Scala data modeling

Modeling Strategies

• Case Classes: Use case class for immutable data structures. They provide structural equality, pattern matching support, and a concise syntax.
• Companion Objects: Place factory methods, default values, and related logic in a companion object.
• ADT (Algebraic Data Types): Combine sealed trait with case class/case object for type-safe modeling of heterogeneous data.
• Type Aliases: Use type for simplifying complex types.

Example

sealed trait TokenValue
case class StringVal(s: String) extends TokenValue
case class NumericVal(n: Double) extends TokenValue

case class Token(value: TokenValue, metadata: Map[String, String] = Map.empty)

object Token {
  def apply(s: String): Token = new Token(StringVal(s))
}