Convert Experimental, DType, MethodMetadata from Java to Kotlin

Differential Revision: D106394605

Pull Request resolved: #19775

Author: kirklandsign

extension/android/BUCK

@@ -8,17 +8,19 @@ non_fbcode_target(_kind = fb_android_library,
     warnings_as_errors = False,
     required_for_source_only_abi = True,
     srcs = [
-        "executorch_android/src/main/java/org/pytorch/executorch/DType.java",
+        "executorch_android/src/main/java/org/pytorch/executorch/DType.kt",
         "executorch_android/src/main/java/org/pytorch/executorch/EValue.java",
         "executorch_android/src/main/java/org/pytorch/executorch/ExecuTorchRuntime.java",
         "executorch_android/src/main/java/org/pytorch/executorch/ExecutorchRuntimeException.java",
-        "executorch_android/src/main/java/org/pytorch/executorch/MethodMetadata.java",
+        "executorch_android/src/main/java/org/pytorch/executorch/MethodMetadata.kt",
         "executorch_android/src/main/java/org/pytorch/executorch/Module.java",
         "executorch_android/src/main/java/org/pytorch/executorch/Tensor.java",
-        "executorch_android/src/main/java/org/pytorch/executorch/annotations/Experimental.java",
+        "executorch_android/src/main/java/org/pytorch/executorch/annotations/Experimental.kt",
     ],
     autoglob = False,
-    language = "JAVA",
+    language = "KOTLIN",
+    pure_kotlin = False,
+    extra_kotlinc_arguments = ["-Xjvm-default=all"],
     deps = [
         "//fbandroid/java/com/facebook/jni:jni",
         "//fbandroid/libraries/soloader/java/com/facebook/soloader/nativeloader:nativeloader",

…n/java/org/pytorch/executorch/DType.java …ain/java/org/pytorch/executorch/DType.ktextension/android/executorch_android/src/main/java/org/pytorch/executorch/DType.java renamed to extension/android/executorch_android/src/main/java/org/pytorch/executorch/DType.kt extension/android/executorch_android/src/main/java/org/pytorch/executorch/DType.java renamed to extension/android/executorch_android/src/main/java/org/pytorch/executorch/DType.kt

@@ -6,17 +6,17 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-package org.pytorch.executorch;
+package org.pytorch.executorch
 
-import org.pytorch.executorch.annotations.Experimental;
+import org.pytorch.executorch.annotations.Experimental
 
 /**
  * Codes representing tensor data types.
  *
- * <p>Warning: These APIs are experimental and subject to change without notice
+ * Warning: These APIs are experimental and subject to change without notice
  */
 @Experimental
-public enum DType {
+enum class DType(@JvmField val jniCode: Int) {
   // NOTE: "jniCode" must be kept in sync with scalar_type.h.
   // NOTE: Never serialize "jniCode", because it can change between releases.
 
@@ -68,18 +68,10 @@ public enum DType {
   BITS16(22),
   ;
 
-  final int jniCode;
-
-  DType(int jniCode) {
-    this.jniCode = jniCode;
-  }
-
-  public static DType fromJniCode(int jniCode) {
-    for (DType dtype : values()) {
-      if (dtype.jniCode == jniCode) {
-        return dtype;
-      }
-    }
-    throw new IllegalArgumentException("No DType found for jniCode " + jniCode);
+  companion object {
+    @JvmStatic
+    fun fromJniCode(jniCode: Int): DType =
+        entries.find { it.jniCode == jniCode }
+            ?: throw IllegalArgumentException("No DType found for jniCode $jniCode")
   }
 }

extension/android/executorch_android/src/main/java/org/pytorch/executorch/MethodMetadata.java

@@ -0,0 +1,12 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package org.pytorch.executorch
+
+/** Immutable metadata for a method in a Module. */
+class MethodMetadata internal constructor(val name: String, val backends: Array<String>)

extension/android/executorch_android/src/main/java/org/pytorch/executorch/MethodMetadata.kt

@@ -6,13 +6,14 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-package org.pytorch.executorch.annotations;
+package org.pytorch.executorch.annotations
 
 /**
  * This annotation indicates that an API is experimental and may change or be removed at any time.
  * It does not provide any guarantees for API stability or backward-compatibility.
  *
- * <p>This status is not permanent, and APIs marked with this annotation will need to be either made
+ * This status is not permanent, and APIs marked with this annotation will need to be either made
  * more robust or removed in the future.
  */
-public @interface Experimental {}
+@Retention(AnnotationRetention.BINARY)
+annotation class Experimental