CanCatch
CanCatch
CanCatch lets you catch NonFatal Throwable in the F[A]
and turned it into F[Either[Throwable, A]]. It takes a function from Throwable
to your own error type, yet it can handle only NonFatal ones as already mentioned.
trait CanCatch[F[_]] {
def catchNonFatal[A, B](fb: => F[B])(f: Throwable => A): F[Either[A, B]]
def catchNonFatalEither[A, B](fab: => F[Either[A, B]])(f: Throwable => A): F[Either[A, B]]
def catchNonFatalEitherT[A, B](fab: => EitherT[F, A, B])(f: Throwable => A): EitherT[F, A, B]
}
CanCatch.catchNonFatal
CanCatch[F].catchNonFatal[A, B] lets you catch NonFatal Throwable from F[B]
and returns F[Either[A, B]].
How to Use
- Task
- Future
- Id
import monix.eval._
import effectie.monix._
val fa = CanCatch[Task].catchNonFatal(
Task(throw new RuntimeException("Something's wrong!"))
)(identity)
// fa: Task[Either[Throwable, Nothing]] = Map(
// source = FlatMap(
// source = Eval(thunk = <function0>),
// f = <function1>,
// trace = null
// ),
// f = effectie.CanCatch$$Lambda$12225/0x0000000103564040@389ba95e,
// trace = StackTrace(
// stackTrace = List(
// monix.eval.internal.TaskTracing$.buildFrame(TaskTracing.scala:52),
// monix.eval.internal.TaskTracing$.buildCachedFrame(TaskTracing.scala:43),
// monix.eval.internal.TaskTracing$.cached(TaskTracing.scala:38),
// monix.eval.Task.map(Task.scala:2027),
// effectie.monix.CanCatch$CanCatchIo$.mapFa(CanCatch.scala:28),
// effectie.monix.CanCatch$CanCatchIo$.mapFa(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatal(CanCatch.scala:22),
// effectie.CanCatch.catchNonFatal$(CanCatch.scala:21),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatal(CanCatch.scala:26),
// repl.MdocSession$App0$.<clinit>(can-catch.md:19),
// repl.MdocSession$App.<init>(can-catch.md:5),
// repl.MdocSession$.app(can-catch.md:3),
// mdoc.internal.document.DocumentBuilder$$doc$.$anonfun$build$2(DocumentBuilder.scala:89),
// scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.scala:18),
// scala.util.DynamicVariable.withValue(DynamicVariable.scala:59),
// scala.Console$.withErr(Console.scala:193),
// mdoc.internal.document.DocumentBuilder$$doc$.$anonfun$build$1(DocumentBuilder.scala:89),
// scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.scala:18),
// scala.util.DynamicVariable.withValue(DynamicVariable.scala:59),
// scala.Console$.withOut(Console.scala:164),
// mdoc.internal.document.DocumentBuilder$$doc$.build(DocumentBuilder.scala:88),
// mdoc.internal.markdown.MarkdownBuilder$.$anonfun$buildDocument$2(MarkdownBuilder.scala:47),
// mdoc.internal.markdown.MarkdownBuilder$$anon$1.run(MarkdownBuilder.scala:104)
// )
// )
// )
import monix.execution.Scheduler.Implicits.global
fa.runSyncUnsafe()
// res1: Either[Throwable, Nothing] = Left(
// value = java.lang.RuntimeException: Something's wrong!
// )
import java.util.concurrent.{ExecutorService, Executors}
import scala.concurrent.{ExecutionContext, Future, Await}
import scala.concurrent.duration._
import effectie.monix._
implicit val executorService: ExecutorService = Executors.newWorkStealingPool(Runtime.getRuntime.availableProcessors())
// executorService: ExecutorService = java.util.concurrent.ForkJoinPool@74a671e7[Running, parallelism = 4, size = 2, active = 0, running = 0, steals = 2, tasks = 0, submissions = 0]
implicit val ec: ExecutionContext = ExecutionContext.fromExecutorService(executorService)
// ec: ExecutionContext = scala.concurrent.impl.ExecutionContextImpl$$anon$4@7ee385f0
val fa = CanCatch[Future].catchNonFatal(
Future(throw new RuntimeException("Something's wrong!"))
)(identity)
// fa: Future[Either[Throwable, Nothing]] = Future(Success(Left(java.lang.RuntimeException: Something's wrong!)))
// Just for this example, you wouldn't want to do it in your production code
Await.result(fa, Duration.Inf)
// res3: Either[Throwable, Nothing] = Left(
// value = java.lang.RuntimeException: Something's wrong!
// )
NOTE
Use of Id is not recommended as Id means having no Effect. Use it only for some special cases like testing.
import cats._
import effectie.monix._
CanCatch[Id].catchNonFatal(
throw new RuntimeException("Something's wrong!")
)(identity)
// res5: Either[Throwable, Nothing] = Left(
// value = java.lang.RuntimeException: Something's wrong!
// )
Happy Path Example
- Task
- Future
- Id
import cats._
import cats.syntax.all._
import monix.eval._
import effectie.monix._
import effectie.monix.Effectful._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
}
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
CanCatch[F].catchNonFatal(
for {
a <- pureOf(n + 100)
b <- effectOf(doSomethingBad(a))
} yield b
)(MyError.nonFatalThrowable)
val fa = doSomething[Task](1)
// fa: Task[Either[MyError, Int]] = Map(
// source = FlatMap(
// source = FlatMap(
// source = Now(value = 101),
// f = <function1>,
// trace = StackTrace(
// stackTrace = List(
// monix.eval.internal.TaskTracing$.buildFrame(TaskTracing.scala:52),
// monix.eval.internal.TaskTracing$.buildCachedFrame(TaskTracing.scala:43),
// monix.eval.internal.TaskTracing$.cached(TaskTracing.scala:38),
// monix.eval.Task.flatMap(Task.scala:1792),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:39),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:33),
// cats.FlatMap$Ops.flatMap(FlatMap.scala:229),
// cats.FlatMap$Ops.flatMap$(FlatMap.scala:229),
// cats.FlatMap$ToFlatMapOps$$anon$2.flatMap(FlatMap.scala:243),
// repl.MdocSession$App6$$anonfun$doSomething$1.apply(can-catch.md:120),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:31),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatal(CanCatch.scala:22),
// effectie.CanCatch.catchNonFatal$(CanCatch.scala:21),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatal(CanCatch.scala:26),
// repl.MdocSession$App6$.doSomething(can-catch.md:123),
// repl.MdocSession$App6$.<clinit>(can-catch.md:126),
// repl.MdocSession$App4$.<clinit>(can-catch.md:77),
// repl.MdocSession$App2$.<clinit>(can-catch.md:60),
// repl.MdocSession$App0$.<clinit>(can-catch.md:28),
// repl.MdocSession$App.<init>(can-catch.md:5),
// repl.MdocSession$.app(can-catch.md:3),
// mdoc.internal.document.DocumentBuilder$$doc$.$anonfun$build$2(DocumentBuilder.scala:89),
// scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.scala:18),
// scala.util.DynamicVariable.withValue(DynamicVariable.scala:59),
// scala.Console$.withErr(Console.scala:193),
// mdoc.internal.document.DocumentBuilder$$doc$.$anonfun$build$1(DocumentBuilder.scala:89),
// scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.scala:18),
// scala.util.DynamicVariable.withValue(DynamicVariable.scala:59),
// scala.Console$.withOut(Console.scala:164),
// mdoc.internal.document.DocumentBuilder$$doc$.build(DocumentBuilder.scala:88),
// mdoc.internal.markdown.MarkdownBuilder$.$anonfun$buildDocument$2(Markd...
import monix.execution.Scheduler.Implicits.global
val result = fa.runSyncUnsafe()
// result: Either[MyError, Int] = Right(value = 202)
result match {
case Right(b) =>
println(s"Result is $b")
case Left(MyError.NonFatalThrowable(a)) =>
println(s"Result: Failed with $a")
}
// Result is 202
import java.util.concurrent.{ExecutorService, Executors}
import scala.concurrent.{ExecutionContext, Future, Await}
import scala.concurrent.duration._
import cats._
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.concurrent.ExecutorServiceOps
object MyApp {
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
}
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
CanCatch[F].catchNonFatal(
for {
a <- pureOf(n + 100)
b <- effectOf(doSomethingBad(a))
} yield b
)(MyError.nonFatalThrowable)
def main(arg: Array[String]): Unit = {
val executorService: ExecutorService =
Executors.newWorkStealingPool(Runtime.getRuntime.availableProcessors())
implicit val ec: ExecutionContext = ExecutionContext.fromExecutorService(executorService)
try {
val fa = doSomething[Future](1)
println(fa)
val result = Await.result(fa, 1.second)
println(result)
result match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
} finally {
ExecutorServiceOps.shutdownAndAwaitTermination(executorService, 1.second)
}
}
}
MyApp.main(Array.empty)
// Future(<not completed>)
// Right(202)
// Result is 202
NOTE
Use of Id is not recommended as Id means having no Effect. Use it only for some special cases like testing.
import cats._
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
}
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
CanCatch[F].catchNonFatal(
for {
a <- pureOf(n + 100)
b <- effectOf(doSomethingBad(a))
} yield b
)(MyError.nonFatalThrowable)
val fa = doSomething[Id](1)
// fa: Id[Either[MyError, Int]] = Right(value = 202)
fa match {
case Right(b) =>
println(s"Result is $b")
case Left(MyError.NonFatalThrowable(a)) =>
println(s"Result: Failed with $a")
}
// Result is 202
Unhappy Path Example
- Task
- Future
- Id
import cats._
import cats.syntax.all._
import monix.eval._
import effectie.monix._
import effectie.monix.Effectful._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
}
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
CanCatch[F].catchNonFatal(
for {
a <- pureOf(n + 100)
b <- effectOf(doSomethingBad(a))
} yield b
)(MyError.nonFatalThrowable)
val fa = doSomething[Task](-101)
// fa: Task[Either[MyError, Int]] = Map(
// source = FlatMap(
// source = FlatMap(
// source = Now(value = -1),
// f = <function1>,
// trace = StackTrace(
// stackTrace = List(
// monix.eval.internal.TaskTracing$.buildFrame(TaskTracing.scala:52),
// monix.eval.internal.TaskTracing$.buildCachedFrame(TaskTracing.scala:43),
// monix.eval.internal.TaskTracing$.cached(TaskTracing.scala:38),
// monix.eval.Task.flatMap(Task.scala:1792),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:39),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:33),
// cats.FlatMap$Ops.flatMap(FlatMap.scala:229),
// cats.FlatMap$Ops.flatMap$(FlatMap.scala:229),
// cats.FlatMap$ToFlatMapOps$$anon$2.flatMap(FlatMap.scala:243),
// repl.MdocSession$App12$$anonfun$doSomething$7.apply(can-catch.md:323),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:31),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatal(CanCatch.scala:22),
// effectie.CanCatch.catchNonFatal$(CanCatch.scala:21),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatal(CanCatch.scala:26),
// repl.MdocSession$App12$.doSomething(can-catch.md:326),
// repl.MdocSession$App12$.<clinit>(can-catch.md:329),
// repl.MdocSession$App10$.<clinit>(can-catch.md:280),
// repl.MdocSession$App8$.<clinit>(can-catch.md:223),
// repl.MdocSession$App6$.<clinit>(can-catch.md:143),
// repl.MdocSession$App4$.<clinit>(can-catch.md:77),
// repl.MdocSession$App2$.<clinit>(can-catch.md:60),
// repl.MdocSession$App0$.<clinit>(can-catch.md:28),
// repl.MdocSession$App.<init>(can-catch.md:5),
// repl.MdocSession$.app(can-catch.md:3),
// mdoc.internal.document.DocumentBuilder$$doc$.$anonfun$build$2(DocumentBuilder.scala:89),
// scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.scala:18),
// scala.util.DynamicVariable.withValue(DynamicVariable.scala:59),
// scala.Console$.withErr(Console.scala:193),
// mdoc.internal.document.DocumentBuilder$$doc$.$anonfun$build$1(DocumentBuilder.scala:89),
// scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.scala:18),
// scala.util.DynamicVariable.withValue(DynamicVariable.scala:59),
// scala.Console$.withOut(Console.scala:164),
// ...
import monix.execution.Scheduler.Implicits.global
val result = fa.runSyncUnsafe()
// result: Either[MyError, Int] = Left(
// value = NonFatalThrowable(
// throwable = java.lang.IllegalArgumentException: n cannot be a negative number. [n: -1]
// )
// )
result match {
case Right(b) =>
println(s"Result is $b")
case Left(MyError.NonFatalThrowable(a)) =>
println(s"Result: Failed with $a")
}
// Result: Failed with java.lang.IllegalArgumentException: n cannot be a negative number. [n: -1]
import java.util.concurrent.{ExecutorService, Executors}
import scala.concurrent.{ExecutionContext, Future, Await}
import scala.concurrent.duration._
import cats._
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.concurrent.ExecutorServiceOps
object MyApp {
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
}
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
CanCatch[F].catchNonFatal(
for {
a <- pureOf(n + 100)
b <- effectOf(doSomethingBad(a))
} yield b
)(MyError.nonFatalThrowable)
def main(args: Array[String]): Unit = {
val executorService: ExecutorService =
Executors.newWorkStealingPool(Runtime.getRuntime.availableProcessors())
implicit val ec: ExecutionContext = ExecutionContext.fromExecutorService(executorService)
try {
val fa = doSomething[Future](-101)
println(fa)
val result = Await.result(fa, 1.second)
println(result)
result match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
} finally {
ExecutorServiceOps.shutdownAndAwaitTermination(executorService, 1.second)
}
}
}
MyApp.main(Array.empty)
// Future(<not completed>)
// Left(NonFatalThrowable(java.lang.IllegalArgumentException: n cannot be a negative number. [n: -1]))
// Result: Failed with NonFatalThrowable(java.lang.IllegalArgumentException: n cannot be a negative number. [n: -1])
NOTE
Use of Id is not recommended as Id means having no Effect. Use it only for some special cases like testing.
import cats._
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
}
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
CanCatch[F].catchNonFatal(
for {
a <- pureOf(n + 100)
b <- effectOf(doSomethingBad(a))
} yield b
)(MyError.nonFatalThrowable)
val fa = doSomething[Id](-101)
// fa: Id[Either[MyError, Int]] = Left(
// value = NonFatalThrowable(
// throwable = java.lang.IllegalArgumentException: n cannot be a negative number. [n: -1]
// )
// )
fa match {
case Right(b) =>
println(s"Result is $b")
case Left(MyError.NonFatalThrowable(a)) =>
println(s"Result: Failed with $a")
}
// Result: Failed with java.lang.IllegalArgumentException: n cannot be a negative number. [n: -1]
CanCatch.catchNonFatalEither
CanCatch[F].catchNonFatalEither[A, B] lets you catch NonFatal Throwable from F[Either[A, B]]
and returns F[Either[A, B]].
How to Use
- Task
- Future
- Id
import monix.eval._
import effectie.monix._
val fa = CanCatch[Task].catchNonFatalEither(
Task((throw new RuntimeException("Something's wrong!")): Either[Throwable, Int])
)(identity)
// fa: Task[Either[Throwable, Int]] = Map(
// source = Map(
// source = FlatMap(
// source = Eval(thunk = <function0>),
// f = <function1>,
// trace = null
// ),
// f = effectie.CanCatch$$Lambda$12225/0x0000000103564040@6ee83025,
// trace = StackTrace(
// stackTrace = List(
// monix.eval.internal.TaskTracing$.buildFrame(TaskTracing.scala:52),
// monix.eval.internal.TaskTracing$.buildCachedFrame(TaskTracing.scala:43),
// monix.eval.internal.TaskTracing$.cached(TaskTracing.scala:38),
// monix.eval.Task.map(Task.scala:2027),
// effectie.monix.CanCatch$CanCatchIo$.mapFa(CanCatch.scala:28),
// effectie.monix.CanCatch$CanCatchIo$.mapFa(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatal(CanCatch.scala:22),
// effectie.CanCatch.catchNonFatal$(CanCatch.scala:21),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatal(CanCatch.scala:26),
// repl.MdocSession$App0$.<clinit>(can-catch.md:19),
// repl.MdocSession$App.<init>(can-catch.md:5),
// repl.MdocSession$.app(can-catch.md:3),
// mdoc.internal.document.DocumentBuilder$$doc$.$anonfun$build$2(DocumentBuilder.scala:89),
// scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.scala:18),
// scala.util.DynamicVariable.withValue(DynamicVariable.scala:59),
// scala.Console$.withErr(Console.scala:193),
// mdoc.internal.document.DocumentBuilder$$doc$.$anonfun$build$1(DocumentBuilder.scala:89),
// scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.scala:18),
// scala.util.DynamicVariable.withValue(DynamicVariable.scala:59),
// scala.Console$.withOut(Console.scala:164),
// mdoc.internal.document.DocumentBuilder$$doc$.build(DocumentBuilder.scala:88),
// mdoc.internal.markdown.MarkdownBuilder$.$anonfun$buildDocument$2(MarkdownBuilder.scala:47),
// mdoc.internal.markdown.MarkdownBuilder$$anon$1.run(MarkdownBuilder.scala:104)
// )
// )
// ),
// f = effectie.CanCatch$$Lambda$12240/0x0000000103574040@b5cb5ff,
// trace = StackTrace(
// stackTrace = List(
// monix.eval.internal.TaskTracing$.buildFrame(TaskTracing.scala:52),
// monix.eval.internal.TaskTracing$.buildCachedFrame(TaskTracing.scala:43),
// monix.eval.internal.TaskTracing$.cached(TaskTracing.scala:38),
// monix.eval.Task.map(Task.scala:2027),
// effectie.monix.CanCatch$CanCatchIo$.mapFa(CanCatch.scala:28),
// ...
import monix.execution.Scheduler.Implicits.global
fa.runSyncUnsafe()
// res19: Either[Throwable, Int] = Left(
// value = java.lang.RuntimeException: Something's wrong!
// )
import java.util.concurrent.{ExecutorService, Executors}
import scala.concurrent.{ExecutionContext, Future, Await}
import scala.concurrent.duration._
import effectie.monix._
implicit val executorService: ExecutorService = Executors.newWorkStealingPool(Runtime.getRuntime.availableProcessors())
// executorService: ExecutorService = java.util.concurrent.ForkJoinPool@4cb2d43a[Running, parallelism = 4, size = 4, active = 0, running = 0, steals = 3, tasks = 0, submissions = 0]
implicit val ec: ExecutionContext = ExecutionContext.fromExecutorService(executorService)
// ec: ExecutionContext = scala.concurrent.impl.ExecutionContextImpl$$anon$4@2e1c0459
val fa = CanCatch[Future].catchNonFatalEither(
Future((throw new RuntimeException("Something's wrong!")): Either[Throwable, Int])
)(identity)
// fa: Future[Either[Throwable, Int]] = Future(Success(Left(java.lang.RuntimeException: Something's wrong!)))
// Just for this example, you wouldn't want to do it in your production code
Await.result(fa, Duration.Inf)
// res21: Either[Throwable, Int] = Left(
// value = java.lang.RuntimeException: Something's wrong!
// )
NOTE
Use of Id is not recommended as Id means having no Effect. Use it only for some special cases like testing.
import cats._
import effectie.monix._
CanCatch[Id].catchNonFatalEither(
(throw new RuntimeException("Something's wrong!")): Either[Throwable, Int]
)(identity)
// res23: Either[Throwable, Int] = Left(
// value = java.lang.RuntimeException: Something's wrong!
// )
Happy Path Example
- Task
- Future
- Id
import cats._
import cats.syntax.all._
import monix.eval._
import effectie.monix._
import effectie.monix.Effectful._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
CanCatch[F].catchNonFatalEither(
for {
aOrB <- pureOf(divide100By(n))
c <- effectOf(aOrB.map(b => doSomethingBad(b)))
} yield c
)(MyError.nonFatalThrowable)
val fa = doSomething[Task](1)
// fa: Task[Either[MyError, Int]] = Map(
// source = Map(
// source = FlatMap(
// source = FlatMap(
// source = Now(value = Right(value = 100)),
// f = <function1>,
// trace = StackTrace(
// stackTrace = List(
// monix.eval.internal.TaskTracing$.buildFrame(TaskTracing.scala:52),
// monix.eval.internal.TaskTracing$.buildCachedFrame(TaskTracing.scala:43),
// monix.eval.internal.TaskTracing$.cached(TaskTracing.scala:38),
// monix.eval.Task.flatMap(Task.scala:1792),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:39),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:33),
// cats.FlatMap$Ops.flatMap(FlatMap.scala:229),
// cats.FlatMap$Ops.flatMap$(FlatMap.scala:229),
// cats.FlatMap$ToFlatMapOps$$anon$2.flatMap(FlatMap.scala:243),
// repl.MdocSession$App24$$anonfun$doSomething$13.apply(can-catch.md:609),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:31),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatal(CanCatch.scala:22),
// effectie.CanCatch.catchNonFatal$(CanCatch.scala:21),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatal(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatalEither(CanCatch.scala:25),
// effectie.CanCatch.catchNonFatalEither$(CanCatch.scala:24),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalEither(CanCatch.scala:26),
// repl.MdocSession$App24$.doSomething(can-catch.md:612),
// repl.MdocSession$App24$.<clinit>(can-catch.md:615),
// repl.MdocSession$App22$.<clinit>(can-catch.md:555),
// repl.MdocSession$App20$.<clinit>(can-catch.md:538),
// repl.MdocSession$App18$.<clinit>(can-catch.md:506),
// repl.MdocSession$App16$.<clinit>(can-catch.md:483),
// repl.MdocSession$App14$.<clinit>(can-catch.md:426),
// repl.MdocSession$App12$.<clinit>(can-catch.md:346),
// repl.MdocSession$App10$.<clinit>(can-catch.md:280),
// repl.MdocSession$App8$.<clinit>(can-catch.md:223),
// repl.MdocSession$App6$.<clinit>(can-catch.md:143),
// repl.MdocSession$App4$.<clinit>(can-catch.md:77),
// repl.MdocSession$App2$.<clinit>(can-catch.md:60),
// repl.MdocSession$App0$.<clinit>(can-catch.md:28),
// repl.MdocSession$App.<init>(can-catch.md:5),
// ...
import monix.execution.Scheduler.Implicits.global
val result = fa.runSyncUnsafe()
// result: Either[MyError, Int] = Right(value = 200)
result match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
// Result is 200
import java.util.concurrent.{ExecutorService, Executors}
import scala.concurrent.{ExecutionContext, Future, Await}
import scala.concurrent.duration._
import cats._
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.concurrent.ExecutorServiceOps
object MyApp {
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
CanCatch[F].catchNonFatalEither(
for {
aOrB <- pureOf(divide100By(n))
c <- effectOf(aOrB.map(b => doSomethingBad(b)))
} yield c
)(MyError.nonFatalThrowable)
def main(args: Array[String]): Unit = {
val executorService: ExecutorService =
Executors.newWorkStealingPool(Runtime.getRuntime.availableProcessors())
implicit val ec: ExecutionContext = ExecutionContext.fromExecutorService(executorService)
try {
val fa = doSomething[Future](1)
println(fa)
val result = Await.result(fa, 1.second)
println(result)
result match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
} finally {
ExecutorServiceOps.shutdownAndAwaitTermination(executorService, 1.second)
}
}
}
MyApp.main(Array.empty)
// Future(<not completed>)
// Right(200)
// Result is 200
NOTE
Use of Id is not recommended as Id means having no Effect. Use it only for some special cases like testing.
import cats._
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
CanCatch[F].catchNonFatalEither(
for {
aOrB <- pureOf(divide100By(n))
c <- effectOf(aOrB.map(b => doSomethingBad(b)))
} yield c
)(MyError.nonFatalThrowable)
val fa = doSomething[Id](1)
// fa: Id[Either[MyError, Int]] = Right(value = 200)
fa match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
// Result is 200
Unhappy Path Example
- Task
- Future
- Id
import cats._
import cats.syntax.all._
import monix.eval._
import effectie.monix._
import effectie.monix.Effectful._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
CanCatch[F].catchNonFatalEither(
for {
aOrB <- pureOf(divide100By(n))
c <- effectOf(aOrB.map(b => doSomethingBad(b)))
} yield c
)(MyError.nonFatalThrowable)
val fa = doSomething[Task](-1)
// fa: Task[Either[MyError, Int]] = Map(
// source = Map(
// source = FlatMap(
// source = FlatMap(
// source = Now(value = Right(value = -100)),
// f = <function1>,
// trace = StackTrace(
// stackTrace = List(
// monix.eval.internal.TaskTracing$.buildFrame(TaskTracing.scala:52),
// monix.eval.internal.TaskTracing$.buildCachedFrame(TaskTracing.scala:43),
// monix.eval.internal.TaskTracing$.cached(TaskTracing.scala:38),
// monix.eval.Task.flatMap(Task.scala:1792),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:39),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:33),
// cats.FlatMap$Ops.flatMap(FlatMap.scala:229),
// cats.FlatMap$Ops.flatMap$(FlatMap.scala:229),
// cats.FlatMap$ToFlatMapOps$$anon$2.flatMap(FlatMap.scala:243),
// repl.MdocSession$App30$$anonfun$doSomething$19.apply(can-catch.md:844),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:31),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatal(CanCatch.scala:22),
// effectie.CanCatch.catchNonFatal$(CanCatch.scala:21),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatal(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatalEither(CanCatch.scala:25),
// effectie.CanCatch.catchNonFatalEither$(CanCatch.scala:24),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalEither(CanCatch.scala:26),
// repl.MdocSession$App30$.doSomething(can-catch.md:847),
// repl.MdocSession$App30$.<clinit>(can-catch.md:850),
// repl.MdocSession$App28$.<clinit>(can-catch.md:790),
// repl.MdocSession$App26$.<clinit>(can-catch.md:722),
// repl.MdocSession$App24$.<clinit>(can-catch.md:632),
// repl.MdocSession$App22$.<clinit>(can-catch.md:555),
// repl.MdocSession$App20$.<clinit>(can-catch.md:538),
// repl.MdocSession$App18$.<clinit>(can-catch.md:506),
// repl.MdocSession$App16$.<clinit>(can-catch.md:483),
// repl.MdocSession$App14$.<clinit>(can-catch.md:426),
// repl.MdocSession$App12$.<clinit>(can-catch.md:346),
// repl.MdocSession$App10$.<clinit>(can-catch.md:280),
// repl.MdocSession$App8$.<clinit>(can-catch.md:223),
// repl.MdocSession$App6$.<clinit>(can-catch.md:143),
// repl.MdocSession$App4$.<clinit>(can-catch.md:77),
// ...
import monix.execution.Scheduler.Implicits.global
val result = fa.runSyncUnsafe()
// result: Either[MyError, Int] = Left(
// value = NonFatalThrowable(
// throwable = java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100]
// )
// )
result match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
// Result: Failed with NonFatalThrowable(java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100])
import java.util.concurrent.{ExecutorService, Executors}
import scala.concurrent.{ExecutionContext, Future, Await}
import scala.concurrent.duration._
import cats._
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.concurrent.ExecutorServiceOps
object MyApp {
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
CanCatch[F].catchNonFatalEither(
for {
aOrB <- pureOf(divide100By(n))
c <- effectOf(aOrB.map(b => doSomethingBad(b)))
} yield c
)(MyError.nonFatalThrowable)
def main(args: Array[String]): Unit = {
val executorService: ExecutorService =
Executors.newWorkStealingPool(Runtime.getRuntime.availableProcessors())
implicit val ec: ExecutionContext = ExecutionContext.fromExecutorService(executorService)
try {
val fa = doSomething[Future](-1)
println(fa)
val result = Await.result(fa, 1.second)
println(result)
result match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
} finally {
ExecutorServiceOps.shutdownAndAwaitTermination(executorService, 1.second)
}
}
}
MyApp.main(Array.empty)
// Future(<not completed>)
// Left(NonFatalThrowable(java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100]))
// Result: Failed with NonFatalThrowable(java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100])
NOTE
Use of Id is not recommended as Id means having no Effect. Use it only for some special cases like testing.
import cats._
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
CanCatch[F].catchNonFatalEither(
for {
aOrB <- pureOf(divide100By(n))
c <- effectOf(aOrB.map(b => doSomethingBad(b)))
} yield c
)(MyError.nonFatalThrowable)
val fa = doSomething[Id](-1)
// fa: Id[Either[MyError, Int]] = Left(
// value = NonFatalThrowable(
// throwable = java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100]
// )
// )
fa match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
// Result: Failed with NonFatalThrowable(java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100])
CanCatch.catchNonFatalEitherT
CanCatch[F].catchNonFatalEitherT[A, B] lets you catch NonFatal Throwable from EitherT[F, A, B]
and returns EitherT[F, A, B].
How to Use
- Task
- Future
- Id
import cats.data.EitherT
import monix.eval._
import effectie.monix._
val fa = CanCatch[Task].catchNonFatalEitherT(
EitherT(Task((throw new RuntimeException("Something's wrong!")): Either[Throwable, Int]))
)(identity)
// fa: EitherT[Task, Throwable, Int] = EitherT(
// value = Map(
// source = Map(
// source = FlatMap(
// source = Eval(thunk = <function0>),
// f = <function1>,
// trace = null
// ),
// f = effectie.CanCatch$$Lambda$12225/0x0000000103564040@15a60a7,
// trace = StackTrace(
// stackTrace = List(
// monix.eval.internal.TaskTracing$.buildFrame(TaskTracing.scala:52),
// monix.eval.internal.TaskTracing$.buildCachedFrame(TaskTracing.scala:43),
// monix.eval.internal.TaskTracing$.cached(TaskTracing.scala:38),
// monix.eval.Task.map(Task.scala:2027),
// effectie.monix.CanCatch$CanCatchIo$.mapFa(CanCatch.scala:28),
// effectie.monix.CanCatch$CanCatchIo$.mapFa(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatal(CanCatch.scala:22),
// effectie.CanCatch.catchNonFatal$(CanCatch.scala:21),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatal(CanCatch.scala:26),
// repl.MdocSession$App0$.<clinit>(can-catch.md:19),
// repl.MdocSession$App.<init>(can-catch.md:5),
// repl.MdocSession$.app(can-catch.md:3),
// mdoc.internal.document.DocumentBuilder$$doc$.$anonfun$build$2(DocumentBuilder.scala:89),
// scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.scala:18),
// scala.util.DynamicVariable.withValue(DynamicVariable.scala:59),
// scala.Console$.withErr(Console.scala:193),
// mdoc.internal.document.DocumentBuilder$$doc$.$anonfun$build$1(DocumentBuilder.scala:89),
// scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.scala:18),
// scala.util.DynamicVariable.withValue(DynamicVariable.scala:59),
// scala.Console$.withOut(Console.scala:164),
// mdoc.internal.document.DocumentBuilder$$doc$.build(DocumentBuilder.scala:88),
// mdoc.internal.markdown.MarkdownBuilder$.$anonfun$buildDocument$2(MarkdownBuilder.scala:47),
// mdoc.internal.markdown.MarkdownBuilder$$anon$1.run(MarkdownBuilder.scala:104)
// )
// )
// ),
// f = effectie.CanCatch$$Lambda$12240/0x0000000103574040@6f47ce3e,
// trace = StackTrace(
// stackTrace = List(
// monix.eval.internal.TaskTracing$.buildFrame(TaskTracing.scala:52),
// ...
import monix.execution.Scheduler.Implicits.global
fa.value.runSyncUnsafe()
// res37: Either[Throwable, Int] = Left(
// value = java.lang.RuntimeException: Something's wrong!
// )
import java.util.concurrent.{ExecutorService, Executors}
import scala.concurrent.{ExecutionContext, Future, Await}
import scala.concurrent.duration._
import cats.data.EitherT
import effectie.monix._
implicit val executorService: ExecutorService = Executors.newWorkStealingPool(Runtime.getRuntime.availableProcessors())
// executorService: ExecutorService = java.util.concurrent.ForkJoinPool@350ed4e8[Running, parallelism = 4, size = 4, active = 0, running = 0, steals = 3, tasks = 0, submissions = 0]
implicit val ec: ExecutionContext = ExecutionContext.fromExecutorService(executorService)
// ec: ExecutionContext = scala.concurrent.impl.ExecutionContextImpl$$anon$4@7b7e20dc
val fa = CanCatch[Future].catchNonFatalEitherT(
EitherT(Future((throw new RuntimeException("Something's wrong!")): Either[Throwable, Int]))
)(identity)
// fa: EitherT[Future, Throwable, Int] = EitherT(
// value = Future(Success(Left(java.lang.RuntimeException: Something's wrong!)))
// )
// Just for this example, you wouldn't want to do it in your production code
Await.result(fa.value, Duration.Inf)
// res39: Either[Throwable, Int] = Left(
// value = java.lang.RuntimeException: Something's wrong!
// )
NOTE
Use of Id is not recommended as Id means having no Effect. Use it only for some special cases like testing.
import cats._
import cats.data.EitherT
import effectie.monix._
val fa = CanCatch[Id].catchNonFatalEitherT(
EitherT((throw new RuntimeException("Something's wrong!")): Id[Either[Throwable, Int]])
)(identity)
// fa: EitherT[Id, Throwable, Int] = EitherT(
// value = Left(value = java.lang.RuntimeException: Something's wrong!)
// )
fa.value
// res41: Id[Either[Throwable, Int]] = Left(
// value = java.lang.RuntimeException: Something's wrong!
// )
Happy Path Example
- Task
- Future
- Id
import cats._
import cats.syntax.all._
import cats.data.EitherT
import monix.eval._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.EitherTSupport._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
CanCatch[F].catchNonFatalEitherT(
for {
b <- EitherT(pureOf(divide100By(n)))
c <- eitherTRight[MyError](doSomethingBad(b))
} yield c
)(MyError.nonFatalThrowable).value
val fa = doSomething[Task](1)
// fa: Task[Either[MyError, Int]] = Map(
// source = Map(
// source = FlatMap(
// source = FlatMap(
// source = Now(value = Right(value = 100)),
// f = cats.data.EitherT$$Lambda$12242/0x0000000103573040@2973284c,
// trace = StackTrace(
// stackTrace = List(
// monix.eval.internal.TaskTracing$.buildFrame(TaskTracing.scala:52),
// monix.eval.internal.TaskTracing$.buildCachedFrame(TaskTracing.scala:43),
// monix.eval.internal.TaskTracing$.cached(TaskTracing.scala:38),
// monix.eval.Task.flatMap(Task.scala:1792),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:39),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:33),
// cats.data.EitherT.flatMap(EitherT.scala:403),
// repl.MdocSession$App42$$anonfun$doSomething$25.apply(can-catch.md:1169),
// repl.MdocSession$App42$$anonfun$doSomething$25.apply(can-catch.md:1169),
// effectie.CanCatch.$anonfun$catchNonFatalEitherT$1(CanCatch.scala:28),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:31),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatal(CanCatch.scala:22),
// effectie.CanCatch.catchNonFatal$(CanCatch.scala:21),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatal(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatalEither(CanCatch.scala:25),
// effectie.CanCatch.catchNonFatalEither$(CanCatch.scala:24),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalEither(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatalEitherT(CanCatch.scala:28),
// effectie.CanCatch.catchNonFatalEitherT$(CanCatch.scala:27),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalEitherT(CanCatch.scala:26),
// repl.MdocSession$App42$.doSomething(can-catch.md:1172),
// repl.MdocSession$App42$.<clinit>(can-catch.md:1175),
// repl.MdocSession$App40$.<clinit>(can-catch.md:1109),
// repl.MdocSession$App38$.<clinit>(can-catch.md:1086),
// repl.MdocSession$App36$.<clinit>(can-catch.md:1051),
// repl.MdocSession$App34$.<clinit>(can-catch.md:1025),
// repl.MdocSession$App32$.<clinit>(can-catch.md:957),
// repl.MdocSession$App30$.<clinit>(can-catch.md:867),
// repl.MdocSession$App28$.<clinit>(can-catch.md:790),
// ...
import monix.execution.Scheduler.Implicits.global
val result = fa.runSyncUnsafe()
// result: Either[MyError, Int] = Right(value = 200)
result match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
// Result is 200
import java.util.concurrent.{ExecutorService, Executors}
import scala.concurrent.{ExecutionContext, Future, Await}
import scala.concurrent.duration._
import cats._
import cats.data.EitherT
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.EitherTSupport._
import effectie.concurrent.ExecutorServiceOps
object MyApp {
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
CanCatch[F].catchNonFatalEitherT(
for {
b <- EitherT(pureOf(divide100By(n)))
c <- eitherTRight[MyError](doSomethingBad(b))
} yield c
)(MyError.nonFatalThrowable).value
def main(args: Array[String]): Unit = {
val executorService: ExecutorService =
Executors.newWorkStealingPool(Runtime.getRuntime.availableProcessors())
implicit val ec: ExecutionContext = ExecutionContext.fromExecutorService(executorService)
try {
val fa = doSomething[Future](1)
println(fa)
val result = Await.result(fa, 1.second)
println(result)
result match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
} finally {
ExecutorServiceOps.shutdownAndAwaitTermination(executorService, 1.second)
}
}
}
MyApp.main(Array.empty)
// Future(<not completed>)
// Right(200)
// Result is 200
NOTE
Use of Id is not recommended as Id means having no Effect. Use it only for some special cases like testing.
import cats._
import cats.data.EitherT
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.EitherTSupport._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
CanCatch[F].catchNonFatalEitherT(
for {
b <- EitherT(pureOf(divide100By(n)))
c <- eitherTRight[MyError](doSomethingBad(b))
} yield c
)(MyError.nonFatalThrowable).value
val fa = doSomething[Id](1)
// fa: Id[Either[MyError, Int]] = Right(value = 200)
fa match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
// Result is 200
Unhappy Path Example
- Task
- Future
- Id
import cats._
import cats.data.EitherT
import cats.syntax.all._
import monix.eval._
import effectie.monix._
import effectie.monix.EitherTSupport._
import effectie.monix.Effectful._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
CanCatch[F].catchNonFatalEitherT(
for {
b <- EitherT(pureOf(divide100By(n)))
c <- eitherTRight[MyError](doSomethingBad(b))
} yield c
)(MyError.nonFatalThrowable).value
val fa = doSomething[Task](-1)
// fa: Task[Either[MyError, Int]] = Map(
// source = Map(
// source = FlatMap(
// source = FlatMap(
// source = Now(value = Right(value = -100)),
// f = cats.data.EitherT$$Lambda$12242/0x0000000103573040@78142562,
// trace = StackTrace(
// stackTrace = List(
// monix.eval.internal.TaskTracing$.buildFrame(TaskTracing.scala:52),
// monix.eval.internal.TaskTracing$.buildCachedFrame(TaskTracing.scala:43),
// monix.eval.internal.TaskTracing$.cached(TaskTracing.scala:38),
// monix.eval.Task.flatMap(Task.scala:1792),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:39),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:33),
// cats.data.EitherT.flatMap(EitherT.scala:403),
// repl.MdocSession$App42$$anonfun$doSomething$25.apply(can-catch.md:1169),
// repl.MdocSession$App42$$anonfun$doSomething$25.apply(can-catch.md:1169),
// effectie.CanCatch.$anonfun$catchNonFatalEitherT$1(CanCatch.scala:28),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:31),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatal(CanCatch.scala:22),
// effectie.CanCatch.catchNonFatal$(CanCatch.scala:21),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatal(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatalEither(CanCatch.scala:25),
// effectie.CanCatch.catchNonFatalEither$(CanCatch.scala:24),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalEither(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatalEitherT(CanCatch.scala:28),
// effectie.CanCatch.catchNonFatalEitherT$(CanCatch.scala:27),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalEitherT(CanCatch.scala:26),
// repl.MdocSession$App42$.doSomething(can-catch.md:1172),
// repl.MdocSession$App42$.<clinit>(can-catch.md:1175),
// repl.MdocSession$App40$.<clinit>(can-catch.md:1109),
// repl.MdocSession$App38$.<clinit>(can-catch.md:1086),
// repl.MdocSession$App36$.<clinit>(can-catch.md:1051),
// repl.MdocSession$App34$.<clinit>(can-catch.md:1025),
// repl.MdocSession$App32$.<clinit>(can-catch.md:957),
// repl.MdocSession$App30$.<clinit>(can-catch.md:867),
// repl.MdocSession$App28$.<clinit>(can-catch.md:790),
// ...
import monix.execution.Scheduler.Implicits.global
val result = fa.runSyncUnsafe()
// result: Either[MyError, Int] = Left(
// value = NonFatalThrowable(
// throwable = java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100]
// )
// )
result match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
// Result: Failed with NonFatalThrowable(java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100])
import java.util.concurrent.{ExecutorService, Executors}
import scala.concurrent.{ExecutionContext, Future, Await}
import scala.concurrent.duration._
import cats._
import cats.data.EitherT
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.EitherTSupport._
import effectie.concurrent.ExecutorServiceOps
object MyApp {
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
CanCatch[F].catchNonFatalEitherT(
for {
b <- EitherT(pureOf(divide100By(n)))
c <- eitherTRight[MyError](doSomethingBad(b))
} yield c
)(MyError.nonFatalThrowable).value
def main(args: Array[String]): Unit = {
val executorService: ExecutorService =
Executors.newWorkStealingPool(Runtime.getRuntime.availableProcessors())
implicit val ec: ExecutionContext = ExecutionContext.fromExecutorService(executorService)
try {
val fa = doSomething[Future](-1)
println(fa)
val result = Await.result(fa, 1.second)
println(result)
result match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
} finally {
ExecutorServiceOps.shutdownAndAwaitTermination(executorService, 1.second)
}
}
}
MyApp.main(Array.empty)
// Future(<not completed>)
// Left(NonFatalThrowable(java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100]))
// Result: Failed with NonFatalThrowable(java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100])
NOTE
Use of Id is not recommended as Id means having no Effect. Use it only for some special cases like testing.
import cats._
import cats.data.EitherT
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.EitherTSupport._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
CanCatch[F].catchNonFatalEitherT(
for {
b <- EitherT(pureOf(divide100By(n)))
c <- eitherTRight[MyError](doSomethingBad(b))
} yield c
)(MyError.nonFatalThrowable).value
val fa = doSomething[Id](-1)
// fa: Id[Either[MyError, Int]] = Left(
// value = NonFatalThrowable(
// throwable = java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100]
// )
// )
fa match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
// Result: Failed with NonFatalThrowable(java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100])
Catching
Catching.catchNonFatal provides a convenient way to use CanCatch to catch NonFatal Throwable in the F[A]
and turned it into F[Either[Throwable, A]]. Just like CanCatch, it takes a function from Throwable
to your own error type, yet it can handle only NonFatal ones as already mentioned.
Catching.catchNonFatal
catchNonFatal lets you catch NonFatal Throwable from F[B]
and returns F[Either[A, B]].
How to Use
- Task
- Future
- Id
import monix.eval._
import effectie.monix.Catching._
val fa = catchNonFatal(
Task(throw new RuntimeException("Something's wrong!"))
)(identity)
// fa: Task[Either[Throwable, Nothing]] = Map(
// source = FlatMap(
// source = Eval(thunk = <function0>),
// f = <function1>,
// trace = null
// ),
// f = effectie.CanCatch$$Lambda$12225/0x0000000103564040@3bfe171c,
// trace = StackTrace(
// stackTrace = List(
// monix.eval.internal.TaskTracing$.buildFrame(TaskTracing.scala:52),
// monix.eval.internal.TaskTracing$.buildCachedFrame(TaskTracing.scala:43),
// monix.eval.internal.TaskTracing$.cached(TaskTracing.scala:38),
// monix.eval.Task.map(Task.scala:2027),
// effectie.monix.CanCatch$CanCatchIo$.mapFa(CanCatch.scala:28),
// effectie.monix.CanCatch$CanCatchIo$.mapFa(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatal(CanCatch.scala:22),
// effectie.CanCatch.catchNonFatal$(CanCatch.scala:21),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatal(CanCatch.scala:26),
// repl.MdocSession$App0$.<clinit>(can-catch.md:19),
// repl.MdocSession$App.<init>(can-catch.md:5),
// repl.MdocSession$.app(can-catch.md:3),
// mdoc.internal.document.DocumentBuilder$$doc$.$anonfun$build$2(DocumentBuilder.scala:89),
// scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.scala:18),
// scala.util.DynamicVariable.withValue(DynamicVariable.scala:59),
// scala.Console$.withErr(Console.scala:193),
// mdoc.internal.document.DocumentBuilder$$doc$.$anonfun$build$1(DocumentBuilder.scala:89),
// scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.scala:18),
// scala.util.DynamicVariable.withValue(DynamicVariable.scala:59),
// scala.Console$.withOut(Console.scala:164),
// mdoc.internal.document.DocumentBuilder$$doc$.build(DocumentBuilder.scala:88),
// mdoc.internal.markdown.MarkdownBuilder$.$anonfun$buildDocument$2(MarkdownBuilder.scala:47),
// mdoc.internal.markdown.MarkdownBuilder$$anon$1.run(MarkdownBuilder.scala:104)
// )
// )
// )
import monix.execution.Scheduler.Implicits.global
fa.runSyncUnsafe()
// res55: Either[Throwable, Nothing] = Left(
// value = java.lang.RuntimeException: Something's wrong!
// )
import java.util.concurrent.{ExecutorService, Executors}
import scala.concurrent.{ExecutionContext, Future, Await}
import scala.concurrent.duration._
import effectie.monix.Catching._
implicit val executorService: ExecutorService = Executors.newWorkStealingPool(Runtime.getRuntime.availableProcessors())
// executorService: ExecutorService = java.util.concurrent.ForkJoinPool@310ca87f[Running, parallelism = 4, size = 3, active = 0, running = 0, steals = 2, tasks = 0, submissions = 0]
implicit val ec: ExecutionContext = ExecutionContext.fromExecutorService(executorService)
// ec: ExecutionContext = scala.concurrent.impl.ExecutionContextImpl$$anon$4@18dc75a
val fa = catchNonFatal(
Future(throw new RuntimeException("Something's wrong!"))
)(identity)
// fa: Future[Either[Throwable, Nothing]] = Future(Success(Left(java.lang.RuntimeException: Something's wrong!)))
// Just for this example, you wouldn't want to do it in your production code
Await.result(fa, Duration.Inf)
// res57: Either[Throwable, Nothing] = Left(
// value = java.lang.RuntimeException: Something's wrong!
// )
NOTE
Use of Id is not recommended as Id means having no Effect. Use it only for some special cases like testing.
import cats._
import effectie.monix.Catching._
catchNonFatal[Id](
throw new RuntimeException("Something's wrong!")
)(identity)
// res59: Id[Either[Throwable, Nothing]] = Left(
// value = java.lang.RuntimeException: Something's wrong!
// )
Happy Path Example
- Task
- Future
- Id
import cats._
import cats.syntax.all._
import monix.eval._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.Catching._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
}
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
catchNonFatal(
for {
a <- pureOf(n + 100)
b <- effectOf(doSomethingBad(a))
} yield b
)(MyError.nonFatalThrowable)
val fa = doSomething[Task](1)
// fa: Task[Either[MyError, Int]] = Map(
// source = FlatMap(
// source = FlatMap(
// source = Now(value = 101),
// f = <function1>,
// trace = StackTrace(
// stackTrace = List(
// monix.eval.internal.TaskTracing$.buildFrame(TaskTracing.scala:52),
// monix.eval.internal.TaskTracing$.buildCachedFrame(TaskTracing.scala:43),
// monix.eval.internal.TaskTracing$.cached(TaskTracing.scala:38),
// monix.eval.Task.flatMap(Task.scala:1792),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:39),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:33),
// cats.FlatMap$Ops.flatMap(FlatMap.scala:229),
// cats.FlatMap$Ops.flatMap$(FlatMap.scala:229),
// cats.FlatMap$ToFlatMapOps$$anon$2.flatMap(FlatMap.scala:243),
// repl.MdocSession$App60$$anonfun$doSomething$37.apply(can-catch.md:1733),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:31),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatal(CanCatch.scala:22),
// effectie.CanCatch.catchNonFatal$(CanCatch.scala:21),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatal(CanCatch.scala:26),
// effectie.monix.Catching$CurriedCanCatch2$.apply$extension(Catching.scala:45),
// repl.MdocSession$App60$.doSomething(can-catch.md:1736),
// repl.MdocSession$App60$.<clinit>(can-catch.md:1739),
// repl.MdocSession$App58$.<clinit>(can-catch.md:1687),
// repl.MdocSession$App56$.<clinit>(can-catch.md:1670),
// repl.MdocSession$App54$.<clinit>(can-catch.md:1638),
// repl.MdocSession$App52$.<clinit>(can-catch.md:1615),
// repl.MdocSession$App50$.<clinit>(can-catch.md:1541),
// repl.MdocSession$App48$.<clinit>(can-catch.md:1445),
// repl.MdocSession$App46$.<clinit>(can-catch.md:1362),
// repl.MdocSession$App44$.<clinit>(can-catch.md:1288),
// repl.MdocSession$App42$.<clinit>(can-catch.md:1192),
// repl.MdocSession$App40$.<clinit>(can-catch.md:1109),
// repl.MdocSession$App38$.<clinit>(can-catch.md:1086),
// repl.MdocSession$App36$.<clinit>(can-catch.md:1051),
// repl.MdocSession$App34$.<clinit>(can-catch.md:1025),
// repl.MdocSession$App32$.<clinit>(can-catch.md:957),
// repl.MdocSession$App30$.<clinit>(can-catch.md:867),
// repl.MdocSession$App28$.<clinit>(can-catch.md:790),
// repl.MdocSession$App26$.<clinit>(can-catch.md:722),
// ...
import monix.execution.Scheduler.Implicits.global
val result = fa.runSyncUnsafe()
// result: Either[MyError, Int] = Right(value = 202)
result match {
case Right(b) =>
println(s"Result is $b")
case Left(MyError.NonFatalThrowable(a)) =>
println(s"Result: Failed with $a")
}
// Result is 202
import java.util.concurrent.{ExecutorService, Executors}
import scala.concurrent.{ExecutionContext, Future, Await}
import scala.concurrent.duration._
import cats._
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.Catching._
import effectie.concurrent.ExecutorServiceOps
object MyApp {
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
}
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
catchNonFatal(
for {
a <- pureOf(n + 100)
b <- effectOf(doSomethingBad(a))
} yield b
)(MyError.nonFatalThrowable)
def main(arg: Array[String]): Unit = {
val executorService: ExecutorService =
Executors.newWorkStealingPool(Runtime.getRuntime.availableProcessors())
implicit val ec: ExecutionContext = ExecutionContext.fromExecutorService(executorService)
try {
val fa = doSomething[Future](1)
println(fa)
val result = Await.result(fa, 1.second)
println(result)
result match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
} finally {
ExecutorServiceOps.shutdownAndAwaitTermination(executorService, 1.second)
}
}
}
MyApp.main(Array.empty)
// Future(<not completed>)
// Right(202)
// Result is 202
NOTE
Use of Id is not recommended as Id means having no Effect. Use it only for some special cases like testing.
import cats._
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.Catching._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
}
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
catchNonFatal(
for {
a <- pureOf(n + 100)
b <- effectOf(doSomethingBad(a))
} yield b
)(MyError.nonFatalThrowable)
val fa = doSomething[Id](1)
// fa: Id[Either[MyError, Int]] = Right(value = 202)
fa match {
case Right(b) =>
println(s"Result is $b")
case Left(MyError.NonFatalThrowable(a)) =>
println(s"Result: Failed with $a")
}
// Result is 202
Unhappy Path Example
- Task
- Future
- Id
import cats._
import cats.syntax.all._
import monix.eval._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.Catching._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
}
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
catchNonFatal(
for {
a <- pureOf(n + 100)
b <- effectOf(doSomethingBad(a))
} yield b
)(MyError.nonFatalThrowable)
val fa = doSomething[Task](-101)
// fa: Task[Either[MyError, Int]] = Map(
// source = FlatMap(
// source = FlatMap(
// source = Now(value = -1),
// f = <function1>,
// trace = StackTrace(
// stackTrace = List(
// monix.eval.internal.TaskTracing$.buildFrame(TaskTracing.scala:52),
// monix.eval.internal.TaskTracing$.buildCachedFrame(TaskTracing.scala:43),
// monix.eval.internal.TaskTracing$.cached(TaskTracing.scala:38),
// monix.eval.Task.flatMap(Task.scala:1792),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:39),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:33),
// cats.FlatMap$Ops.flatMap(FlatMap.scala:229),
// cats.FlatMap$Ops.flatMap$(FlatMap.scala:229),
// cats.FlatMap$ToFlatMapOps$$anon$2.flatMap(FlatMap.scala:243),
// repl.MdocSession$App66$$anonfun$doSomething$43.apply(can-catch.md:1946),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:31),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatal(CanCatch.scala:22),
// effectie.CanCatch.catchNonFatal$(CanCatch.scala:21),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatal(CanCatch.scala:26),
// effectie.monix.Catching$CurriedCanCatch2$.apply$extension(Catching.scala:45),
// repl.MdocSession$App66$.doSomething(can-catch.md:1949),
// repl.MdocSession$App66$.<clinit>(can-catch.md:1952),
// repl.MdocSession$App64$.<clinit>(can-catch.md:1900),
// repl.MdocSession$App62$.<clinit>(can-catch.md:1840),
// repl.MdocSession$App60$.<clinit>(can-catch.md:1756),
// repl.MdocSession$App58$.<clinit>(can-catch.md:1687),
// repl.MdocSession$App56$.<clinit>(can-catch.md:1670),
// repl.MdocSession$App54$.<clinit>(can-catch.md:1638),
// repl.MdocSession$App52$.<clinit>(can-catch.md:1615),
// repl.MdocSession$App50$.<clinit>(can-catch.md:1541),
// repl.MdocSession$App48$.<clinit>(can-catch.md:1445),
// repl.MdocSession$App46$.<clinit>(can-catch.md:1362),
// repl.MdocSession$App44$.<clinit>(can-catch.md:1288),
// repl.MdocSession$App42$.<clinit>(can-catch.md:1192),
// repl.MdocSession$App40$.<clinit>(can-catch.md:1109),
// repl.MdocSession$App38$.<clinit>(can-catch.md:1086),
// repl.MdocSession$App36$.<clinit>(can-catch.md:1051),
// repl.MdocSession$App34$.<clinit>(can-catch.md:1025),
// repl.MdocSession$App32$.<clinit>(can-catch.md:957),
// ...
import monix.execution.Scheduler.Implicits.global
val result = fa.runSyncUnsafe()
// result: Either[MyError, Int] = Left(
// value = NonFatalThrowable(
// throwable = java.lang.IllegalArgumentException: n cannot be a negative number. [n: -1]
// )
// )
result match {
case Right(b) =>
println(s"Result is $b")
case Left(MyError.NonFatalThrowable(a)) =>
println(s"Result: Failed with $a")
}
// Result: Failed with java.lang.IllegalArgumentException: n cannot be a negative number. [n: -1]
import java.util.concurrent.{ExecutorService, Executors}
import scala.concurrent.{ExecutionContext, Future, Await}
import scala.concurrent.duration._
import cats._
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.Catching._
import effectie.concurrent.ExecutorServiceOps
object MyApp {
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
}
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
catchNonFatal(
for {
a <- pureOf(n + 100)
b <- effectOf(doSomethingBad(a))
} yield b
)(MyError.nonFatalThrowable)
def main(args: Array[String]): Unit = {
val executorService: ExecutorService =
Executors.newWorkStealingPool(Runtime.getRuntime.availableProcessors())
implicit val ec: ExecutionContext = ExecutionContext.fromExecutorService(executorService)
try {
val fa = doSomething[Future](-101)
println(fa)
val result = Await.result(fa, 1.second)
println(result)
result match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
} finally {
ExecutorServiceOps.shutdownAndAwaitTermination(executorService, 1.second)
}
}
}
MyApp.main(Array.empty)
// Future(<not completed>)
// Left(NonFatalThrowable(java.lang.IllegalArgumentException: n cannot be a negative number. [n: -1]))
// Result: Failed with NonFatalThrowable(java.lang.IllegalArgumentException: n cannot be a negative number. [n: -1])
NOTE
Use of Id is not recommended as Id means having no Effect. Use it only for some special cases like testing.
import cats._
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.Catching._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
}
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
catchNonFatal(
for {
a <- pureOf(n + 100)
b <- effectOf(doSomethingBad(a))
} yield b
)(MyError.nonFatalThrowable)
val fa = doSomething[Id](-101)
// fa: Id[Either[MyError, Int]] = Left(
// value = NonFatalThrowable(
// throwable = java.lang.IllegalArgumentException: n cannot be a negative number. [n: -1]
// )
// )
fa match {
case Right(b) =>
println(s"Result is $b")
case Left(MyError.NonFatalThrowable(a)) =>
println(s"Result: Failed with $a")
}
// Result: Failed with java.lang.IllegalArgumentException: n cannot be a negative number. [n: -1]
Catching.catchNonFatalEither
Catching.catchNonFatalEither provides a convenient way to use CanCatch
to catch NonFatal Throwable from F[Either[A, B]] and returns F[Either[A, B]].
How to Use
- Task
- Future
- Id
import monix.eval._
import effectie.monix.Catching._
val fa = catchNonFatalEither(
Task((throw new RuntimeException("Something's wrong!")): Either[Throwable, Int])
)(identity)
// fa: Task[Either[Throwable, Int]] = Map(
// source = Map(
// source = FlatMap(
// source = Eval(thunk = <function0>),
// f = <function1>,
// trace = null
// ),
// f = effectie.CanCatch$$Lambda$12225/0x0000000103564040@586bcd3c,
// trace = StackTrace(
// stackTrace = List(
// monix.eval.internal.TaskTracing$.buildFrame(TaskTracing.scala:52),
// monix.eval.internal.TaskTracing$.buildCachedFrame(TaskTracing.scala:43),
// monix.eval.internal.TaskTracing$.cached(TaskTracing.scala:38),
// monix.eval.Task.map(Task.scala:2027),
// effectie.monix.CanCatch$CanCatchIo$.mapFa(CanCatch.scala:28),
// effectie.monix.CanCatch$CanCatchIo$.mapFa(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatal(CanCatch.scala:22),
// effectie.CanCatch.catchNonFatal$(CanCatch.scala:21),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatal(CanCatch.scala:26),
// repl.MdocSession$App0$.<clinit>(can-catch.md:19),
// repl.MdocSession$App.<init>(can-catch.md:5),
// repl.MdocSession$.app(can-catch.md:3),
// mdoc.internal.document.DocumentBuilder$$doc$.$anonfun$build$2(DocumentBuilder.scala:89),
// scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.scala:18),
// scala.util.DynamicVariable.withValue(DynamicVariable.scala:59),
// scala.Console$.withErr(Console.scala:193),
// mdoc.internal.document.DocumentBuilder$$doc$.$anonfun$build$1(DocumentBuilder.scala:89),
// scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.scala:18),
// scala.util.DynamicVariable.withValue(DynamicVariable.scala:59),
// scala.Console$.withOut(Console.scala:164),
// mdoc.internal.document.DocumentBuilder$$doc$.build(DocumentBuilder.scala:88),
// mdoc.internal.markdown.MarkdownBuilder$.$anonfun$buildDocument$2(MarkdownBuilder.scala:47),
// mdoc.internal.markdown.MarkdownBuilder$$anon$1.run(MarkdownBuilder.scala:104)
// )
// )
// ),
// f = effectie.CanCatch$$Lambda$12240/0x0000000103574040@13e667da,
// trace = StackTrace(
// stackTrace = List(
// monix.eval.internal.TaskTracing$.buildFrame(TaskTracing.scala:52),
// monix.eval.internal.TaskTracing$.buildCachedFrame(TaskTracing.scala:43),
// monix.eval.internal.TaskTracing$.cached(TaskTracing.scala:38),
// monix.eval.Task.map(Task.scala:2027),
// effectie.monix.CanCatch$CanCatchIo$.mapFa(CanCatch.scala:28),
// ...
import monix.execution.Scheduler.Implicits.global
fa.runSyncUnsafe()
// res73: Either[Throwable, Int] = Left(
// value = java.lang.RuntimeException: Something's wrong!
// )
import java.util.concurrent.{ExecutorService, Executors}
import scala.concurrent.{ExecutionContext, Future, Await}
import scala.concurrent.duration._
import effectie.monix.Catching._
implicit val executorService: ExecutorService = Executors.newWorkStealingPool(Runtime.getRuntime.availableProcessors())
// executorService: ExecutorService = java.util.concurrent.ForkJoinPool@477d7a89[Running, parallelism = 4, size = 4, active = 0, running = 0, steals = 3, tasks = 0, submissions = 0]
implicit val ec: ExecutionContext = ExecutionContext.fromExecutorService(executorService)
// ec: ExecutionContext = scala.concurrent.impl.ExecutionContextImpl$$anon$4@28a5c22b
val fa = catchNonFatalEither(
Future((throw new RuntimeException("Something's wrong!")): Either[Throwable, Int])
)(identity)
// fa: Future[Either[Throwable, Int]] = Future(Success(Left(java.lang.RuntimeException: Something's wrong!)))
// Just for this example, you wouldn't want to do it in your production code
Await.result(fa, Duration.Inf)
// res75: Either[Throwable, Int] = Left(
// value = java.lang.RuntimeException: Something's wrong!
// )
NOTE
Use of Id is not recommended as Id means having no Effect. Use it only for some special cases like testing.
import cats._
import effectie.monix.Catching._
catchNonFatalEither[Id](
(throw new RuntimeException("Something's wrong!")): Either[Throwable, Int]
)(identity)
// res77: Id[Either[Throwable, Int]] = Left(
// value = java.lang.RuntimeException: Something's wrong!
// )
Happy Path Example
- Task
- Future
- Id
import cats._
import cats.syntax.all._
import monix.eval._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.Catching._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
catchNonFatalEither(
for {
aOrB <- pureOf(divide100By(n))
c <- effectOf(aOrB.map(b => doSomethingBad(b)))
} yield c
)(MyError.nonFatalThrowable)
val fa = doSomething[Task](1)
// fa: Task[Either[MyError, Int]] = Map(
// source = Map(
// source = FlatMap(
// source = FlatMap(
// source = Now(value = Right(value = 100)),
// f = <function1>,
// trace = StackTrace(
// stackTrace = List(
// monix.eval.internal.TaskTracing$.buildFrame(TaskTracing.scala:52),
// monix.eval.internal.TaskTracing$.buildCachedFrame(TaskTracing.scala:43),
// monix.eval.internal.TaskTracing$.cached(TaskTracing.scala:38),
// monix.eval.Task.flatMap(Task.scala:1792),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:39),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:33),
// cats.FlatMap$Ops.flatMap(FlatMap.scala:229),
// cats.FlatMap$Ops.flatMap$(FlatMap.scala:229),
// cats.FlatMap$ToFlatMapOps$$anon$2.flatMap(FlatMap.scala:243),
// repl.MdocSession$App78$$anonfun$doSomething$49.apply(can-catch.md:2241),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:31),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatal(CanCatch.scala:22),
// effectie.CanCatch.catchNonFatal$(CanCatch.scala:21),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatal(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatalEither(CanCatch.scala:25),
// effectie.CanCatch.catchNonFatalEither$(CanCatch.scala:24),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalEither(CanCatch.scala:26),
// effectie.monix.Catching$CurriedCanCatchEither2$.apply$extension(Catching.scala:74),
// repl.MdocSession$App78$.doSomething(can-catch.md:2244),
// repl.MdocSession$App78$.<clinit>(can-catch.md:2247),
// repl.MdocSession$App76$.<clinit>(can-catch.md:2184),
// repl.MdocSession$App74$.<clinit>(can-catch.md:2167),
// repl.MdocSession$App72$.<clinit>(can-catch.md:2135),
// repl.MdocSession$App70$.<clinit>(can-catch.md:2112),
// repl.MdocSession$App68$.<clinit>(can-catch.md:2052),
// repl.MdocSession$App66$.<clinit>(can-catch.md:1969),
// repl.MdocSession$App64$.<clinit>(can-catch.md:1900),
// repl.MdocSession$App62$.<clinit>(can-catch.md:1840),
// repl.MdocSession$App60$.<clinit>(can-catch.md:1756),
// repl.MdocSession$App58$.<clinit>(can-catch.md:1687),
// repl.MdocSession$App56$.<clinit>(can-catch.md:1670),
// ...
import monix.execution.Scheduler.Implicits.global
val result = fa.runSyncUnsafe()
// result: Either[MyError, Int] = Right(value = 200)
result match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
// Result is 200
import java.util.concurrent.{ExecutorService, Executors}
import scala.concurrent.{ExecutionContext, Future, Await}
import scala.concurrent.duration._
import cats._
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.Catching._
import effectie.concurrent.ExecutorServiceOps
object MyApp {
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
catchNonFatalEither(
for {
aOrB <- pureOf(divide100By(n))
c <- effectOf(aOrB.map(b => doSomethingBad(b)))
} yield c
)(MyError.nonFatalThrowable)
def main(args: Array[String]): Unit = {
val executorService: ExecutorService =
Executors.newWorkStealingPool(Runtime.getRuntime.availableProcessors())
implicit val ec: ExecutionContext = ExecutionContext.fromExecutorService(executorService)
try {
val fa = doSomething[Future](1)
println(fa)
val result = Await.result(fa, 1.second)
println(result)
result match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
} finally {
ExecutorServiceOps.shutdownAndAwaitTermination(executorService, 1.second)
}
}
}
MyApp.main(Array.empty)
// Future(<not completed>)
// Right(200)
// Result is 200
NOTE
Use of Id is not recommended as Id means having no Effect. Use it only for some special cases like testing.
import cats._
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.Catching._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
catchNonFatalEither(
for {
aOrB <- pureOf(divide100By(n))
c <- effectOf(aOrB.map(b => doSomethingBad(b)))
} yield c
)(MyError.nonFatalThrowable)
val fa = doSomething[Id](1)
// fa: Id[Either[MyError, Int]] = Right(value = 200)
fa match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
// Result is 200
Unhappy Path Example
- Task
- Future
- Id
import cats._
import cats.syntax.all._
import monix.eval._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.Catching._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
catchNonFatalEither(
for {
aOrB <- pureOf(divide100By(n))
c <- effectOf(aOrB.map(b => doSomethingBad(b)))
} yield c
)(MyError.nonFatalThrowable)
val fa = doSomething[Task](-1)
// fa: Task[Either[MyError, Int]] = Map(
// source = Map(
// source = FlatMap(
// source = FlatMap(
// source = Now(value = Right(value = -100)),
// f = <function1>,
// trace = StackTrace(
// stackTrace = List(
// monix.eval.internal.TaskTracing$.buildFrame(TaskTracing.scala:52),
// monix.eval.internal.TaskTracing$.buildCachedFrame(TaskTracing.scala:43),
// monix.eval.internal.TaskTracing$.cached(TaskTracing.scala:38),
// monix.eval.Task.flatMap(Task.scala:1792),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:39),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:33),
// cats.FlatMap$Ops.flatMap(FlatMap.scala:229),
// cats.FlatMap$Ops.flatMap$(FlatMap.scala:229),
// cats.FlatMap$ToFlatMapOps$$anon$2.flatMap(FlatMap.scala:243),
// repl.MdocSession$App84$$anonfun$doSomething$55.apply(can-catch.md:2485),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:31),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatal(CanCatch.scala:22),
// effectie.CanCatch.catchNonFatal$(CanCatch.scala:21),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatal(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatalEither(CanCatch.scala:25),
// effectie.CanCatch.catchNonFatalEither$(CanCatch.scala:24),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalEither(CanCatch.scala:26),
// effectie.monix.Catching$CurriedCanCatchEither2$.apply$extension(Catching.scala:74),
// repl.MdocSession$App84$.doSomething(can-catch.md:2488),
// repl.MdocSession$App84$.<clinit>(can-catch.md:2491),
// repl.MdocSession$App82$.<clinit>(can-catch.md:2428),
// repl.MdocSession$App80$.<clinit>(can-catch.md:2357),
// repl.MdocSession$App78$.<clinit>(can-catch.md:2264),
// repl.MdocSession$App76$.<clinit>(can-catch.md:2184),
// repl.MdocSession$App74$.<clinit>(can-catch.md:2167),
// repl.MdocSession$App72$.<clinit>(can-catch.md:2135),
// repl.MdocSession$App70$.<clinit>(can-catch.md:2112),
// repl.MdocSession$App68$.<clinit>(can-catch.md:2052),
// repl.MdocSession$App66$.<clinit>(can-catch.md:1969),
// repl.MdocSession$App64$.<clinit>(can-catch.md:1900),
// repl.MdocSession$App62$.<clinit>(can-catch.md:1840),
// ...
import monix.execution.Scheduler.Implicits.global
val result = fa.runSyncUnsafe()
// result: Either[MyError, Int] = Left(
// value = NonFatalThrowable(
// throwable = java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100]
// )
// )
result match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
// Result: Failed with NonFatalThrowable(java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100])
import java.util.concurrent.{ExecutorService, Executors}
import scala.concurrent.{ExecutionContext, Future, Await}
import scala.concurrent.duration._
import cats._
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.Catching._
import effectie.concurrent.ExecutorServiceOps
object MyApp {
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
catchNonFatalEither(
for {
aOrB <- pureOf(divide100By(n))
c <- effectOf(aOrB.map(b => doSomethingBad(b)))
} yield c
)(MyError.nonFatalThrowable)
def main(args: Array[String]): Unit = {
val executorService: ExecutorService =
Executors.newWorkStealingPool(Runtime.getRuntime.availableProcessors())
implicit val ec: ExecutionContext = ExecutionContext.fromExecutorService(executorService)
try {
val fa = doSomething[Future](-1)
println(fa)
val result = Await.result(fa, 1.second)
println(result)
result match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
} finally {
ExecutorServiceOps.shutdownAndAwaitTermination(executorService, 1.second)
}
}
}
MyApp.main(Array.empty)
// Future(<not completed>)
// Left(NonFatalThrowable(java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100]))
// Result: Failed with NonFatalThrowable(java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100])
NOTE
Use of Id is not recommended as Id means having no Effect. Use it only for some special cases like testing.
import cats._
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.Catching._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
catchNonFatalEither(
for {
aOrB <- pureOf(divide100By(n))
c <- effectOf(aOrB.map(b => doSomethingBad(b)))
} yield c
)(MyError.nonFatalThrowable)
val fa = doSomething[Id](-1)
// fa: Id[Either[MyError, Int]] = Left(
// value = NonFatalThrowable(
// throwable = java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100]
// )
// )
fa match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
// Result: Failed with NonFatalThrowable(java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100])
Catching.catchNonFatalEitherT
Catching.catchNonFatalEitherT provides a convenient way to use CanCatch
to catch NonFatal Throwable from EitherT[F, A, B] and returns EitherT[F, A, B].
How to Use
- Task
- Future
- Id
import cats.data.EitherT
import monix.eval._
import effectie.monix.Catching._
val fa = catchNonFatalEitherT[Task](
EitherT(Task((throw new RuntimeException("Something's wrong!")): Either[Throwable, Int]))
)(identity)
// fa: EitherT[Task, Throwable, Int] = EitherT(
// value = Map(
// source = Map(
// source = FlatMap(
// source = Eval(thunk = <function0>),
// f = <function1>,
// trace = null
// ),
// f = effectie.CanCatch$$Lambda$12225/0x0000000103564040@2e21f82e,
// trace = StackTrace(
// stackTrace = List(
// monix.eval.internal.TaskTracing$.buildFrame(TaskTracing.scala:52),
// monix.eval.internal.TaskTracing$.buildCachedFrame(TaskTracing.scala:43),
// monix.eval.internal.TaskTracing$.cached(TaskTracing.scala:38),
// monix.eval.Task.map(Task.scala:2027),
// effectie.monix.CanCatch$CanCatchIo$.mapFa(CanCatch.scala:28),
// effectie.monix.CanCatch$CanCatchIo$.mapFa(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatal(CanCatch.scala:22),
// effectie.CanCatch.catchNonFatal$(CanCatch.scala:21),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatal(CanCatch.scala:26),
// repl.MdocSession$App0$.<clinit>(can-catch.md:19),
// repl.MdocSession$App.<init>(can-catch.md:5),
// repl.MdocSession$.app(can-catch.md:3),
// mdoc.internal.document.DocumentBuilder$$doc$.$anonfun$build$2(DocumentBuilder.scala:89),
// scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.scala:18),
// scala.util.DynamicVariable.withValue(DynamicVariable.scala:59),
// scala.Console$.withErr(Console.scala:193),
// mdoc.internal.document.DocumentBuilder$$doc$.$anonfun$build$1(DocumentBuilder.scala:89),
// scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.scala:18),
// scala.util.DynamicVariable.withValue(DynamicVariable.scala:59),
// scala.Console$.withOut(Console.scala:164),
// mdoc.internal.document.DocumentBuilder$$doc$.build(DocumentBuilder.scala:88),
// mdoc.internal.markdown.MarkdownBuilder$.$anonfun$buildDocument$2(MarkdownBuilder.scala:47),
// mdoc.internal.markdown.MarkdownBuilder$$anon$1.run(MarkdownBuilder.scala:104)
// )
// )
// ),
// f = effectie.CanCatch$$Lambda$12240/0x0000000103574040@ed99287,
// trace = StackTrace(
// stackTrace = List(
// monix.eval.internal.TaskTracing$.buildFrame(TaskTracing.scala:52),
// ...
import monix.execution.Scheduler.Implicits.global
fa.value.runSyncUnsafe()
// res91: Either[Throwable, Int] = Left(
// value = java.lang.RuntimeException: Something's wrong!
// )
import java.util.concurrent.{ExecutorService, Executors}
import scala.concurrent.{ExecutionContext, Future, Await}
import scala.concurrent.duration._
import cats.data.EitherT
import effectie.monix.Catching._
implicit val executorService: ExecutorService = Executors.newWorkStealingPool(Runtime.getRuntime.availableProcessors())
// executorService: ExecutorService = java.util.concurrent.ForkJoinPool@225c08e7[Running, parallelism = 4, size = 4, active = 0, running = 0, steals = 3, tasks = 0, submissions = 0]
implicit val ec: ExecutionContext = ExecutionContext.fromExecutorService(executorService)
// ec: ExecutionContext = scala.concurrent.impl.ExecutionContextImpl$$anon$4@246e221d
val fa = catchNonFatalEitherT[Future](
EitherT(Future((throw new RuntimeException("Something's wrong!")): Either[Throwable, Int]))
)(identity)
// fa: EitherT[Future, Throwable, Int] = EitherT(
// value = Future(Success(Left(java.lang.RuntimeException: Something's wrong!)))
// )
// Just for this example, you wouldn't want to do it in your production code
Await.result(fa.value, Duration.Inf)
// res93: Either[Throwable, Int] = Left(
// value = java.lang.RuntimeException: Something's wrong!
// )
NOTE
Use of Id is not recommended as Id means having no Effect. Use it only for some special cases like testing.
import cats._
import cats.data.EitherT
import effectie.monix.Catching._
val fa = catchNonFatalEitherT[Id](
EitherT((throw new RuntimeException("Something's wrong!")): Id[Either[Throwable, Int]])
)(identity)
// fa: EitherT[Id, Throwable, Int] = EitherT(
// value = Left(value = java.lang.RuntimeException: Something's wrong!)
// )
fa.value
// res95: Id[Either[Throwable, Int]] = Left(
// value = java.lang.RuntimeException: Something's wrong!
// )
Happy Path Example
- Task
- Future
- Id
import cats._
import cats.syntax.all._
import cats.data.EitherT
import monix.eval._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.Catching._
import effectie.monix.EitherTSupport._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
catchNonFatalEitherT(
for {
b <- EitherT(pureOf(divide100By(n)))
c <- eitherTRight[MyError](doSomethingBad(b))
} yield c
)(MyError.nonFatalThrowable).value
val fa = doSomething[Task](1)
// fa: Task[Either[MyError, Int]] = Map(
// source = Map(
// source = FlatMap(
// source = FlatMap(
// source = Now(value = Right(value = 100)),
// f = cats.data.EitherT$$Lambda$12242/0x0000000103573040@5af5e36,
// trace = StackTrace(
// stackTrace = List(
// monix.eval.internal.TaskTracing$.buildFrame(TaskTracing.scala:52),
// monix.eval.internal.TaskTracing$.buildCachedFrame(TaskTracing.scala:43),
// monix.eval.internal.TaskTracing$.cached(TaskTracing.scala:38),
// monix.eval.Task.flatMap(Task.scala:1792),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:39),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:33),
// cats.data.EitherT.flatMap(EitherT.scala:403),
// repl.MdocSession$App42$$anonfun$doSomething$25.apply(can-catch.md:1169),
// repl.MdocSession$App42$$anonfun$doSomething$25.apply(can-catch.md:1169),
// effectie.CanCatch.$anonfun$catchNonFatalEitherT$1(CanCatch.scala:28),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:31),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatal(CanCatch.scala:22),
// effectie.CanCatch.catchNonFatal$(CanCatch.scala:21),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatal(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatalEither(CanCatch.scala:25),
// effectie.CanCatch.catchNonFatalEither$(CanCatch.scala:24),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalEither(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatalEitherT(CanCatch.scala:28),
// effectie.CanCatch.catchNonFatalEitherT$(CanCatch.scala:27),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalEitherT(CanCatch.scala:26),
// repl.MdocSession$App42$.doSomething(can-catch.md:1172),
// repl.MdocSession$App42$.<clinit>(can-catch.md:1175),
// repl.MdocSession$App40$.<clinit>(can-catch.md:1109),
// repl.MdocSession$App38$.<clinit>(can-catch.md:1086),
// repl.MdocSession$App36$.<clinit>(can-catch.md:1051),
// repl.MdocSession$App34$.<clinit>(can-catch.md:1025),
// repl.MdocSession$App32$.<clinit>(can-catch.md:957),
// repl.MdocSession$App30$.<clinit>(can-catch.md:867),
// repl.MdocSession$App28$.<clinit>(can-catch.md:790),
// ...
import monix.execution.Scheduler.Implicits.global
val result = fa.runSyncUnsafe()
// result: Either[MyError, Int] = Right(value = 200)
result match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
// Result is 200
import java.util.concurrent.{ExecutorService, Executors}
import scala.concurrent.{ExecutionContext, Future, Await}
import scala.concurrent.duration._
import cats._
import cats.data.EitherT
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.Catching._
import effectie.monix.EitherTSupport._
import effectie.concurrent.ExecutorServiceOps
object MyApp {
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
catchNonFatalEitherT(
for {
b <- EitherT(pureOf(divide100By(n)))
c <- eitherTRight[MyError](doSomethingBad(b))
} yield c
)(MyError.nonFatalThrowable).value
def main(args: Array[String]): Unit = {
val executorService: ExecutorService =
Executors.newWorkStealingPool(Runtime.getRuntime.availableProcessors())
implicit val ec: ExecutionContext = ExecutionContext.fromExecutorService(executorService)
try {
val fa = doSomething[Future](1)
println(fa)
val result = Await.result(fa, 1.second)
println(result)
result match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
} finally {
ExecutorServiceOps.shutdownAndAwaitTermination(executorService, 1.second)
}
}
}
MyApp.main(Array.empty)
// Future(<not completed>)
// Right(200)
// Result is 200
NOTE
Use of Id is not recommended as Id means having no Effect. Use it only for some special cases like testing.
import cats._
import cats.data.EitherT
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.Catching._
import effectie.monix.EitherTSupport._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
catchNonFatalEitherT(
for {
b <- EitherT(pureOf(divide100By(n)))
c <- eitherTRight[MyError](doSomethingBad(b))
} yield c
)(MyError.nonFatalThrowable).value
val fa = doSomething[Id](1)
// fa: Id[Either[MyError, Int]] = Right(value = 200)
fa match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
// Result is 200
Unhappy Path Example
- Task
- Future
- Id
import cats._
import cats.data.EitherT
import cats.syntax.all._
import monix.eval._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.Catching._
import effectie.monix.EitherTSupport._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
catchNonFatalEitherT(
for {
b <- EitherT(pureOf(divide100By(n)))
c <- eitherTRight[MyError](doSomethingBad(b))
} yield c
)(MyError.nonFatalThrowable).value
val fa = doSomething[Task](-1)
// fa: Task[Either[MyError, Int]] = Map(
// source = Map(
// source = FlatMap(
// source = FlatMap(
// source = Now(value = Right(value = -100)),
// f = cats.data.EitherT$$Lambda$12242/0x0000000103573040@4720a9ae,
// trace = StackTrace(
// stackTrace = List(
// monix.eval.internal.TaskTracing$.buildFrame(TaskTracing.scala:52),
// monix.eval.internal.TaskTracing$.buildCachedFrame(TaskTracing.scala:43),
// monix.eval.internal.TaskTracing$.cached(TaskTracing.scala:38),
// monix.eval.Task.flatMap(Task.scala:1792),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:39),
// monix.eval.instances.CatsBaseForTask.flatMap(CatsBaseForTask.scala:33),
// cats.data.EitherT.flatMap(EitherT.scala:403),
// repl.MdocSession$App42$$anonfun$doSomething$25.apply(can-catch.md:1169),
// repl.MdocSession$App42$$anonfun$doSomething$25.apply(can-catch.md:1169),
// effectie.CanCatch.$anonfun$catchNonFatalEitherT$1(CanCatch.scala:28),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:31),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalThrowable(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatal(CanCatch.scala:22),
// effectie.CanCatch.catchNonFatal$(CanCatch.scala:21),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatal(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatalEither(CanCatch.scala:25),
// effectie.CanCatch.catchNonFatalEither$(CanCatch.scala:24),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalEither(CanCatch.scala:26),
// effectie.CanCatch.catchNonFatalEitherT(CanCatch.scala:28),
// effectie.CanCatch.catchNonFatalEitherT$(CanCatch.scala:27),
// effectie.monix.CanCatch$CanCatchIo$.catchNonFatalEitherT(CanCatch.scala:26),
// repl.MdocSession$App42$.doSomething(can-catch.md:1172),
// repl.MdocSession$App42$.<clinit>(can-catch.md:1175),
// repl.MdocSession$App40$.<clinit>(can-catch.md:1109),
// repl.MdocSession$App38$.<clinit>(can-catch.md:1086),
// repl.MdocSession$App36$.<clinit>(can-catch.md:1051),
// repl.MdocSession$App34$.<clinit>(can-catch.md:1025),
// repl.MdocSession$App32$.<clinit>(can-catch.md:957),
// repl.MdocSession$App30$.<clinit>(can-catch.md:867),
// repl.MdocSession$App28$.<clinit>(can-catch.md:790),
// ...
import monix.execution.Scheduler.Implicits.global
val result = fa.runSyncUnsafe()
// result: Either[MyError, Int] = Left(
// value = NonFatalThrowable(
// throwable = java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100]
// )
// )
result match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
// Result: Failed with NonFatalThrowable(java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100])
import java.util.concurrent.{ExecutorService, Executors}
import scala.concurrent.{ExecutionContext, Future, Await}
import scala.concurrent.duration._
import cats._
import cats.data.EitherT
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.Catching._
import effectie.monix.EitherTSupport._
import effectie.concurrent.ExecutorServiceOps
object MyApp {
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
catchNonFatalEitherT(
for {
b <- EitherT(pureOf(divide100By(n)))
c <- eitherTRight[MyError](doSomethingBad(b))
} yield c
)(MyError.nonFatalThrowable).value
def main(args: Array[String]): Unit = {
val executorService: ExecutorService =
Executors.newWorkStealingPool(Runtime.getRuntime.availableProcessors())
implicit val ec: ExecutionContext = ExecutionContext.fromExecutorService(executorService)
try {
val fa = doSomething[Future](-1)
println(fa)
val result = Await.result(fa, 1.second)
println(result)
result match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
} finally {
ExecutorServiceOps.shutdownAndAwaitTermination(executorService, 1.second)
}
}
}
MyApp.main(Array.empty)
// Future(<not completed>)
// Left(NonFatalThrowable(java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100]))
// Result: Failed with NonFatalThrowable(java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100])
NOTE
Use of Id is not recommended as Id means having no Effect. Use it only for some special cases like testing.
import cats._
import cats.data.EitherT
import cats.syntax.all._
import effectie.monix._
import effectie.monix.Effectful._
import effectie.monix.Catching._
import effectie.monix.EitherTSupport._
sealed trait MyError
object MyError {
final case class NonFatalThrowable(throwable: Throwable) extends MyError
case object DivideByZero extends MyError
def nonFatalThrowable(throwable: Throwable): MyError
= NonFatalThrowable(throwable)
def divideByZero: MyError = DivideByZero
}
def divide100By(n: Int): Either[MyError, Int] =
if (n === 0)
MyError.divideByZero.asLeft[Int]
else
(100 / n).asRight[MyError]
def doSomethingBad(n: Int): Int =
if (n < 0)
throw new IllegalArgumentException(s"n cannot be a negative number. [n: $n]")
else
n * 2
def doSomething[F[_]: Fx: CanCatch: Monad](
n: Int
): F[Either[MyError, Int]] =
catchNonFatalEitherT(
for {
b <- EitherT(pureOf(divide100By(n)))
c <- eitherTRight[MyError](doSomethingBad(b))
} yield c
)(MyError.nonFatalThrowable).value
val fa = doSomething[Id](-1)
// fa: Id[Either[MyError, Int]] = Left(
// value = NonFatalThrowable(
// throwable = java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100]
// )
// )
fa match {
case Right(b) =>
println(s"Result is $b")
case Left(a) =>
println(s"Result: Failed with $a")
}
// Result: Failed with NonFatalThrowable(java.lang.IllegalArgumentException: n cannot be a negative number. [n: -100])