how to parse kotlin code?

Besides the tools mentioned in other answers, here is another one someone may find useful:

https://github.com/kotlinx/ast

You can try Kastree -- simple library to manipulate Kotlin source code as a set of AST objects.

https://github.com/cretz/kastree

You would need to either find a Kotlin parser, or write your own.

For this subset of parsing you may be able to cheat, as data is a keyword, so if you see data with non letters each side you know it is the keyword.

For ?, it depends which meaning you want, the elvis one can be detected by the dot else try the nullable meaning if the ? is next to a letter.

I use antlr4 to do it. And I create an open source lib: https://github.com/sarahBuisson/kotlin-parser

<dependency
   <groupId>com.github.sarahbuisson</groupId>
   <artifactId>kotlin-parser</artifactId>
</dependency>