izumi.functional.bio.impl.MiniBIO.scala Maven / Gradle / Ivy
package izumi.functional.bio.impl
import izumi.functional.bio.Exit.Trace
import izumi.functional.bio.data.{Morphism2, RestoreInterruption2}
import izumi.functional.bio.impl.MiniBIO.Fail
import izumi.functional.bio.{BlockingIO2, Exit, IO2}
import scala.annotation.{nowarn, tailrec}
import scala.language.implicitConversions
/**
* A lightweight dependency-less implementation of the [[izumi.functional.bio.IO2]] interface,
* analogous in purpose with [[cats.effect.kernel.SyncIO]]
*
* Sync-only, not interruptible, not async.
* For internal use. Prefer ZIO or cats-bio in production.
*
* This is safe to run in a synchronous environment,
* Use MiniBIO.autoRun to gain access to components polymorphic over [[izumi.functional.bio.IO2]]
* in a synchronous environment.
*
* {{{
* final class MyBIOClock[F[+_, +_]: IO2]() {
* val nanoTime: F[Nothing, Long] = IO2(System.nanoTime())
* }
*
* import MiniBIO.autoRun._
*
* val time: Long = new MyBIOClock().nanoTime
* println(time)
* }}}
*/
sealed trait MiniBIO[+E, +A] {
final def run(): Exit.Uninterrupted[E, A] = {
final class Catcher[E0, A0, E1, B](
val recover: Exit.FailureUninterrupted[E0] => MiniBIO[E1, B],
f: A0 => MiniBIO[E1, B],
) extends (A0 => MiniBIO[E1, B]) {
override def apply(a: A0): MiniBIO[E1, B] = f(a)
}
// FIXME: Scala 3.1.4 bug: false unexhaustive match warning
@nowarn("msg=pattern case: MiniBIO.FlatMap")
@tailrec def runner(op: MiniBIO[Any, Any], stack: List[Any => MiniBIO[Any, Any]]): Exit.Uninterrupted[Any, Any] = op match {
case MiniBIO.FlatMap(io, f) =>
runner(io, f.asInstanceOf[Any => MiniBIO[Any, Any]] :: stack)
case MiniBIO.Redeem(io, err, succ) =>
runner(io, new Catcher(err, succ).asInstanceOf[Any => MiniBIO[Any, Any]] :: stack)
case MiniBIO.Sync(a) =>
val exit =
try { a() }
catch {
case t: Throwable =>
Exit.Termination(t, Trace.ThrowableTrace(t))
}
exit match {
case Exit.Success(value) =>
stack match {
case flatMap :: stackRest =>
val nextIO =
try { flatMap(value) }
catch {
case t: Throwable =>
Fail.terminate(t)
}
runner(nextIO, stackRest)
case Nil =>
exit
}
case failure: Exit.FailureUninterrupted[?] =>
runner(Fail.halt(failure), stack)
}
case MiniBIO.Fail(e) =>
val err =
try e()
catch {
case t: Throwable =>
Exit.Termination(t, Trace.ThrowableTrace(t))
}
val catcher = stack.dropWhile(!_.isInstanceOf[Catcher[?, ?, ?, ?]])
catcher match {
case value :: stackRest =>
runner(value.asInstanceOf[Catcher[Any, Any, Any, Any]].recover(err), stackRest)
case Nil =>
err
}
}
runner(this, Nil).asInstanceOf[Exit.Uninterrupted[E, A]]
}
}
object MiniBIO {
object autoRun {
implicit def autoRunAlways[A](f: MiniBIO[Throwable, A]): A = f.run() match {
case Exit.Success(value) =>
value
case failure: Exit.FailureUninterrupted[Throwable] =>
throw failure.toThrowable
}
implicit def BIOMiniBIOHighPriority: IO2[MiniBIO] = BIOMiniBIO
}
final case class Fail[+E](e: () => Exit.FailureUninterrupted[E]) extends MiniBIO[E, Nothing]
object Fail {
def terminate(t: Throwable): Fail[Nothing] = Fail(() => Exit.Termination(t, Trace.ThrowableTrace(t)))
def halt[E](e: => Exit.FailureUninterrupted[E]): Fail[E] = Fail(() => e)
}
final case class Sync[+E, +A](a: () => Exit.Uninterrupted[E, A]) extends MiniBIO[E, A]
final case class FlatMap[E, A, +E1 >: E, +B](io: MiniBIO[E, A], f: A => MiniBIO[E1, B]) extends MiniBIO[E1, B]
final case class Redeem[E, A, +E1, +B](io: MiniBIO[E, A], err: Exit.FailureUninterrupted[E] => MiniBIO[E1, B], succ: A => MiniBIO[E1, B]) extends MiniBIO[E1, B]
implicit val BIOMiniBIO: IO2[MiniBIO] & BlockingIO2[MiniBIO] = new IO2[MiniBIO] with BlockingIO2[MiniBIO] {
override def pure[A](a: A): MiniBIO[Nothing, A] = sync(a)
override def flatMap[E, A, B](r: MiniBIO[E, A])(f: A => MiniBIO[E, B]): MiniBIO[E, B] = FlatMap(r, f)
override def fail[E](v: => E): MiniBIO[E, Nothing] = Fail(() => Exit.Error(v, Trace.forTypedError(v)))
override def terminate(v: => Throwable): MiniBIO[Nothing, Nothing] = Fail.terminate(v)
override def sendInterruptToSelf: MiniBIO[Nothing, Unit] = unit
override def syncThrowable[A](effect: => A): MiniBIO[Throwable, A] = Sync {
() =>
try {
Exit.Success(effect)
} catch { case e: Throwable => Exit.Error(e, Trace.ThrowableTrace(e)) }
}
override def sync[A](effect: => A): MiniBIO[Nothing, A] = Sync(() => Exit.Success(effect))
override def redeem[E, A, E2, B](r: MiniBIO[E, A])(err: E => MiniBIO[E2, B], succ: A => MiniBIO[E2, B]): MiniBIO[E2, B] = {
Redeem[E, A, E2, B](
r,
{
case e: Exit.Termination => Fail.halt(e)
case Exit.Error(e, _) => err(e)
},
succ,
)
}
override def catchAll[E, A, E2](r: MiniBIO[E, A])(f: E => MiniBIO[E2, A]): MiniBIO[E2, A] = redeem(r)(f, pure)
override def bracketCase[E, A, B](acquire: MiniBIO[E, A])(release: (A, Exit[E, B]) => MiniBIO[Nothing, Unit])(use: A => MiniBIO[E, B]): MiniBIO[E, B] = {
// does not propagate error raised in release if `use` failed, in that case only error from `use` is preserved
flatMap(acquire)(
a =>
Redeem[E, B, E, B](
io = use(a),
err = e => Redeem[Nothing, Unit, E, Nothing](release(a, e), err = _ => Fail(() => e), succ = _ => Fail(() => e)),
succ = v => map(release(a, Exit.Success(v)))(_ => v),
)
)
}
override def sandbox[E, A](r: MiniBIO[E, A]): MiniBIO[Exit.FailureUninterrupted[E], A] = {
Redeem[E, A, Exit.FailureUninterrupted[E], A](r, e => fail(e), pure)
}
override def traverse[E, A, B](l: Iterable[A])(f: A => MiniBIO[E, B]): MiniBIO[E, List[B]] = {
val x = l.foldLeft(pure(Nil): MiniBIO[E, List[B]]) {
(acc, a) =>
flatMap(acc)(list => map(f(a))(_ :: list))
}
map(x)(_.reverse)
}
override def shiftBlocking[E, A](f: MiniBIO[E, A]): MiniBIO[E, A] = f
override def syncBlocking[A](f: => A): MiniBIO[Throwable, A] = sync(f)
override def syncInterruptibleBlocking[A](f: => A): MiniBIO[Throwable, A] = sync(f)
override def uninterruptible[E, A](r: MiniBIO[E, A]): MiniBIO[E, A] = r
override def uninterruptibleExcept[E, A](r: RestoreInterruption2[MiniBIO] => MiniBIO[E, A]): MiniBIO[E, A] = r(Morphism2(identity(_)))
override def bracketExcept[E, A, B](
acquire: RestoreInterruption2[MiniBIO] => MiniBIO[E, A]
)(release: (A, Exit[E, B]) => MiniBIO[Nothing, Unit]
)(use: A => MiniBIO[E, B]
): MiniBIO[E, B] = bracketCase(acquire(Morphism2(identity(_))))(release)(use)
}
}
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