prefixed uuid ideas

build.sbt

@@ -102,7 +102,8 @@ lazy val ce3 = (project in file("ce3"))
       "org.typelevel"               %% "cats-effect"           % "3.5.1",
       "org.typelevel"               %% "cats-parse"            % "0.3.10",
       "com.github.cb372"            %% "cats-retry"            % "3.1.0",
-      "co.fs2"                      %% "fs2-core"              % "3.8.0",
+      "co.fs2"                      %% "fs2-core"              % "3.9.1",
+      "co.fs2"                      %% "fs2-reactive-streams"  % "3.9.1",
       "co.fs2"                      %% "fs2-io"                % "3.8.0",
       "com.github.fd4s"             %% "fs2-kafka"             % "2.6.1",
       "org.typelevel"               %% "munit-cats-effect-3"   % "1.0.7",

ce3/src/main/scala/_newage/PrefixedUuidPlayground2.scala

@@ -0,0 +1,42 @@
+package _newage
+
+import cats.implicits._
+
+import java.util.UUID
+import scala.util.Try
+import cats.Show
+
+object PrefixedUuidPlayground2 extends App {
+
+  private trait IdExtractor[A] extends (A => String)
+
+  abstract class IdBase[A](private val prefix: String, private val idFn: IdExtractor[A]) {
+    implicit val show: Show[A] = (a: A) => s"$prefix${idFn(a)}"
+
+    def unapply(raw: String): Option[UUID] =
+      Option(raw)
+        .collect { case s if s.startsWith(prefix) => s.substring(prefix.length) }
+        .flatMap(s => Try(UUID.fromString(s)).toOption)
+
+    def is(raw: String): Boolean = unapply(raw).fold(false)(_ => true)
+  }
+
+  case class CarId(id: UUID) extends AnyVal
+  object CarId extends IdBase[CarId]("CAR-", _.id.toString)
+
+  // usecase
+  val s = CarId(UUID.randomUUID()).show
+  println(s)
+
+  // matching
+  def check(raw: String): Either[String, UUID] = raw match {
+    case CarId(id) => id.asRight
+    case _ => "not a car id".asLeft
+  }
+
+  Seq(
+    s,
+    "whatever"
+  ).map(x => check(x) -> CarId.is(x))
+    .foreach(println)
+}