Sync

Like Sync.delay but intended for thread blocking operations. blocking will shift the execution of the blocking operation to a separate threadpool to avoid blocking on the main execution context. See the thread-model documentation for more information on why this is necesary.

Sync[F].blocking(scala.io.Source.fromFile("path").mkString)

Like Sync.delay but intended for thread blocking operations. blocking will shift the execution of the blocking operation to a separate threadpool to avoid blocking on the main execution context. See the thread-model documentation for more information on why this is necesary.

Sync[F].blocking(scala.io.Source.fromFile("path").mkString)

Like Sync.delay but intended for thread blocking operations. blocking will shift the execution of the blocking operation to a separate threadpool to avoid blocking on the main execution context. See the thread-model documentation for more information on why this is necesary.

Sync[F].blocking(scala.io.Source.fromFile("path").mkString)

Like Sync.delay but intended for thread blocking operations. blocking will shift the execution of the blocking operation to a separate threadpool to avoid blocking on the main execution context. See the thread-model documentation for more information on why this is necesary.

Sync[F].blocking(scala.io.Source.fromFile("path").mkString)

Like Sync.delay but intended for thread blocking operations. blocking will shift the execution of the blocking operation to a separate threadpool to avoid blocking on the main execution context. See the thread-model documentation for more information on why this is necesary.

Sync[F].blocking(scala.io.Source.fromFile("path").mkString)

Suspends the evaluation of an F[_] reference.

Equivalent to FlatMap.flatten for pure expressions, the purpose of this function is to suspend side effects in F[_].

Suspends the evaluation of an F[_] reference.

Equivalent to FlatMap.flatten for pure expressions, the purpose of this function is to suspend side effects in F[_].

Suspends the evaluation of an F[_] reference.

Equivalent to FlatMap.flatten for pure expressions, the purpose of this function is to suspend side effects in F[_].

Suspends the evaluation of an F[_] reference.

Equivalent to FlatMap.flatten for pure expressions, the purpose of this function is to suspend side effects in F[_].

Suspends the evaluation of an F[_] reference.

Equivalent to FlatMap.flatten for pure expressions, the purpose of this function is to suspend side effects in F[_].

The synchronous FFI - lifts any by-name parameter into the F[_] context.

Equivalent to Applicative.pure for pure expressions, the purpose of this function is to suspend side effects in F.

The synchronous FFI - lifts any by-name parameter into the F[_] context.

Equivalent to Applicative.pure for pure expressions, the purpose of this function is to suspend side effects in F.

The synchronous FFI - lifts any by-name parameter into the F[_] context.

Equivalent to Applicative.pure for pure expressions, the purpose of this function is to suspend side effects in F.

The synchronous FFI - lifts any by-name parameter into the F[_] context.

Equivalent to Applicative.pure for pure expressions, the purpose of this function is to suspend side effects in F.

The synchronous FFI - lifts any by-name parameter into the F[_] context.

Equivalent to Applicative.pure for pure expressions, the purpose of this function is to suspend side effects in F.

Like Sync.blocking but will attempt to abort the blocking operation using thread interrupts in the event of cancelation.

Like Sync.blocking but will attempt to abort the blocking operation using thread interrupts in the event of cancelation.

Like Sync.blocking but will attempt to abort the blocking operation using thread interrupts in the event of cancelation.

Like Sync.blocking but will attempt to abort the blocking operation using thread interrupts in the event of cancelation.

Like Sync.blocking but will attempt to abort the blocking operation using thread interrupts in the event of cancelation.

Yields a value that is guaranteed to be unique ie (F.unique, F.unique).mapN(_ =!= _)

Yields a value that is guaranteed to be unique ie (F.unique, F.unique).mapN(_ =!= _)

Yields a value that is guaranteed to be unique ie (F.unique, F.unique).mapN(_ =!= _)

Yields a value that is guaranteed to be unique ie (F.unique, F.unique).mapN(_ =!= _)

Yields a value that is guaranteed to be unique ie (F.unique, F.unique).mapN(_ =!= _)

Alias for productR.

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 productL.

Alias for ap.

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)

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.

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 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.

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)

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)

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.

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.

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

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

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.

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

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)