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Version: 2.x

Zooming In on Nested Values

Option​

We can extract a value from a Some using ZIO#some and then we can unsome it again using ZIO#unsome:

ZIO.attempt(Option("something")) // ZIO[Any, Throwable, Option[String]]
  .some                          // ZIO[Any, Option[Throwable], String]
  .unsome                        // ZIO[Any, Throwable, Option[String]]

Either​

With Either ZIO values, we can zoom in or out on the left or right side of an Either, as well as we can do the inverse and zoom out:

import zio._

val eitherEffect: ZIO[Any, Exception, Either[String, Int]] = ???

eitherEffect // ZIO[Any, Exception, Either[String, Int]]
  .left      // ZIO[Any, Either[Exception, Int], String]
  .unleft    // ZIO[Any, Exception, Either[String, Int]]

eitherEffect // ZIO[Any, Exception, Either[String, Int]]
  .right     // ZIO[Any, Either[String, Exception], Int]
  .unright   // ZIO[Any, Exception, Either[String, Int]]