Add declaration order serialization order to Adaptable

This allows the config to use the unsorted field order (which
should be the declaration order...) for serialization.

Author: Spottedleaf

src/main/java/ca/spottedleaf/yamlconfig/adapter/TypeAdapterRegistry.java

@@ -129,8 +129,8 @@ public Object serialize(final Object input, final Type type) {
         return ((TypeAdapter)adapter).serialize(this, input, type);
     }
 
-    public <T> TypeAdapter<T, Map<Object, Object>> makeAdapter(final Class<? extends T> clazz) throws Exception {
-        final TypeAdapter<T, Map<Object, Object>> ret = new AutoTypeAdapter<>(this, clazz);
+    public <T> TypeAdapter<T, Map<Object, Object>> makeAdapter(final Class<? extends T> clazz, final Adaptable adaptable) throws Exception {
+        final TypeAdapter<T, Map<Object, Object>> ret = new AutoTypeAdapter<>(this, clazz, adaptable);
 
         this.putAdapter(clazz, ret);
 
@@ -161,10 +161,10 @@ private static final class AutoTypeAdapter<T> extends TypeAdapter<T, Map<Object,
         private final Constructor<? extends T> constructor;
         private final SerializableField[] fields;
 
-        public AutoTypeAdapter(final TypeAdapterRegistry registry, final Class<? extends T> clazz) throws Exception {
+        public AutoTypeAdapter(final TypeAdapterRegistry registry, final Class<? extends T> clazz, final Adaptable adaptable) throws Exception {
             this.registry = registry;
             this.constructor = clazz.getConstructor();
-            this.fields = findSerializableFields(registry, clazz);
+            this.fields = findSerializableFields(registry, clazz, adaptable);
         }
 
         private static TypeAdapter<?, ?> findOrMakeAdapter(final TypeAdapterRegistry registry, final Class<?> clazz) throws Exception {
@@ -175,7 +175,7 @@ public AutoTypeAdapter(final TypeAdapterRegistry registry, final Class<? extends
 
             for (final Annotation annotation : clazz.getAnnotations()) {
                 if (annotation instanceof Adaptable adaptable) {
-                    return registry.makeAdapter(clazz);
+                    return registry.makeAdapter(clazz, adaptable);
                 }
             }
 
@@ -191,7 +191,7 @@ private static void ensureGenericsInitialised(final TypeAdapterRegistry registry
 
                     for (final Annotation annotation : clazz.getAnnotations()) {
                         if (annotation instanceof Adaptable adaptable) {
-                            registry.makeAdapter(clazz);
+                            registry.makeAdapter(clazz, adaptable);
                             break;
                         }
                     }
@@ -231,7 +231,8 @@ private static record SerializableField(
                 String serializedKey
         ) {}
 
-        private static SerializableField[] findSerializableFields(final TypeAdapterRegistry registry, Class<?> clazz) throws Exception {
+        private static SerializableField[] findSerializableFields(final TypeAdapterRegistry registry, Class<?> clazz,
+                                                                  final Adaptable adaptable) throws Exception {
             final List<SerializableField> ret = new ArrayList<>();
             do {
                 for (final Field field : clazz.getDeclaredFields()) {
@@ -268,9 +269,11 @@ private static SerializableField[] findSerializableFields(final TypeAdapterRegis
                 }
             } while ((clazz = clazz.getSuperclass()) != Object.class);
 
-            ret.sort((final SerializableField c1, final SerializableField c2) -> {
-                return c1.serializedKey.compareTo(c2.serializedKey);
-            });
+            if (!adaptable.useDeclarationOrder()) {
+                ret.sort((final SerializableField c1, final SerializableField c2) -> {
+                    return c1.serializedKey.compareTo(c2.serializedKey);
+                });
+            }
 
             return ret.toArray(new SerializableField[0]);
         }

src/main/java/ca/spottedleaf/yamlconfig/annotation/Adaptable.java

@@ -12,4 +12,10 @@
 @Retention(RetentionPolicy.RUNTIME)
 @Target(ElementType.TYPE)
 public @interface Adaptable {
+
+    /**
+     * Whether to use the field declaration order instead of sorting the fields by name.
+     */
+    public boolean useDeclarationOrder() default false;
+
 }

src/main/java/ca/spottedleaf/yamlconfig/config/YamlConfig.java

@@ -1,6 +1,7 @@
 package ca.spottedleaf.yamlconfig.config;
 
 import ca.spottedleaf.yamlconfig.adapter.TypeAdapterRegistry;
+import ca.spottedleaf.yamlconfig.annotation.Adaptable;
 import org.yaml.snakeyaml.DumperOptions;
 import org.yaml.snakeyaml.LoaderOptions;
 import org.yaml.snakeyaml.Yaml;
@@ -19,6 +20,7 @@
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
+import java.lang.annotation.Annotation;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.AtomicMoveNotSupportedException;
 import java.nio.file.Files;
@@ -43,10 +45,21 @@ public YamlConfig(final Class<? extends T> clazz, final T dfl) throws Exception
     }
 
     public YamlConfig(final Class<? extends T> clazz, final T dfl, final TypeAdapterRegistry registry) throws Exception {
+        Adaptable adaptable = null;
+        for (final Annotation annotation : clazz.getAnnotations()) {
+            if (annotation instanceof Adaptable a) {
+                adaptable = a;
+                break;
+            }
+        }
+        if (adaptable == null) {
+            throw new IllegalArgumentException("Class '" + clazz.getName() + "' must have the Adaptable annotation!");
+        }
+
         this.clazz = clazz;
         this.config = dfl;
         this.typeAdapters = registry;
-        this.typeAdapters.makeAdapter(clazz);
+        this.typeAdapters.makeAdapter(clazz, adaptable);
 
         final LoaderOptions loaderOptions = new LoaderOptions();
         loaderOptions.setProcessComments(true);