How to Print Case Classes Like Pretty Printed Tree in Scala

Suraj P Feb 02, 2024
How to Print Case Classes Like Pretty Printed Tree in Scala

This article will teach you how to print case classes like (pretty-printed) trees in Scala.

Printing the output in a tree-like fashion is highly useful when making parsers in Scala.

We have a package called sext that we can use to pretty print the case classes. It provides many useful functions, such as treeString and valueTreeString, which can print the output in a tree-like fashion.

But to make it work, we have to add a dependency in our library dependencies first. First, we have to open SBT dependency in our project and add the following line to it:

libraryDependencies += "com.github.nikita-volkov" % "sext" % "0.2.4"

Now we can use the import statement import sext._ in our program. Let us see an example to understand it better.

Example code:

object Example extends App {
    import sext._

    case class ourClass( kind : Kind, list : List[ tree ] )
    sealed trait Kind
    case object Complex extends Kind
    case class tree( a : Int, b : String )

    val store = ourClass(Complex,List(tree(1, "abcd"), tree(2, "efgh")))
    println("output using treeString:\n")
    println("output using valueTreeString:\n")


output using treeString:

- Complex
- List:
| - tree:
| | - 1
| | - abcd
| - tree:
| | - 2
| | - efgh

output using valueTreeString:

- kind:
- list:
| - - a:
| | | 1
| | - b:
| | | abcd
| - - a:
| | | 2
| | - b:
| | | efgh
Author: Suraj P
Suraj P avatar Suraj P avatar

A technophile and a Big Data developer by passion. Loves developing advance C++ and Java applications in free time works as SME at Chegg where I help students with there doubts and assignments in the field of Computer Science.

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