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kotlinlang

Hi, I was wondering if there was any reason Kotlin/JVM seems not to use LambdaMetaFactory when creating lambda objects by default, instead opting to make a new class for every single lambda? Also, is there any way I can tell it to use LMF? Thanks

<https://kotlinlang.org/docs/whatsnew15.html#lambdas-via-invokedynamic>

Yes and the reasons are explained there as well

&gt; A lambda compiled into invokedynamic is not serializable

So normally, you can serialize lamdas and store in database?

Yes, `kotlin.jvm.internal.Lambda` (the base class for lambdas generated by the compiler on the JVM) implements `java.io.Serializable`, so it can be serialized using the Java serialization mechanism - provided any captured variables are also serializable.

You probably should never do that though!

serializing lambdas is questionable, but serializable method references (e.g. `String::isEmpty`) could be considered reasonable

(Java 8 doesn't support serializing either, but as the linked YouTrack issue mentions, changing Kotlin's behavior is a compatibility break, although hopefully one that doesn't affect many users)

Java 8 definitely has serializable lambdas. Brian Goetz and colleagues lost many a hair over that if their talks are to trust :slightly_smiling_face:

<https://docs.oracle.com/javase/8/docs/api/java/lang/invoke/SerializedLambda.html>