Data types

Scalus allows you to define custom data types using Scala case classes and enums, which are compiled to equivalent Plutus structures.


import scalus.builtin.ByteString
import scalus.prelude.{*, given}
 
case class Account(hash: ByteString, balance: BigInt)
 
enum State:
    case Empty
    case Active(account: Account)
 
import State.*
compile {
    // Tuple2 literals are supported
    val tuple = (true, BigInt(123))
    val empty = State.Empty // simple constructor
    // Use `new` to create an instance
    val account = new Account(ByteString.empty, tuple._2) // access tuple fields
    // or use a companion object apply method
    val active: State = State.Active(account)
    val hash = account.hash // access case class fields
    // A simple pattern matching is supported
    // no guards, no type ascriptions.
    // Inner matches can be done only on single constructor case classes
    // Wildcard patterns are supported
    active match
        case Empty                                 => true
        case Active(account @ Account(_, balance)) => balance == BigInt(123)
    // all cases must be covered or there must be a default case
    val isEmpty = active match
        case Empty => true
        case _     => false
}