Resource

Resource data constructor that wraps an effect allocating a resource, along with its finalizers.

Resource data constructor that encodes the flatMap operation.

Resource data constructor that suspends the evaluation of another resource value.

Newtype encoding for a Resource datatype that has a cats.Applicative capable of doing parallel processing in ap and map2, needed for implementing cats.Parallel.

Helpers are provided for converting back and forth in Par.apply for wrapping any IO value and Par.unwrap for unwrapping.

The encoding is based on the "newtypes" project by Alexander Konovalov, chosen because it's devoid of boxing issues and a good choice until opaque types will land in Scala. alexknvl/newtypes.

Creates a resource from an allocating effect.

Creates a resource from an allocating effect, with a finalizer that is able to distinguish between exit cases.

Lifts an applicative into a resource. The resource has a no-op release. Preserves interruptibility of fa.

Creates a Resource by wrapping a Java AutoCloseable.

Example:

 import cats.effect._
 import scala.io.Source

 def reader[F[_]](data: String)(implicit F: Sync[F]): Resource[F, Source] =
   Resource.fromAutoCloseable(F.delay {
     Source.fromString(data)
   })

Creates a Resource by wrapping a Java AutoCloseable which is blocking in its adquire and close operations.

Example:

 import java.io._
 import cats.effect._

 def reader[F[_]](file: File, blocker: Blocker)(implicit F: Sync[F], cs: ContextShift[F]): Resource[F, BufferedReader] =
   Resource.fromAutoCloseableBlocking(blocker)(F.delay {
     new BufferedReader(new FileReader(file))
   })

Lifts an applicative into a resource as a FunctionK. The resource has a no-op release.

Creates a resource from an acquiring effect and a release function.

This builder mirrors the signature of Bracket.bracket.

Creates a resource from an acquiring effect and a release function that can discriminate between different exit cases.

This builder mirrors the signature of Bracket.bracketCase.

Lifts a pure value into a resource. The resource has a no-op release.

Given a Resource suspended in F[_], lifts it in the Resource context.

Implementation for the tailRecM operation, as described via the cats.Monad type class.

Creates a Resource by wrapping a Java Destroyable.

Example:

 import java.security.KeyStore.PasswordProtection
 import cats.effect._
 import cats.syntax.all._

 def passwordProtection[F[_]](getPassword: F[Array[Char]])(implicit F: Sync[F]): Resource[F, PasswordProtection] =
   Resource.fromDestroyable(
     getPassword.map(new PasswordProtection(_))
   )