cats-effect-kernel/cats.effect.kernel/Resource

Resource

cats.effect.kernel.Resource

See theResource companion class

object Resource

Attributes

Companion: class
Source: Resource.scala
Graph
Supertypes: trait Sum

trait Mirror

class Object

trait Matchable

class Any
Self type: Resource.type

Members list

Type members

Classlikes

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

Attributes

Source: Resource.scala
Supertypes: trait Product

trait Equals

class Resource[F, A]

trait Serializable

class Object

trait Matchable

class Any
Show all

Resource data constructor that encodes the flatMap operation.

Attributes

Source: Resource.scala
Supertypes: trait Product

trait Equals

class Resource[F, A]

trait Serializable

class Object

trait Matchable

class Any
Show all

Attributes

Source: Resource.scala
Supertypes: trait Product

trait Equals

class Resource[F, A]

trait Serializable

class Object

trait Matchable

class Any
Show all

Attributes

Companion: trait
Source: Resource.scala
Supertypes: trait Sum

trait Mirror

class Object

trait Matchable

class Any
Self type: ExitCase.type

Type for signaling the exit condition of an effectful computation, that may either succeed, fail with an error or get canceled.

The types of exit signals are:

Succeeded: for successful completion
Errored: for termination in failure
Canceled: for abortion

Attributes

Companion: object
Source: Resource.scala
Supertypes: trait Serializable

trait Product

trait Equals

class Object

trait Matchable

class Any
Show all
Known subtypes: object Canceled.type

class Errored

object Succeeded.type

Attributes

Source: Resource.scala
Supertypes: class AnyVal

trait Matchable

class Any

Attributes

Source: Resource.scala
Supertypes: trait Product

trait Equals

class Resource[F, A]

trait Serializable

class Object

trait Matchable

class Any
Show all

Types

Attributes

Source: Resource.scala

Inherited types

The names of the product elements

Attributes

Inherited from:: Mirror
Source: Mirror.scala

The name of the type

Attributes

Inherited from:: Mirror
Source: Mirror.scala

Value members

Concrete methods

Creates a resource from an allocating effect.

Type parameters

A: the type of the resource
F: the effect type in which the resource is acquired and released

Value parameters

resource: an effect that returns a tuple of a resource and an effect to release it

Attributes

See also: make for a version that separates the needed resource with its finalizer tuple in two parameters
Source: Resource.scala

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

Type parameters

A: the type of the resource
F: the effect type in which the resource is acquired and released

Value parameters

resource: an effect that returns a tuple of a resource and an effectful function to release it

Attributes

See also: makeCase for a version that separates the needed resource with its finalizer tuple in two parameters
Source: Resource.scala

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

The action takes a Poll[F] to allow for interruptible acquires, which is most often useful when acquiring lock-like structure: it should be possible to interrupt a fiber waiting on a lock, but if it does get acquired, release need to be guaranteed.

Note that in this case the acquire action should know how to cleanup after itself in case it gets canceled, since Resource will only guarantee release when acquire succeeds (and when the actions in use or flatMap fail, succeed, or get canceled)

TODO make sure this api, which is more general than makeFull, doesn't allow for interruptible releases

Type parameters

A: the type of the resource
F: the effect type in which the resource is acquired and released

Value parameters

resource: an effect that returns a tuple of a resource and an effectful function to release it, where acquisition can potentially be interrupted

Attributes

See also: makeFull for a version that separates the needed resource with its finalizer tuple in two parameters
Source: Resource.scala

Allocates two resources concurrently, and combines their results in a tuple.

Attributes

Source: Resource.scala

Attributes

Source: Resource.scala

Attributes

Source: Resource.scala

Attributes

Source: Resource.scala

Attributes

Source: Resource.scala

Lifts an applicative into a resource.

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

Value parameters

fa: the value to lift into a resource

Attributes

Source: Resource.scala

Attributes

Source: Resource.scala

Creates a Resource by wrapping a Java AutoCloseable.

In most real world cases, implementors of AutoCloseable are blocking as well, so the close action runs in the blocking context.

Type parameters

A: the type of the autocloseable resource
F: the type of the effect

Value parameters

F: the effect type in which the resource was acquired and will be released
acquire: The effect with the resource to acquire.

Attributes

Returns

a Resource that will automatically close after use

Example

import cats.effect._
import scala.io.Source
def reader(data: String): Resource[IO, Source] =
  Resource.fromAutoCloseable(IO.blocking {
    Source.fromString(data)
  })

import cats.effect._
import scala.io.Source
def reader[F[_]](data: String)(implicit F: Sync[F]): Resource[F, Source] =
  Resource.fromAutoCloseable(F.blocking {
    Source.fromString(data)
  })

Source

Resource.scala

Lifts an applicative into a resource as a FunctionK.

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

Attributes

Source: Resource.scala

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

Type parameters

A: the type of the resource
F: the effect type in which the resource is acquired and released

Value parameters

acquire: an effect to acquire a resource
release: a function to effectfully release the resource returned by acquire

Attributes

Source: Resource.scala

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

Type parameters

A: the type of the resource
F: the effect type in which the resource is acquired and released

Value parameters

acquire: a function to effectfully acquire a resource
release: a function to effectfully release the resource returned by acquire

Attributes

Source: Resource.scala

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

The acquiring effect takes a Poll[F] to allow for cancelable acquires, which is most often useful when acquiring lock-like structures: it should be possible to interrupt a fiber waiting on a lock, but if it does get acquired, release need to be guaranteed.