Handler factory method for functions returning Either (#3230)

Add Handler factory method for functions returning Either

Co-authored-by: Nabil Abdel-Hafeez <[email protected]>

zio-http/shared/src/main/scala/zio/http/Handler.scala

@@ -853,6 +853,11 @@ object Handler extends HandlerPlatformSpecific with HandlerVersionSpecific {
 
   def fromFunctionHandler[In]: FromFunctionHandler[In] = new FromFunctionHandler[In](())
 
+  /**
+   * Creates a Handler from an pure function from A to Either[E,B]
+   */
+  def fromFunctionEither[In]: FromFunctionEither[In] = new FromFunctionEither[In](())
+
   /**
    * Creates a Handler from an pure function from A to HExit[R,E,B]
    */
@@ -1222,6 +1227,18 @@ object Handler extends HandlerPlatformSpecific with HandlerVersionSpecific {
       }
   }
 
+  final class FromFunctionEither[In](val self: Unit) extends AnyVal {
+    def apply[R, Err, Out](f: In => Either[Err, Out]): Handler[Any, Err, In, Out] =
+      new Handler[Any, Err, In, Out] {
+        override def apply(in: In): ZIO[Any, Err, Out] =
+          try {
+            Exit.fromEither(f(in))
+          } catch {
+            case error: Throwable => Exit.die(error)
+          }
+      }
+  }
+
   final class FromFunctionExit[In](val self: Unit) extends AnyVal {
     def apply[R, Err, Out](f: In => Exit[Err, Out]): Handler[Any, Err, In, Out] =
       new Handler[Any, Err, In, Out] {