GenTemporal

Semantically block the fiber for the specified duration.

Semantically block the fiber for the specified duration.

Semantically block the fiber for the specified duration.

Semantically block the fiber for the specified duration.

Wait for the specified duration after the execution of fa before returning the result.

Wait for the specified duration after the execution of fa before returning the result.

Wait for the specified duration after the execution of fa before returning the result.

Wait for the specified duration after the execution of fa before returning the result.

Delay the execution of fa by a given duration.

Delay the execution of fa by a given duration.

Delay the execution of fa by a given duration.

Delay the execution of fa by a given duration.

Returns an effect that either completes with the result of the source within the specified time duration or otherwise raises a TimeoutException.

The source is canceled in the event that it takes longer than the specified time duration to complete.

Returns an effect that either completes with the result of the source within the specified time duration or otherwise raises a TimeoutException.

The source is canceled in the event that it takes longer than the specified time duration to complete.

Returns an effect that either completes with the result of the source within the specified time duration or otherwise raises a TimeoutException.

The source is canceled in the event that it takes longer than the specified time duration to complete.

Returns an effect that either completes with the result of the source within the specified time duration or otherwise raises a TimeoutException.

The source is canceled in the event that it takes longer than the specified time duration to complete.

Returns an effect that either completes with the result of the source within the specified time duration or otherwise evaluates the fallback.

The source is canceled in the event that it takes longer than the FiniteDuration to complete, the evaluation of the fallback happening immediately after that.

Returns an effect that either completes with the result of the source within the specified time duration or otherwise evaluates the fallback.

The source is canceled in the event that it takes longer than the FiniteDuration to complete, the evaluation of the fallback happening immediately after that.

Returns an effect that either completes with the result of the source within the specified time duration or otherwise evaluates the fallback.

The source is canceled in the event that it takes longer than the FiniteDuration to complete, the evaluation of the fallback happening immediately after that.

Returns an effect that either completes with the result of the source within the specified time duration or otherwise evaluates the fallback.

The source is canceled in the event that it takes longer than the FiniteDuration to complete, the evaluation of the fallback happening immediately after that.

Alias for productR.

Alias for productR.

Alias for productR.

Alias for productR.

Alias for productL.

Alias for productL.

Alias for productL.

Alias for productL.

Alias for ap.

Alias for ap.

Alias for ap.

Alias for ap.

Replaces the A value in F[A] with the supplied value.

Example:

scala> import cats.Functor
scala> import cats.implicits.catsStdInstancesForList

scala> Functor[List].as(List(1,2,3), "hello")
res0: List[String] = List(hello, hello, hello)

Replaces the A value in F[A] with the supplied value.

Example:

scala> import cats.Functor
scala> import cats.implicits.catsStdInstancesForList

scala> Functor[List].as(List(1,2,3), "hello")
res0: List[String] = List(hello, hello, hello)

Replaces the A value in F[A] with the supplied value.

Example:

scala> import cats.Functor
scala> import cats.implicits.catsStdInstancesForList

scala> Functor[List].as(List(1,2,3), "hello")
res0: List[String] = List(hello, hello, hello)

Replaces the A value in F[A] with the supplied value.

Example:

scala> import cats.Functor
scala> import cats.implicits.catsStdInstancesForList

scala> Functor[List].as(List(1,2,3), "hello")
res0: List[String] = List(hello, hello, hello)

Handle errors by turning them into scala.util.Either values.

If there is no error, then an scala.util.Right value will be returned instead.

All non-fatal errors should be handled by this method.

Handle errors by turning them into scala.util.Either values.

If there is no error, then an scala.util.Right value will be returned instead.

All non-fatal errors should be handled by this method.

Handle errors by turning them into scala.util.Either values.

If there is no error, then an scala.util.Right value will be returned instead.

All non-fatal errors should be handled by this method.

Handle errors by turning them into scala.util.Either values.

If there is no error, then an scala.util.Right value will be returned instead.

All non-fatal errors should be handled by this method.

Similar to attempt, but it only handles errors of type EE.

Similar to attempt, but it only handles errors of type EE.

Similar to attempt, but it only handles errors of type EE.

Similar to attempt, but it only handles errors of type EE.

Similar to attempt, but wraps the result in a cats.data.EitherT for convenience.

Similar to attempt, but wraps the result in a cats.data.EitherT for convenience.

Similar to attempt, but wraps the result in a cats.data.EitherT for convenience.

Similar to attempt, but wraps the result in a cats.data.EitherT for convenience.

Reifies the value or error of the source and performs an effect on the result, then recovers the original value or error back into F.

Note that if the effect returned by f fails, the resulting effect will fail too.

Alias for fa.attempt.flatTap(f).rethrow for convenience.

Example:

scala> import cats.implicits._
scala> import scala.util.{Try, Success, Failure}

scala> def checkError(result: Either[Throwable, Int]): Try[String] = result.fold(_ => Failure(new java.lang.Exception), _ => Success("success"))

scala> val a: Try[Int] = Failure(new Throwable("failed"))
scala> a.attemptTap(checkError)
res0: scala.util.Try[Int] = Failure(java.lang.Exception)

scala> val b: Try[Int] = Success(1)
scala> b.attemptTap(checkError)
res1: scala.util.Try[Int] = Success(1)

Reifies the value or error of the source and performs an effect on the result, then recovers the original value or error back into F.

Note that if the effect returned by f fails, the resulting effect will fail too.

Alias for fa.attempt.flatTap(f).rethrow for convenience.

Example:

scala> import cats.implicits._
scala> import scala.util.{Try, Success, Failure}

scala> def checkError(result: Either[Throwable, Int]): Try[String] = result.fold(_ => Failure(new java.lang.Exception), _ => Success("success"))

scala> val a: Try[Int] = Failure(new Throwable("failed"))
scala> a.attemptTap(checkError)
res0: scala.util.Try[Int] = Failure(java.lang.Exception)

scala> val b: Try[Int] = Success(1)
scala> b.attemptTap(checkError)
res1: scala.util.Try[Int] = Success(1)

Reifies the value or error of the source and performs an effect on the result, then recovers the original value or error back into F.

Note that if the effect returned by f fails, the resulting effect will fail too.

Alias for fa.attempt.flatTap(f).rethrow for convenience.

Example:

scala> import cats.implicits._
scala> import scala.util.{Try, Success, Failure}

scala> def checkError(result: Either[Throwable, Int]): Try[String] = result.fold(_ => Failure(new java.lang.Exception), _ => Success("success"))

scala> val a: Try[Int] = Failure(new Throwable("failed"))
scala> a.attemptTap(checkError)
res0: scala.util.Try[Int] = Failure(java.lang.Exception)

scala> val b: Try[Int] = Success(1)
scala> b.attemptTap(checkError)
res1: scala.util.Try[Int] = Success(1)

Reifies the value or error of the source and performs an effect on the result, then recovers the original value or error back into F.

Note that if the effect returned by f fails, the resulting effect will fail too.

Alias for fa.attempt.flatTap(f).rethrow for convenience.

Example:

scala> import cats.implicits._
scala> import scala.util.{Try, Success, Failure}

scala> def checkError(result: Either[Throwable, Int]): Try[String] = result.fold(_ => Failure(new java.lang.Exception), _ => Success("success"))

scala> val a: Try[Int] = Failure(new Throwable("failed"))
scala> a.attemptTap(checkError)
res0: scala.util.Try[Int] = Failure(java.lang.Exception)

scala> val b: Try[Int] = Success(1)
scala> b.attemptTap(checkError)
res1: scala.util.Try[Int] = Success(1)

Returns a Resource that manages the concurrent execution of a fiber. The inner effect can be used to wait on the outcome of the child fiber; it is effectively a join.

The child fiber is canceled in two cases: either the resource goes out of scope or the parent fiber is canceled. If the child fiber terminates before one of these cases occurs, then cancelation is a no-op. This avoids fiber leaks because the child fiber is always canceled before the parent fiber drops the reference to it.

 // Starts a fiber that continously prints "A".
 // After 10 seconds, the resource scope exits so the fiber is canceled.
 F.background(F.delay(println("A")).foreverM).use { _ =>
   F.sleep(10.seconds)
 }

Returns a Resource that manages the concurrent execution of a fiber. The inner effect can be used to wait on the outcome of the child fiber; it is effectively a join.

The child fiber is canceled in two cases: either the resource goes out of scope or the parent fiber is canceled. If the child fiber terminates before one of these cases occurs, then cancelation is a no-op. This avoids fiber leaks because the child fiber is always canceled before the parent fiber drops the reference to it.

 // Starts a fiber that continously prints "A".
 // After 10 seconds, the resource scope exits so the fiber is canceled.
 F.background(F.delay(println("A")).foreverM).use { _ =>
   F.sleep(10.seconds)
 }

Returns a Resource that manages the concurrent execution of a fiber. The inner effect can be used to wait on the outcome of the child fiber; it is effectively a join.

The child fiber is canceled in two cases: either the resource goes out of scope or the parent fiber is canceled. If the child fiber terminates before one of these cases occurs, then cancelation is a no-op. This avoids fiber leaks because the child fiber is always canceled before the parent fiber drops the reference to it.

 // Starts a fiber that continously prints "A".
 // After 10 seconds, the resource scope exits so the fiber is canceled.
 F.background(F.delay(println("A")).foreverM).use { _ =>
   F.sleep(10.seconds)
 }

Returns a Resource that manages the concurrent execution of a fiber. The inner effect can be used to wait on the outcome of the child fiber; it is effectively a join.

The child fiber is canceled in two cases: either the resource goes out of scope or the parent fiber is canceled. If the child fiber terminates before one of these cases occurs, then cancelation is a no-op. This avoids fiber leaks because the child fiber is always canceled before the parent fiber drops the reference to it.

 // Starts a fiber that continously prints "A".
 // After 10 seconds, the resource scope exits so the fiber is canceled.
 F.background(F.delay(println("A")).foreverM).use { _ =>
   F.sleep(10.seconds)
 }

Races the evaluation of two fibers and returns the result of both.

The following rules describe the semantics of both:

1. If the winner completes with Outcome.Succeeded, the race waits for the loser to complete.
2. If the winner completes with Outcome.Errored, the race raises the error. The loser is canceled.
3. If the winner completes with Outcome.Canceled, the loser and the race are canceled as well.
4. If the loser completes with Outcome.Succeeded, the race returns the successful value of both fibers.
5. If the loser completes with Outcome.Errored, the race returns the error.
6. If the loser completes with Outcome.Canceled, the race is canceled.
7. If the race is canceled before one or both participants complete, then whichever ones are incomplete are canceled.
8. If the race is masked and is canceled because one or both participants canceled, the fiber will block indefinitely.

Races the evaluation of two fibers and returns the result of both.

The following rules describe the semantics of both:

1. If the winner completes with Outcome.Succeeded, the race waits for the loser to complete.
2. If the winner completes with Outcome.Errored, the race raises the error. The loser is canceled.
3. If the winner completes with Outcome.Canceled, the loser and the race are canceled as well.
4. If the loser completes with Outcome.Succeeded, the race returns the successful value of both fibers.
5. If the loser completes with Outcome.Errored, the race returns the error.
6. If the loser completes with Outcome.Canceled, the race is canceled.
7. If the race is canceled before one or both participants complete, then whichever ones are incomplete are canceled.
8. If the race is masked and is canceled because one or both participants canceled, the fiber will block indefinitely.

Races the evaluation of two fibers and returns the result of both.

The following rules describe the semantics of both:

1. If the winner completes with Outcome.Succeeded, the race waits for the loser to complete.
2. If the winner completes with Outcome.Errored, the race raises the error. The loser is canceled.
3. If the winner completes with Outcome.Canceled, the loser and the race are canceled as well.
4. If the loser completes with Outcome.Succeeded, the race returns the successful value of both fibers.
5. If the loser completes with Outcome.Errored, the race returns the error.
6. If the loser completes with Outcome.Canceled, the race is canceled.
7. If the race is canceled before one or both participants complete, then whichever ones are incomplete are canceled.
8. If the race is masked and is canceled because one or both participants canceled, the fiber will block indefinitely.

Races the evaluation of two fibers and returns the result of both.

The following rules describe the semantics of both:

1. If the winner completes with Outcome.Succeeded, the race waits for the loser to complete.
2. If the winner completes with Outcome.Errored, the race raises the error. The loser is canceled.
3. If the winner completes with Outcome.Canceled, the loser and the race are canceled as well.
4. If the loser completes with Outcome.Succeeded, the race returns the successful value of both fibers.
5. If the loser completes with Outcome.Errored, the race returns the error.
6. If the loser completes with Outcome.Canceled, the race is canceled.
7. If the race is canceled before one or both participants complete, then whichever ones are incomplete are canceled.
8. If the race is masked and is canceled because one or both participants canceled, the fiber will block indefinitely.

Races the evaluation of two fibers and returns the Outcome of both. If the race is canceled before one or both participants complete, then then whichever ones are incomplete are canceled.

Races the evaluation of two fibers and returns the Outcome of both. If the race is canceled before one or both participants complete, then then whichever ones are incomplete are canceled.

Races the evaluation of two fibers and returns the Outcome of both. If the race is canceled before one or both participants complete, then then whichever ones are incomplete are canceled.

Races the evaluation of two fibers and returns the Outcome of both. If the race is canceled before one or both participants complete, then then whichever ones are incomplete are canceled.

A pattern for safely interacting with effectful lifecycles.

If acquire completes successfully, use is called. If use succeeds, fails, or is canceled, release is guaranteed to be called exactly once.

acquire is uncancelable. release is uncancelable. use is cancelable by default, but can be masked.

A pattern for safely interacting with effectful lifecycles.

If acquire completes successfully, use is called. If use succeeds, fails, or is canceled, release is guaranteed to be called exactly once.

acquire is uncancelable. release is uncancelable. use is cancelable by default, but can be masked.

A pattern for safely interacting with effectful lifecycles.

If acquire completes successfully, use is called. If use succeeds, fails, or is canceled, release is guaranteed to be called exactly once.

acquire is uncancelable. release is uncancelable. use is cancelable by default, but can be masked.

A pattern for safely interacting with effectful lifecycles.

If acquire completes successfully, use is called. If use succeeds, fails, or is canceled, release is guaranteed to be called exactly once.

acquire is uncancelable. release is uncancelable. use is cancelable by default, but can be masked.

A pattern for safely interacting with effectful lifecycles.

If acquire completes successfully, use is called. If use succeeds, fails, or is canceled, release is guaranteed to be called exactly once.

acquire is uncancelable. release is uncancelable. use is cancelable by default, but can be masked.

A pattern for safely interacting with effectful lifecycles.

If acquire completes successfully, use is called. If use succeeds, fails, or is canceled, release is guaranteed to be called exactly once.

acquire is uncancelable. release is uncancelable. use is cancelable by default, but can be masked.

A pattern for safely interacting with effectful lifecycles.

If acquire completes successfully, use is called. If use succeeds, fails, or is canceled, release is guaranteed to be called exactly once.

acquire is uncancelable. release is uncancelable. use is cancelable by default, but can be masked.

A pattern for safely interacting with effectful lifecycles.

If acquire completes successfully, use is called. If use succeeds, fails, or is canceled, release is guaranteed to be called exactly once.

acquire is uncancelable. release is uncancelable. use is cancelable by default, but can be masked.

A pattern for safely interacting with effectful lifecycles.

If acquire completes successfully, use is called. If use succeeds, fails, or is canceled, release is guaranteed to be called exactly once.

If use succeeds the returned value B is returned. If use returns an exception, the exception is returned.

acquire is uncancelable by default, but can be unmasked. release is uncancelable. use is cancelable by default, but can be masked.

A pattern for safely interacting with effectful lifecycles.

If acquire completes successfully, use is called. If use succeeds, fails, or is canceled, release is guaranteed to be called exactly once.

If use succeeds the returned value B is returned. If use returns an exception, the exception is returned.

acquire is uncancelable by default, but can be unmasked. release is uncancelable. use is cancelable by default, but can be masked.

A pattern for safely interacting with effectful lifecycles.

If acquire completes successfully, use is called. If use succeeds, fails, or is canceled, release is guaranteed to be called exactly once.

If use succeeds the returned value B is returned. If use returns an exception, the exception is returned.

acquire is uncancelable by default, but can be unmasked. release is uncancelable. use is cancelable by default, but can be masked.

A pattern for safely interacting with effectful lifecycles.

If acquire completes successfully, use is called. If use succeeds, fails, or is canceled, release is guaranteed to be called exactly once.

If use succeeds the returned value B is returned. If use returns an exception, the exception is returned.

acquire is uncancelable by default, but can be unmasked. release is uncancelable. use is cancelable by default, but can be masked.

An effect that requests self-cancelation on the current fiber.

In the following example, the fiber requests self-cancelation in a masked region, so cancelation is suppressed until the fiber is completely unmasked. fa will run but fb will not.

 F.uncancelable { _ =>
   F.canceled *> fa
 } *> fb

An effect that requests self-cancelation on the current fiber.

In the following example, the fiber requests self-cancelation in a masked region, so cancelation is suppressed until the fiber is completely unmasked. fa will run but fb will not.

 F.uncancelable { _ =>
   F.canceled *> fa
 } *> fb

An effect that requests self-cancelation on the current fiber.

In the following example, the fiber requests self-cancelation in a masked region, so cancelation is suppressed until the fiber is completely unmasked. fa will run but fb will not.

 F.uncancelable { _ =>
   F.canceled *> fa
 } *> fb

An effect that requests self-cancelation on the current fiber.

In the following example, the fiber requests self-cancelation in a masked region, so cancelation is suppressed until the fiber is completely unmasked. fa will run but fb will not.

 F.uncancelable { _ =>
   F.canceled *> fa
 } *> fb

Often E is Throwable. Here we try to call pure or catch and raise.

Often E is Throwable. Here we try to call pure or catch and raise.

Often E is Throwable. Here we try to call pure or catch and raise.

Often E is Throwable. Here we try to call pure or catch and raise.

Often E is Throwable. Here we try to call pure or catch and raise

Often E is Throwable. Here we try to call pure or catch and raise

Often E is Throwable. Here we try to call pure or catch and raise

Often E is Throwable. Here we try to call pure or catch and raise

Evaluates the specified block, catching exceptions of the specified type. Uncaught exceptions are propagated.

Evaluates the specified block, catching exceptions of the specified type. Uncaught exceptions are propagated.

Evaluates the specified block, catching exceptions of the specified type. Uncaught exceptions are propagated.

Evaluates the specified block, catching exceptions of the specified type. Uncaught exceptions are propagated.

Introduces a fairness boundary that yields control back to the scheduler of the runtime system. This allows the carrier thread to resume execution of another waiting fiber.

Note that cede is merely a hint to the runtime system; implementations have the liberty to interpret this method to their liking as long as it obeys the respective laws. For example, a lawful, but atypical, implementation of this function is F.unit, in which case the fairness boundary is a no-op.

Introduces a fairness boundary that yields control back to the scheduler of the runtime system. This allows the carrier thread to resume execution of another waiting fiber.

Note that cede is merely a hint to the runtime system; implementations have the liberty to interpret this method to their liking as long as it obeys the respective laws. For example, a lawful, but atypical, implementation of this function is F.unit, in which case the fairness boundary is a no-op.

Introduces a fairness boundary that yields control back to the scheduler of the runtime system. This allows the carrier thread to resume execution of another waiting fiber.

Note that cede is merely a hint to the runtime system; implementations have the liberty to interpret this method to their liking as long as it obeys the respective laws. For example, a lawful, but atypical, implementation of this function is F.unit, in which case the fairness boundary is a no-op.

Introduces a fairness boundary that yields control back to the scheduler of the runtime system. This allows the carrier thread to resume execution of another waiting fiber.

Note that cede is merely a hint to the runtime system; implementations have the liberty to interpret this method to their liking as long as it obeys the respective laws. For example, a lawful, but atypical, implementation of this function is F.unit, in which case the fairness boundary is a no-op.

Compose an Applicative[F] and an Applicative[G] into an Applicative[λ[α => F[G[α]]]].

Example:

scala> import cats.implicits._

scala> val alo = Applicative[List].compose[Option]

scala> alo.pure(3)
res0: List[Option[Int]] = List(Some(3))

scala> alo.product(List(None, Some(true), Some(false)), List(Some(2), None))
res1: List[Option[(Boolean, Int)]] = List(None, None, Some((true,2)), None, Some((false,2)), None)

Compose Invariant F[_] and G[_] then produce Invariant[F[G[_]]] using their imap.

Example:

scala> import cats.implicits._
scala> import scala.concurrent.duration._

scala> val durSemigroupList: Semigroup[List[FiniteDuration]] =
    | Invariant[Semigroup].compose[List].imap(Semigroup[List[Long]])(Duration.fromNanos)(_.toNanos)
scala> durSemigroupList.combine(List(2.seconds, 3.seconds), List(4.seconds))
res1: List[FiniteDuration] = List(2 seconds, 3 seconds, 4 seconds)

Compose an Apply[F] and an Apply[G] into an Apply[λ[α => F[G[α]]]].

Example:

scala> import cats.implicits._

scala> val alo = Apply[List].compose[Option]

scala> alo.product(List(None, Some(true), Some(false)), List(Some(2), None))
res1: List[Option[(Boolean, Int)]] = List(None, None, Some((true,2)), None, Some((false,2)), None)

Compose an Applicative[F] and an Applicative[G] into an Applicative[λ[α => F[G[α]]]].

Example:

scala> import cats.implicits._

scala> val alo = Applicative[List].compose[Option]

scala> alo.pure(3)
res0: List[Option[Int]] = List(Some(3))

scala> alo.product(List(None, Some(true), Some(false)), List(Some(2), None))
res1: List[Option[(Boolean, Int)]] = List(None, None, Some((true,2)), None, Some((false,2)), None)

Compose Invariant F[_] and G[_] then produce Invariant[F[G[_]]] using their imap.

Example:

scala> import cats.implicits._
scala> import scala.concurrent.duration._

scala> val durSemigroupList: Semigroup[List[FiniteDuration]] =
    | Invariant[Semigroup].compose[List].imap(Semigroup[List[Long]])(Duration.fromNanos)(_.toNanos)
scala> durSemigroupList.combine(List(2.seconds, 3.seconds), List(4.seconds))
res1: List[FiniteDuration] = List(2 seconds, 3 seconds, 4 seconds)

Compose an Apply[F] and an Apply[G] into an Apply[λ[α => F[G[α]]]].

Example:

scala> import cats.implicits._

scala> val alo = Apply[List].compose[Option]

scala> alo.product(List(None, Some(true), Some(false)), List(Some(2), None))
res1: List[Option[(Boolean, Int)]] = List(None, None, Some((true,2)), None, Some((false,2)), None)

Compose an Applicative[F] and an Applicative[G] into an Applicative[λ[α => F[G[α]]]].

Example:

scala> import cats.implicits._

scala> val alo = Applicative[List].compose[Option]

scala> alo.pure(3)
res0: List[Option[Int]] = List(Some(3))

scala> alo.product(List(None, Some(true), Some(false)), List(Some(2), None))
res1: List[Option[(Boolean, Int)]] = List(None, None, Some((true,2)), None, Some((false,2)), None)

Compose Invariant F[_] and G[_] then produce Invariant[F[G[_]]] using their imap.

Example:

scala> import cats.implicits._
scala> import scala.concurrent.duration._

scala> val durSemigroupList: Semigroup[List[FiniteDuration]] =
    | Invariant[Semigroup].compose[List].imap(Semigroup[List[Long]])(Duration.fromNanos)(_.toNanos)
scala> durSemigroupList.combine(List(2.seconds, 3.seconds), List(4.seconds))
res1: List[FiniteDuration] = List(2 seconds, 3 seconds, 4 seconds)

Compose an Apply[F] and an Apply[G] into an Apply[λ[α => F[G[α]]]].

Example:

scala> import cats.implicits._

scala> val alo = Apply[List].compose[Option]

scala> alo.product(List(None, Some(true), Some(false)), List(Some(2), None))
res1: List[Option[(Boolean, Int)]] = List(None, None, Some((true,2)), None, Some((false,2)), None)

Compose an Applicative[F] and an Applicative[G] into an Applicative[λ[α => F[G[α]]]].

Example:

scala> import cats.implicits._

scala> val alo = Applicative[List].compose[Option]

scala> alo.pure(3)
res0: List[Option[Int]] = List(Some(3))

scala> alo.product(List(None, Some(true), Some(false)), List(Some(2), None))
res1: List[Option[(Boolean, Int)]] = List(None, None, Some((true,2)), None, Some((false,2)), None)

Compose Invariant F[_] and G[_] then produce Invariant[F[G[_]]] using their imap.

Example:

scala> import cats.implicits._
scala> import scala.concurrent.duration._

scala> val durSemigroupList: Semigroup[List[FiniteDuration]] =
    | Invariant[Semigroup].compose[List].imap(Semigroup[List[Long]])(Duration.fromNanos)(_.toNanos)
scala> durSemigroupList.combine(List(2.seconds, 3.seconds), List(4.seconds))
res1: List[FiniteDuration] = List(2 seconds, 3 seconds, 4 seconds)

Compose an Apply[F] and an Apply[G] into an Apply[λ[α => F[G[α]]]].

Example:

scala> import cats.implicits._

scala> val alo = Apply[List].compose[Option]

scala> alo.product(List(None, Some(true), Some(false)), List(Some(2), None))
res1: List[Option[(Boolean, Int)]] = List(None, None, Some((true,2)), None, Some((false,2)), None)

Compose an Applicative[F] and a ContravariantMonoidal[G] into a ContravariantMonoidal[λ[α => F[G[α]]]].

Example:

scala> import cats.kernel.Comparison
scala> import cats.implicits._

// compares strings by alphabetical order
scala> val alpha: Order[String] = Order[String]

// compares strings by their length
scala> val strLength: Order[String] = Order.by[String, Int](_.length)

scala> val stringOrders: List[Order[String]] = List(alpha, strLength)

// first comparison is with alpha order, second is with string length
scala> stringOrders.map(o => o.comparison("abc", "de"))
res0: List[Comparison] = List(LessThan, GreaterThan)

scala> val le = Applicative[List].composeContravariantMonoidal[Order]

// create Int orders that convert ints to strings and then use the string orders
scala> val intOrders: List[Order[Int]] = le.contramap(stringOrders)(_.toString)

// first comparison is with alpha order, second is with string length
scala> intOrders.map(o => o.comparison(12, 3))
res1: List[Comparison] = List(LessThan, GreaterThan)

// create the `product` of the string order list and the int order list
// `p` contains a list of the following orders:
// 1. (alpha comparison on strings followed by alpha comparison on ints)
// 2. (alpha comparison on strings followed by length comparison on ints)
// 3. (length comparison on strings followed by alpha comparison on ints)
// 4. (length comparison on strings followed by length comparison on ints)
scala> val p: List[Order[(String, Int)]] = le.product(stringOrders, intOrders)

scala> p.map(o => o.comparison(("abc", 12), ("def", 3)))
res2: List[Comparison] = List(LessThan, LessThan, LessThan, GreaterThan)

Compose an Applicative[F] and a ContravariantMonoidal[G] into a ContravariantMonoidal[λ[α => F[G[α]]]].

Example:

scala> import cats.kernel.Comparison
scala> import cats.implicits._

// compares strings by alphabetical order
scala> val alpha: Order[String] = Order[String]

// compares strings by their length
scala> val strLength: Order[String] = Order.by[String, Int](_.length)

scala> val stringOrders: List[Order[String]] = List(alpha, strLength)

// first comparison is with alpha order, second is with string length
scala> stringOrders.map(o => o.comparison("abc", "de"))
res0: List[Comparison] = List(LessThan, GreaterThan)

scala> val le = Applicative[List].composeContravariantMonoidal[Order]

// create Int orders that convert ints to strings and then use the string orders
scala> val intOrders: List[Order[Int]] = le.contramap(stringOrders)(_.toString)

// first comparison is with alpha order, second is with string length
scala> intOrders.map(o => o.comparison(12, 3))
res1: List[Comparison] = List(LessThan, GreaterThan)

// create the `product` of the string order list and the int order list
// `p` contains a list of the following orders:
// 1. (alpha comparison on strings followed by alpha comparison on ints)
// 2. (alpha comparison on strings followed by length comparison on ints)
// 3. (length comparison on strings followed by alpha comparison on ints)
// 4. (length comparison on strings followed by length comparison on ints)
scala> val p: List[Order[(String, Int)]] = le.product(stringOrders, intOrders)

scala> p.map(o => o.comparison(("abc", 12), ("def", 3)))
res2: List[Comparison] = List(LessThan, LessThan, LessThan, GreaterThan)

Compose an Applicative[F] and a ContravariantMonoidal[G] into a ContravariantMonoidal[λ[α => F[G[α]]]].

Example:

scala> import cats.kernel.Comparison
scala> import cats.implicits._

// compares strings by alphabetical order
scala> val alpha: Order[String] = Order[String]

// compares strings by their length
scala> val strLength: Order[String] = Order.by[String, Int](_.length)

scala> val stringOrders: List[Order[String]] = List(alpha, strLength)

// first comparison is with alpha order, second is with string length
scala> stringOrders.map(o => o.comparison("abc", "de"))
res0: List[Comparison] = List(LessThan, GreaterThan)

scala> val le = Applicative[List].composeContravariantMonoidal[Order]

// create Int orders that convert ints to strings and then use the string orders
scala> val intOrders: List[Order[Int]] = le.contramap(stringOrders)(_.toString)

// first comparison is with alpha order, second is with string length
scala> intOrders.map(o => o.comparison(12, 3))
res1: List[Comparison] = List(LessThan, GreaterThan)

// create the `product` of the string order list and the int order list
// `p` contains a list of the following orders:
// 1. (alpha comparison on strings followed by alpha comparison on ints)
// 2. (alpha comparison on strings followed by length comparison on ints)
// 3. (length comparison on strings followed by alpha comparison on ints)
// 4. (length comparison on strings followed by length comparison on ints)
scala> val p: List[Order[(String, Int)]] = le.product(stringOrders, intOrders)

scala> p.map(o => o.comparison(("abc", 12), ("def", 3)))
res2: List[Comparison] = List(LessThan, LessThan, LessThan, GreaterThan)

Compose an Applicative[F] and a ContravariantMonoidal[G] into a ContravariantMonoidal[λ[α => F[G[α]]]].

Example:

scala> import cats.kernel.Comparison
scala> import cats.implicits._

// compares strings by alphabetical order
scala> val alpha: Order[String] = Order[String]

// compares strings by their length
scala> val strLength: Order[String] = Order.by[String, Int](_.length)

scala> val stringOrders: List[Order[String]] = List(alpha, strLength)

// first comparison is with alpha order, second is with string length
scala> stringOrders.map(o => o.comparison("abc", "de"))
res0: List[Comparison] = List(LessThan, GreaterThan)

scala> val le = Applicative[List].composeContravariantMonoidal[Order]

// create Int orders that convert ints to strings and then use the string orders
scala> val intOrders: List[Order[Int]] = le.contramap(stringOrders)(_.toString)

// first comparison is with alpha order, second is with string length
scala> intOrders.map(o => o.comparison(12, 3))
res1: List[Comparison] = List(LessThan, GreaterThan)

// create the `product` of the string order list and the int order list
// `p` contains a list of the following orders:
// 1. (alpha comparison on strings followed by alpha comparison on ints)
// 2. (alpha comparison on strings followed by length comparison on ints)
// 3. (length comparison on strings followed by alpha comparison on ints)
// 4. (length comparison on strings followed by length comparison on ints)
scala> val p: List[Order[(String, Int)]] = le.product(stringOrders, intOrders)

scala> p.map(o => o.comparison(("abc", 12), ("def", 3)))
res2: List[Comparison] = List(LessThan, LessThan, LessThan, GreaterThan)

Compose Invariant F[_] and Functor G[_] then produce Invariant[F[G[_]]] using F's imap and G's map.

Example:

scala> import cats.implicits._
scala> import scala.concurrent.duration._

scala> val durSemigroupList: Semigroup[List[FiniteDuration]] =
    | Invariant[Semigroup]
    |   .composeFunctor[List]
    |   .imap(Semigroup[List[Long]])(Duration.fromNanos)(_.toNanos)
scala> durSemigroupList.combine(List(2.seconds, 3.seconds), List(4.seconds))
res1: List[FiniteDuration] = List(2 seconds, 3 seconds, 4 seconds)

Compose Invariant F[_] and Functor G[_] then produce Invariant[F[G[_]]] using F's imap and G's map.

Example:

scala> import cats.implicits._
scala> import scala.concurrent.duration._

scala> val durSemigroupList: Semigroup[List[FiniteDuration]] =
    | Invariant[Semigroup]
    |   .composeFunctor[List]
    |   .imap(Semigroup[List[Long]])(Duration.fromNanos)(_.toNanos)
scala> durSemigroupList.combine(List(2.seconds, 3.seconds), List(4.seconds))
res1: List[FiniteDuration] = List(2 seconds, 3 seconds, 4 seconds)

Compose Invariant F[_] and Functor G[_] then produce Invariant[F[G[_]]] using F's imap and G's map.

Example:

scala> import cats.implicits._
scala> import scala.concurrent.duration._

scala> val durSemigroupList: Semigroup[List[FiniteDuration]] =
    | Invariant[Semigroup]
    |   .composeFunctor[List]
    |   .imap(Semigroup[List[Long]])(Duration.fromNanos)(_.toNanos)
scala> durSemigroupList.combine(List(2.seconds, 3.seconds), List(4.seconds))
res1: List[FiniteDuration] = List(2 seconds, 3 seconds, 4 seconds)

Compose Invariant F[_] and Functor G[_] then produce Invariant[F[G[_]]] using F's imap and G's map.

Example:

scala> import cats.implicits._
scala> import scala.concurrent.duration._

scala> val durSemigroupList: Semigroup[List[FiniteDuration]] =
    | Invariant[Semigroup]
    |   .composeFunctor[List]
    |   .imap(Semigroup[List[Long]])(Duration.fromNanos)(_.toNanos)
scala> durSemigroupList.combine(List(2.seconds, 3.seconds), List(4.seconds))
res1: List[FiniteDuration] = List(2 seconds, 3 seconds, 4 seconds)