I want to convert/map some &quot;data&quot; class objects to similar &quot;data&quot; class objects. For example, classes for web form to classes for database records.

    data class PersonForm(
        val firstName: String,
        val lastName: String,
        val age: Int,
        // maybe many fields exist here like address, card number, etc.
        val tel: String
    )
    // maps to ...
    data class PersonRecord(
        val name: String, // &quot;${firstName} ${lastName}&quot;
        val age: Int, // copy of age
        // maybe many fields exist here like address, card number, etc.
        val tel: String // copy of tel
    )

I use ModelMapper for such works in Java, but it can&#39;t be used because data classes are final (ModelMapper creates CGLib proxies to read mapping definitions). We can use ModelMapper when we make these classes/fields open, but we must implement features of &quot;data&quot; class manually.
(cf. ModelMapper examples: https://github.com/jhalterman/modelmapper/blob/master/examples/src/main/java/org/modelmapper/gettingstarted/GettingStartedExample.java)

How to map such &quot;data&quot; objects in Kotlin?

**Update:**
ModelMapper automatically maps fields that have same name (like tel -&gt; tel) without mapping declarations. I want to do it with data class of Kotlin.

**Update:**
The purpose of each classes depends on what kind of application, but these are probably placed in the different layer of an application.

For example:

 * data from database (Database Entity) to data for HTML form (Model/View Model)
 * REST API result to data for database

These classes are similar, but are not the same.

I want to avoid normal function calls for these reasons:

 * It depends on the order of arguments. A function for a class with many fields that have same type (like String) will be broken easily.
 * Many declarations are nesessary though most mappings can be resolved with naming convention.

Of course, a library that has similar feature is intended, but information of the Kotlin feature is also welcome (like spreading in ECMAScript).


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Better way to map Kotlin data objects to data objects