Switch to JSpecify annotations

Now, hear me out, what if instead of having three @Nullable annotations,
we had *four*?

I've been wanting to switch away from javax.annoations for a while. The
library has been deprecated for ever and, unlike other @Nullable
annotations, the annotation is attached to the parameter/function
itself, rather than the type.

We use JSpecify rather than one of the alternatives (JetBrains,
CheckerFramework) mostly because it's what NullAway recommends. We keep
CheckerFramework around for @DefaultQualifier, and JB's for @Contract.

There are some ugly changes here — for instance, `@Nullable byte[]` is
replace by `byte @Nullable`, and `@Nullable ILuaMachine.Factory` is
`ILuaMachine.@Nullable Factory`. Ughr, I understand why, but it does not
spark joy :).

projects/common-api/src/client/java/dan200/computercraft/api/client/turtle/TurtleUpgradeModeller.java

@@ -12,8 +12,8 @@ import net.minecraft.client.resources.model.ModelResourceLocation;
 import net.minecraft.client.resources.model.UnbakedModel;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.resources.ResourceLocation;
+import org.jspecify.annotations.Nullable;
 
-import javax.annotation.Nullable;
 import java.util.Collection;
 import java.util.List;
 

projects/common-api/src/client/java/dan200/computercraft/api/client/turtle/TurtleUpgradeModellers.java

@@ -14,8 +14,7 @@ import net.minecraft.client.Minecraft;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.world.item.ItemStack;
 import org.joml.Matrix4f;
-
-import javax.annotation.Nullable;
+import org.jspecify.annotations.Nullable;
 
 final class TurtleUpgradeModellers {
     private static final Transformation leftTransform = getMatrixFor(-0.4065f);

projects/common-api/src/client/java/dan200/computercraft/impl/client/ClientPlatformHelper.java

@@ -11,8 +11,7 @@ import net.minecraft.client.resources.model.ModelManager;
 import net.minecraft.client.resources.model.ModelResourceLocation;
 import net.minecraft.resources.ResourceLocation;
 import org.jetbrains.annotations.ApiStatus;
-
-import javax.annotation.Nullable;
+import org.jspecify.annotations.Nullable;
 
 @ApiStatus.Internal
 public interface ClientPlatformHelper {

projects/common-api/src/client/java/dan200/computercraft/impl/client/ComputerCraftAPIClientService.java

@@ -10,8 +10,7 @@ import dan200.computercraft.api.turtle.ITurtleUpgrade;
 import dan200.computercraft.api.turtle.TurtleUpgradeSerialiser;
 import dan200.computercraft.impl.Services;
 import org.jetbrains.annotations.ApiStatus;
-
-import javax.annotation.Nullable;
+import org.jspecify.annotations.Nullable;
 
 /**
  * Backing interface for {@link ComputerCraftAPIClient}

projects/common-api/src/main/java/dan200/computercraft/api/ComputerCraftAPI.java

@@ -26,8 +26,7 @@ import net.minecraft.core.Direction;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.level.Level;
-
-import javax.annotation.Nullable;
+import org.jspecify.annotations.Nullable;
 
 /**
  * The static entry point to the ComputerCraft API.

projects/common-api/src/main/java/dan200/computercraft/api/detail/BasicItemDetailProvider.java

@@ -6,8 +6,8 @@ package dan200.computercraft.api.detail;
 
 import net.minecraft.world.item.Item;
 import net.minecraft.world.item.ItemStack;
+import org.jspecify.annotations.Nullable;
 
-import javax.annotation.Nullable;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Objects;

projects/common-api/src/main/java/dan200/computercraft/api/detail/BlockReference.java

@@ -8,8 +8,7 @@ import net.minecraft.core.BlockPos;
 import net.minecraft.world.level.Level;
 import net.minecraft.world.level.block.entity.BlockEntity;
 import net.minecraft.world.level.block.state.BlockState;
-
-import javax.annotation.Nullable;
+import org.jspecify.annotations.Nullable;
 
 /**
  * A reference to a block in the world, used by block detail providers.

projects/common-api/src/main/java/dan200/computercraft/api/lua/IComputerSystem.java

@@ -9,8 +9,7 @@ import dan200.computercraft.api.peripheral.IComputerAccess;
 import net.minecraft.core.BlockPos;
 import net.minecraft.server.level.ServerLevel;
 import org.jetbrains.annotations.ApiStatus;
-
-import javax.annotation.Nullable;
+import org.jspecify.annotations.Nullable;
 
 /**
  * An interface passed to {@link ILuaAPIFactory} in order to provide additional information

projects/common-api/src/main/java/dan200/computercraft/api/lua/ILuaAPIFactory.java

@@ -5,8 +5,7 @@
 package dan200.computercraft.api.lua;
 
 import dan200.computercraft.api.ComputerCraftAPI;
-
-import javax.annotation.Nullable;
+import org.jspecify.annotations.Nullable;
 
 /**
  * Construct an {@link ILuaAPI} for a computer.

projects/common-api/src/main/java/dan200/computercraft/api/media/IMedia.java

@@ -12,8 +12,7 @@ import net.minecraft.server.level.ServerLevel;
 import net.minecraft.sounds.SoundEvent;
 import net.minecraft.world.item.Item;
 import net.minecraft.world.item.ItemStack;
-
-import javax.annotation.Nullable;
+import org.jspecify.annotations.Nullable;
 
 /**
  * Represents an item that can be placed in a disk drive and used by a Computer.

projects/common-api/src/main/java/dan200/computercraft/api/media/MediaProvider.java

@@ -5,8 +5,7 @@
 package dan200.computercraft.api.media;
 
 import net.minecraft.world.item.ItemStack;
-
-import javax.annotation.Nullable;
+import org.jspecify.annotations.Nullable;
 
 /**
  * This interface is used to provide {@link IMedia} implementations for {@link ItemStack}.

projects/common-api/src/main/java/dan200/computercraft/api/media/PrintoutContents.java

@@ -6,8 +6,8 @@ package dan200.computercraft.api.media;
 
 import dan200.computercraft.impl.ComputerCraftAPIService;
 import net.minecraft.world.item.ItemStack;
+import org.jspecify.annotations.Nullable;
 
-import javax.annotation.Nullable;
 import java.util.stream.Stream;
 
 /**

projects/common-api/src/main/java/dan200/computercraft/api/pocket/IPocketAccess.java

@@ -14,8 +14,8 @@ import net.minecraft.world.entity.Entity;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.phys.Vec3;
 import org.jetbrains.annotations.ApiStatus;
+import org.jspecify.annotations.Nullable;
 
-import javax.annotation.Nullable;
 import java.util.Map;
 
 /**

projects/common-api/src/main/java/dan200/computercraft/api/pocket/IPocketUpgrade.java

@@ -7,8 +7,7 @@ package dan200.computercraft.api.pocket;
 import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.api.upgrades.UpgradeBase;
 import net.minecraft.world.level.Level;
-
-import javax.annotation.Nullable;
+import org.jspecify.annotations.Nullable;
 
 /**
  * A peripheral which can be equipped to the back side of a pocket computer.

projects/common-api/src/main/java/dan200/computercraft/api/turtle/ITurtleAccess.java

@@ -17,8 +17,7 @@ import net.minecraft.world.Container;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.level.Level;
 import org.jetbrains.annotations.ApiStatus;
-
-import javax.annotation.Nullable;
+import org.jspecify.annotations.Nullable;
 
 /**
  * The interface passed to turtle by turtles, providing methods that they can call.

projects/common-api/src/main/java/dan200/computercraft/api/turtle/ITurtleUpgrade.java

@@ -9,8 +9,8 @@ import dan200.computercraft.api.upgrades.UpgradeBase;
 import net.minecraft.core.Direction;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.world.item.Items;
+import org.jspecify.annotations.Nullable;
 
-import javax.annotation.Nullable;
 import java.util.function.BiFunction;
 
 /**

projects/common-api/src/main/java/dan200/computercraft/api/turtle/TurtleCommandResult.java

@@ -5,8 +5,7 @@
 package dan200.computercraft.api.turtle;
 
 import net.minecraft.core.Direction;
-
-import javax.annotation.Nullable;
+import org.jspecify.annotations.Nullable;
 
 /**
  * Used to indicate the result of executing a turtle command.
@@ -60,9 +59,9 @@ public final class TurtleCommandResult {
 
     private final boolean success;
     private final @Nullable String errorMessage;
-    private final @Nullable Object[] results;
+    private final @Nullable Object @Nullable [] results;
 
-    private TurtleCommandResult(boolean success, @Nullable String errorMessage, @Nullable Object[] results) {
+    private TurtleCommandResult(boolean success, @Nullable String errorMessage, @Nullable Object @Nullable [] results) {
         this.success = success;
         this.errorMessage = errorMessage;
         this.results = results;
@@ -92,8 +91,7 @@ public final class TurtleCommandResult {
      *
      * @return The command's result, or {@code null} if it was a failure.
      */
-    @Nullable
-    public Object[] getResults() {
+    public @Nullable Object @Nullable [] getResults() {
         return results;
     }
 }

projects/common-api/src/main/java/dan200/computercraft/api/turtle/TurtleUpgradeDataProvider.java

@@ -18,8 +18,8 @@ import net.minecraft.world.entity.ai.attributes.Attributes;
 import net.minecraft.world.item.Item;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.level.block.Block;
+import org.jspecify.annotations.Nullable;
 
-import javax.annotation.Nullable;
 import java.util.function.Consumer;
 
 /**

projects/common-api/src/main/java/dan200/computercraft/api/upgrades/UpgradeData.java

@@ -9,8 +9,7 @@ import dan200.computercraft.api.turtle.ITurtleUpgrade;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.world.item.ItemStack;
 import org.jetbrains.annotations.Contract;
-
-import javax.annotation.Nullable;
+import org.jspecify.annotations.Nullable;
 
 /**
  * An upgrade (i.e. a {@link ITurtleUpgrade}) and its current upgrade data.

projects/common-api/src/main/java/dan200/computercraft/api/upgrades/UpgradeDataProvider.java

@@ -19,8 +19,8 @@ import net.minecraft.data.PackOutput;
 import net.minecraft.resources.ResourceKey;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.item.Item;
+import org.jspecify.annotations.Nullable;
 
-import javax.annotation.Nullable;
 import java.util.*;
 import java.util.concurrent.CompletableFuture;
 import java.util.function.Consumer;

projects/common-api/src/main/java/dan200/computercraft/impl/ComputerCraftAPIService.java

@@ -28,8 +28,7 @@ import net.minecraft.server.MinecraftServer;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.level.Level;
 import org.jetbrains.annotations.ApiStatus;
-
-import javax.annotation.Nullable;
+import org.jspecify.annotations.Nullable;
 
 /**
  * Backing interface for {@link ComputerCraftAPI}

projects/common-api/src/main/java/dan200/computercraft/impl/PlatformHelper.java

@@ -12,8 +12,7 @@ import net.minecraft.resources.ResourceKey;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.item.ItemStack;
 import org.jetbrains.annotations.ApiStatus;
-
-import javax.annotation.Nullable;
+import org.jspecify.annotations.Nullable;
 
 /**
  * Abstraction layer for Forge and Fabric. See implementations for more details.

projects/common-api/src/main/java/dan200/computercraft/impl/ServiceException.java

@@ -5,8 +5,8 @@
 package dan200.computercraft.impl;
 
 import org.jetbrains.annotations.ApiStatus;
+import org.jspecify.annotations.Nullable;
 
-import javax.annotation.Nullable;
 import java.io.Serial;
 
 /**

projects/common-api/src/main/java/dan200/computercraft/impl/Services.java

@@ -5,8 +5,8 @@
 package dan200.computercraft.impl;
 
 import org.jetbrains.annotations.ApiStatus;
+import org.jspecify.annotations.Nullable;
 
-import javax.annotation.Nullable;
 import java.util.ServiceLoader;
 import java.util.stream.Collectors;