public Linker
                 zoneDirectory = fs::current_path();
             auto absoluteZoneDirectory = absolute(zoneDirectory).string();
 
-            auto zone = ZoneLoading::LoadZone(zonePath);
+            auto maybeZone = ZoneLoading::LoadZone(zonePath);
-            if (!zone)
+            if (!maybeZone)
             {
-                con::error("Failed to load zone \"{}\".", zonePath);
+                con::error("Failed to load zone \"{}\": {}", zonePath, maybeZone.error());
                 return false;
             }
 
-            con::debug("Load zone \"{}\"", zone->m_name);
+            auto zone = std::move(*maybeZone);
+
+            con::debug("Loaded zone \"{}\"", zone->m_name);
 
             m_loaded_zones.emplace_back(std::move(zone));
         }

src/ModMan/Context/FastFileContext.cpp

@@ -2,11 +2,11 @@
 
 #include "ZoneLoading.h"
 
-std::optional<Zone*> FastFileContext::LoadFastFile(const std::string& path)
+result::Expected<Zone*, std::string> FastFileContext::LoadFastFile(const std::string& path)
 {
     auto zone = ZoneLoading::LoadZone(path);
     if (!zone)
-        return std::nullopt;
+        return result::Unexpected(std::move(zone.error()));
 
-    return m_loaded_zones.emplace_back(std::move(zone)).get();
+    return m_loaded_zones.emplace_back(std::move(*zone)).get();
 }

src/ModMan/Context/FastFileContext.h

@@ -1,14 +1,15 @@
 #pragma once
+
+#include "Utils/Result.h"
 #include "Zone/Zone.h"
 
 #include <memory>
-#include <optional>
 #include <vector>
 
 class FastFileContext
 {
 public:
-    std::optional<Zone*> LoadFastFile(const std::string& path);
+    result::Expected<Zone*, std::string> LoadFastFile(const std::string& path);
 
     std::vector<std::unique_ptr<Zone>> m_loaded_zones;
 };

src/ModMan/Web/Binds/FastFileBinds.cpp

@@ -10,7 +10,7 @@ namespace
         ModManContext::Get().m_db_thread.Dispatch(
             [&wv, id, path]
             {
-                const auto maybeZone = ModManContext::Get().m_fast_file.LoadFastFile(path);
+                auto maybeZone = ModManContext::Get().m_fast_file.LoadFastFile(path);
 
                 if (maybeZone)
                 {
@@ -19,8 +19,8 @@ namespace
                 }
                 else
                 {
-                    con::warn("Failed to load zone \"{}\"", path);
+                    con::warn("Failed to load zone \"{}\": {}", path, maybeZone.error());
-                    ui::PromiseReject(wv, id, false);
+                    ui::PromiseReject(wv, id, std::move(maybeZone).error());
                 }
             });
     }

src/ModManUi/src/App.vue

@@ -12,8 +12,8 @@ async function onOpenFastfileClick() {
   loadingFastFile.value = true;
 
   webviewBinds.loadFastFile(lastPath.value)
-  .catch((e) => {
+  .catch((e: string) => {
-    console.error("Failed to load fastfile", e);
+    console.error("Failed to load fastfile:", e);
   })
   .finally(() => {
     loadingFastFile.value = false;

src/Unlinker/Unlinker.cpp

@@ -227,13 +227,15 @@ private:
             auto absoluteZoneDirectory = absolute(std::filesystem::path(zonePath).remove_filename()).string();
 
             auto searchPathsForZone = paths.GetSearchPathsForZone(absoluteZoneDirectory);
-            auto zone = ZoneLoading::LoadZone(zonePath);
+            auto maybeZone = ZoneLoading::LoadZone(zonePath);
-            if (zone == nullptr)
+            if (!maybeZone)
             {
-                con::error("Failed to load zone \"{}\".", zonePath);
+                con::error("Failed to load zone \"{}\": {}", zonePath, maybeZone.error());
                 return false;
             }
 
+            auto zone = std::move(*maybeZone);
+
             con::debug("Loaded zone \"{}\"", zone->m_name);
 
             if (ShouldLoadObj())
@@ -287,16 +289,16 @@ private:
 
             auto searchPathsForZone = paths.GetSearchPathsForZone(absoluteZoneDirectory);
 
-            std::string zoneName;
+            auto maybeZone = ZoneLoading::LoadZone(zonePath);
-            auto zone = ZoneLoading::LoadZone(zonePath);
+            if (!maybeZone)
-            if (zone == nullptr)
             {
-                con::error("Failed to load zone \"{}\".", zonePath);
+                con::error("Failed to load zone \"{}\": {}", zonePath, maybeZone.error());
                 return false;
             }
 
-            zoneName = zone->m_name;
+            auto zone = std::move(*maybeZone);
-            con::debug("Loaded zone \"{}\"", zoneName);
+
+            con::debug("Loaded zone \"{}\"", zone->m_name);
 
             const auto* objLoader = IObjLoader::GetObjLoaderForGame(zone->m_game_id);
             if (ShouldLoadObj())
@@ -308,6 +310,8 @@ private:
             if (ShouldLoadObj())
                 objLoader->UnloadContainersOfZone(*zone);
 
+            // Copy zone name for using it after freeing the zone
+            std::string zoneName = zone->m_name;
             zone.reset();
             con::debug("Unloaded zone \"{}\"", zoneName);
         }

src/Utils/Utils/Result.h

@@ -6,22 +6,81 @@
 using NoResult = std::monostate;
 
 // Can be replaced by std::expected with c++23
-template<typename TResult, typename TError> class Result
+namespace result
+{
+    template<typename TError> class Unexpected
     {
     public:
-    Result(TResult result)
+        Unexpected(TError result)
+            : m_data(std::move(result))
+        {
+        }
+
+        constexpr std::add_lvalue_reference_t<TError> value() &
+        {
+            return m_data;
+        }
+
+        constexpr std::add_const_t<std::add_lvalue_reference_t<TError>> value() const&
+        {
+            return m_data;
+        }
+
+        constexpr std::add_rvalue_reference_t<TError> value() &&
+        {
+            return std::move(m_data);
+        }
+
+        constexpr std::add_const_t<std::add_rvalue_reference_t<TError>> value() const&&
+        {
+            return std::move(m_data);
+        }
+
+        constexpr std::add_lvalue_reference_t<TError> operator*() &
+        {
+            return m_data;
+        }
+
+        constexpr std::add_const_t<std::add_lvalue_reference_t<TError>> operator*() const&
+        {
+            return m_data;
+        }
+
+        constexpr std::add_rvalue_reference_t<TError> operator*() &&
+        {
+            return std::move(m_data);
+        }
+
+        constexpr std::add_const_t<std::add_rvalue_reference_t<TError>> operator*() const&&
+        {
+            return std::move(m_data);
+        }
+
+        constexpr std::add_pointer_t<TError> operator->()
+        {
+            return m_data;
+        }
+
+        constexpr std::add_const_t<std::add_pointer_t<TError>> operator->() const
+        {
+            return m_data;
+        }
+
+    private:
+        TError m_data;
+    };
+
+    template<typename TResult, typename TError> class Expected
+    {
+    public:
+        Expected(TResult result)
             : m_data(std::variant<TResult, TError>(std::in_place_index<0>, std::move(result)))
         {
         }
 
-    static Result Ok(TResult result)
+        Expected(Unexpected<TError> unexpected)
+            : m_data(std::variant<TResult, TError>(std::in_place_index<1>, std::move(*unexpected)))
         {
-        return Result(std::in_place_index<0>, std::move(result));
-    }
-
-    static Result Bad(TError error)
-    {
-        return Result(std::in_place_index<1>, std::move(error));
         }
 
         constexpr operator bool() const noexcept
@@ -36,76 +95,76 @@ public:
 
         constexpr std::add_lvalue_reference_t<TResult> value() &
         {
-        return std::get<0, TResult>(m_data);
+            return std::get<0>(m_data);
         }
 
         constexpr std::add_const_t<std::add_lvalue_reference_t<TResult>> value() const&
         {
-        return std::get<0, TResult>(m_data);
+            return std::get<0>(m_data);
         }
 
         constexpr std::add_rvalue_reference_t<TResult> value() &&
         {
-        return std::move(std::get<0, TResult>(m_data));
+            return std::move(std::get<0>(m_data));
         }
 
         constexpr std::add_const_t<std::add_rvalue_reference_t<TResult>> value() const&&
         {
-        return std::move(std::get<0, TResult>(m_data));
+            return std::move(std::get<0>(m_data));
         }
 
         constexpr std::add_lvalue_reference_t<TResult> operator*() &
         {
-        return std::get<0, TResult>(m_data);
+            return std::get<0>(m_data);
         }
 
         constexpr std::add_const_t<std::add_lvalue_reference_t<TResult>> operator*() const&
         {
-        return std::get<0, TResult>(m_data);
+            return std::get<0>(m_data);
         }
 
         constexpr std::add_rvalue_reference_t<TResult> operator*() &&
         {
-        return std::move(std::get<0, TResult>(m_data));
+            return std::move(std::get<0>(m_data));
         }
 
         constexpr std::add_const_t<std::add_rvalue_reference_t<TResult>> operator*() const&&
         {
-        return std::move(std::get<0, TResult>(m_data));
+            return std::move(std::get<0>(m_data));
         }
 
         constexpr std::add_pointer_t<TResult> operator->()
         {
-        return std::get<0, TResult>(m_data);
+            return std::get<0>(m_data);
         }
 
         constexpr std::add_const_t<std::add_pointer_t<TResult>> operator->() const
         {
-        return std::get<0, TResult>(m_data);
+            return std::get<0>(m_data);
         }
 
         constexpr std::add_lvalue_reference_t<TError> error() &
         {
-        return std::get<1, TError>(m_data);
+            return std::get<1>(m_data);
         }
 
         constexpr std::add_const_t<std::add_lvalue_reference_t<TError>> error() const&
         {
-        return std::get<1, TError>(m_data);
+            return std::get<1>(m_data);
         }
 
         constexpr std::add_rvalue_reference_t<TError> error() &&
         {
-        return std::move(std::get<1, TError>(m_data));
+            return std::move(std::get<1>(m_data));
         }
 
         constexpr std::add_const_t<std::add_rvalue_reference_t<TError>> error() const&&
         {
-        return std::move(std::get<1, TError>(m_data));
+            return std::move(std::get<1>(m_data));
         }
 
     private:
-    explicit Result(std::variant<TResult, TError> data)
+        explicit Expected(std::variant<TResult, TError> data)
             : m_data(std::move(data))
         {
         }
@@ -122,3 +181,5 @@ private:
         if (!result)                                                                                                                                           \
             return result;                                                                                                                                     \
     }
+
+} // namespace result

src/ZoneLoading/ZoneLoading.cpp

@@ -2,7 +2,6 @@
 
 #include "Loading/IZoneLoaderFactory.h"
 #include "Loading/ZoneLoader.h"
-#include "Utils/Logging/Log.h"
 #include "Utils/ObjFileStream.h"
 
 #include <filesystem>
@@ -12,24 +11,18 @@
 
 namespace fs = std::filesystem;
 
-std::unique_ptr<Zone> ZoneLoading::LoadZone(const std::string& path)
+result::Expected<std::unique_ptr<Zone>, std::string> ZoneLoading::LoadZone(const std::string& path)
 {
     auto zoneName = fs::path(path).filename().replace_extension().string();
     std::ifstream file(path, std::fstream::in | std::fstream::binary);
 
     if (!file.is_open())
-    {
+        return result::Unexpected(std::format("Could not open file '{}'.", path));
-        con::error("Could not open file '{}'.", path);
-        return nullptr;
-    }
 
     ZoneHeader header{};
     file.read(reinterpret_cast<char*>(&header), sizeof(header));
     if (file.gcount() != sizeof(header))
-    {
+        return result::Unexpected(std::format("Failed to read zone header from file '{}'.", path));
-        con::error("Failed to read zone header from file '{}'.", path);
-        return nullptr;
-    }
 
     std::unique_ptr<ZoneLoader> zoneLoader;
     for (auto game = 0u; game < static_cast<unsigned>(GameId::COUNT); game++)
@@ -42,10 +35,7 @@ std::unique_ptr<Zone> ZoneLoading::LoadZone(const std::string& path)
     }
 
     if (!zoneLoader)
-    {
+        return result::Unexpected(std::format("Could not create factory for zone '{}'.", zoneName));
-        con::error("Could not create factory for zone '{}'.", zoneName);
-        return nullptr;
-    }
 
     auto loadedZone = zoneLoader->LoadZone(file);
 

src/ZoneLoading/ZoneLoading.h

@@ -1,4 +1,6 @@
 #pragma once
+
+#include "Utils/Result.h"
 #include "Zone/Zone.h"
 
 #include <string>
@@ -6,5 +8,5 @@
 class ZoneLoading
 {
 public:
-    static std::unique_ptr<Zone> LoadZone(const std::string& path);
+    static result::Expected<std::unique_ptr<Zone>, std::string> LoadZone(const std::string& path);
 };