Fabric lol

- Add support for Fabric. This is mostly pretty simple, though does
   require a lot more mixins than Forge.

   Half this diff is due to data generators: we run them separately as
   some aspects (recipes mostly) are different between the loaders.

 - Add integration with Iris (same as our Oculus support) and REI
   (mostly the same as our JEI support).

 - Generic peripherals only support inventories (or rather
   InventoryStorage) right now. Supporting more of the Fabric storage
   API is going to be tricky due to the slotted nature of the API: maybe
   something to revisit after Transfer API V3 (V4?, I've lost track).

Note, this does /not/ mean I will be publishing a Fabric version of
CC:T. My plan is to rebase CC:R on top of this, hopefully simplifying
the maintenance work on their end and making the two mods a little more
consistent.

projects/common/src/main/java/dan200/computercraft/mixin/CreativeModeTabAccessor.java

@@ -6,11 +6,19 @@
 package dan200.computercraft.mixin;
 
 import net.minecraft.world.item.CreativeModeTab;
+import org.spongepowered.asm.mixin.Final;
 import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Mutable;
 import org.spongepowered.asm.mixin.gen.Accessor;
 
 @Mixin(CreativeModeTab.class)
 public interface CreativeModeTabAccessor {
     @Accessor("langId")
     String computercraft$langId();
+
+    @Final
+    @Mutable
+    @Accessor("TABS")
+    static void computercraft$setTabs(CreativeModeTab[] tabs) {
+    }
 }

projects/common/src/main/java/dan200/computercraft/shared/config/ConfigSpec.java

@@ -18,6 +18,8 @@ import net.minecraftforge.fml.config.ModConfig;
 import org.apache.logging.log4j.core.Filter;
 import org.apache.logging.log4j.core.LoggerContext;
 import org.apache.logging.log4j.core.filter.MarkerFilter;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.util.Arrays;
 import java.util.List;
@@ -25,6 +27,8 @@ import java.util.Objects;
 import java.util.concurrent.TimeUnit;
 
 public final class ConfigSpec {
+    private static final Logger LOG = LoggerFactory.getLogger(ConfigSpec.class);
+
     private static final int MODEM_MAX_RANGE = 100000;
 
     private static final String TRANSLATION_PREFIX = "gui.computercraft.config.";
@@ -337,6 +341,8 @@ public final class ConfigSpec {
     }
 
     private static void syncServer() {
+        if (!serverSpec.isLoaded()) return;
+
         // General
         Config.computerSpaceLimit = computerSpaceLimit.get();
         Config.floppySpaceLimit = floppySpaceLimit.get();
@@ -399,6 +405,8 @@ public final class ConfigSpec {
     }
 
     private static void syncClient() {
+        if (!clientSpec.isLoaded()) return;
+
         Config.monitorRenderer = monitorRenderer.get();
         Config.monitorDistance = monitorDistance.get();
         Config.uploadNagDelay = uploadNagDelay.get();
@@ -406,7 +414,17 @@ public final class ConfigSpec {
 
     public static void sync(ModConfig config) {
         if (!config.getModId().equals(ComputerCraftAPI.MOD_ID)) return;
-        if (config.getType() == ModConfig.Type.SERVER) syncServer();
-        if (config.getType() == ModConfig.Type.CLIENT) syncClient();
+
+        try {
+            if (config.getType() == ModConfig.Type.SERVER) syncServer();
+            if (config.getType() == ModConfig.Type.CLIENT) syncClient();
+        } catch (IllegalStateException e) {
+            // TODO: Remove when https://github.com/Fuzss/forgeconfigapiport-fabric/issues/26 is fixed.
+            if (e.getMessage() != null && e.getMessage().startsWith("Cannot get config value before config is loaded.")) {
+                return;
+            }
+
+            throw e;
+        }
     }
 }