The Joy of Kotlin

7 Handling errors and exceptions

In this chapter

• Holding error information with the Either type
• Handling errors with the biased Result type
• Accessing and manipulating Result data
• Lifting functions to operate on Result

In chapter 6, you learned how to deal with optional data without having to manipulate null references using the Option data type. As you saw, this data type is perfect for dealing with the absence of data when that isn’t the result of an error. But it’s not an efficient way to handle errors because, although it allows you to cleanly report the absence of data, it swallows the cause of the absence. All missing data is treated the same way, and it’s up to the caller to try to figure out what happened. Often, this is impossible. ...