This requires a huge rework to add arrays/list compatibility on decoder side

Author: SrRapero720

src/main/java/org/omegaconfig/ConfigSpec.java

@@ -119,7 +119,7 @@ private void load(ConfigGroup group, IFormatReader reader) {
         }
     }
 
-    void save() throws IOException {
+    public void save() throws IOException {
         IFormatWriter writer = this.format.createWritter(this.filePath);
         this.save(this, writer);
     }
@@ -206,6 +206,10 @@ private void save(ConfigGroup group, IFormatWriter writer) {
                 }
             }
 
+            if (field instanceof ListField<?> listField) {
+                writer.write(field.name(), listField.get().toArray());
+            }
+
             writer.write(field.name(), OmegaConfig.tryEncode(field.get(), field.subType()));
         }
     }

src/main/java/org/omegaconfig/OmegaConfig.java

@@ -28,13 +28,15 @@ public class OmegaConfig {
     public static Path getPath() { return CONFIG_PATH; }
     public static void setPath(Path configPath) { CONFIG_PATH = configPath; }
 
-    public static void register(ConfigSpec spec) {
+    public static ConfigSpec register(ConfigSpec spec) {
         synchronized (SPECS) {
             SPECS.put(spec.name(), spec);
         }
+
+        return spec;
     }
 
-    public static void register(Class<?> clazz) {
+    public static ConfigSpec register(Class<?> clazz) {
         Objects.requireNonNull(clazz, "Spec class cannot be null");
 
         // RETRIEVE ANNOTATION
@@ -45,16 +47,15 @@ public static void register(Class<?> clazz) {
         register$iterateClass(clazz, clazz, builder, true);
 
         // PUT ON OUR REGISTER
-        register(builder.build());
+        return register(builder.build());
     }
 
-    public static void register(Object instance) {
+    public static ConfigSpec register(Object instance) {
         Objects.requireNonNull(instance, "Spec instance cannot be null");
 
         // RETRIEVE ANNOTATION
         if (instance instanceof Class<?> clazz) {
-            register(clazz);
-            return;
+            return register(clazz);
         }
         final Class<?> specClass = instance.getClass();
         final Spec spec = Tools.specOf(specClass);
@@ -66,7 +67,7 @@ public static void register(Object instance) {
         register$iterateClass(instance, specClass, builder, false);
 
         // PUT ON OUR REGISTER
-        register(builder.build());
+        return register(builder.build());
     }
 
     private static void register$iterateClass(Object instance, Class<?> specClass, ConfigSpec.SpecBuilder builder, boolean isStatic) {

src/main/java/org/omegaconfig/Tools.java

@@ -3,9 +3,11 @@
 import org.omegaconfig.api.annotations.Spec;
 
 import java.io.Closeable;
+import java.io.FileInputStream;
 import java.io.IOException;
 import java.lang.reflect.Field;
 import java.lang.reflect.TypeVariable;
+import java.nio.file.Path;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Iterator;
@@ -183,4 +185,10 @@ public static boolean contains(char c, char[] expected) {
         }
         return false;
     }
+
+    public static byte[] readAllBytes(Path path) throws IOException {
+        try (var in = new FileInputStream(path.toFile());) {
+            return in.readAllBytes();
+        }
+    }
 }

src/main/java/org/omegaconfig/api/formats/IFormatWriter.java

@@ -19,7 +19,16 @@ public interface IFormatWriter extends Closeable {
      * @param fieldName the name of the field
      * @param value     the boolean value to write
      */
-    void write(String fieldName, String value);
+    void write(String fieldName, String value, Class<?> type, Class<?> subType);
+
+    /**
+     * Write a field on the current position.
+     * Writing is sequential, so the order of the write calls fields is important.
+     *
+     * @param fieldName the name of the field
+     * @param values     values to write
+     */
+    void write(String fieldName, String[] values, Class<?> type, Class<?> subType);
 
     /**
      * Creates a new group on the current position of the file.