patryk-scalac-io

stringPrism.modifyOption(_.toUpperCase)(JStr("some"))
// res1: Option[com.example.Json] = Some(JStr(SOME))

stringPrism.modifyOption(_.toUpperCase)(JNull)
// res2: Option[com.example.Json] = None

patryk-scalac-io

stringPrism.modify(_.toUpperCase)(JNull)
//res1: Json = JNull

patryk-scalac-io

stringPrism.modify(_.toUpperCase)
//res1: com.example.Json => com.example.Json

patryk-scalac-io

val someJson: Json = JStr("someString")

val withPrism = stringPrism.modify(_.toUpperCase)(someJson)
// res1: com.example.Json = JStr(SOMESTRING)

patryk-scalac-io

val someJson: Json = JStr("someString")
someJson match {
	case JStr(s)      => JStr(s.toUpperCase)
	case anythingElse => anythingElse
}
// res1: com.example.Json = JStr(SOMESTRING)

patryk-scalac-io

stringPrism.getOption(JNull)
// res4: Option[String] = None

patryk-scalac-io

stringPrism.getOption(JStr("someString"))
// res1: Option[String] = Some(someString)

stringPrism.reverseGet("someString")
// res2: com.example.Json = JStr(someString)

patryk-scalac-io

// Based directly on definition:
val stringPrism = Prism[Json, String]{
  case JStr(v) => Some(v)
  case _       => None
}(str => JStr(str))

// The same prism but defined using `partial` helper and succinct syntax for second argument:
val stringPrism = Prism.partial[Json, String]{case JStr(v) => v}(JStr)

patryk-scalac-io

sealed trait Json
case object JNull extends Json
case class JStr(v: String) extends Json
case class JNum(v: Double) extends Json
case class JObj(v: Map[String, Json]) extends Json

patryk-scalac-io

val toUpperCase:       String => String = _.toUpperCase
val modifyStreetName:  Person => Person = streetName.modify(toUpperCase)