Console

Effect type agnostic Console with common methods to write and read from the standard console.

For an implementation that uses standard input/output, see Console.io (for Console[IO]) or SyncConsole.stdio (for any F[_]: Sync).

Use it either in a DSL style:

import cats.effect.IO
import cats.effect.Console.io._

val program: IO[Unit] =
  for {
    _ <- putStrLn("Please enter your name: ")
    n <- readLn
    _ <- if (n.nonEmpty) putStrLn(s"Hello $$n!")
         else putError("Name is empty!")
  } yield ()

Or in Tagless Final encoding:

import cats.Monad
import cats.effect._

def myProgram[F[_]: Monad](implicit C: Console[F]): F[Unit] =
  for {
    _ <- C.putStrLn("Please enter your name: ")
    n <- C.readLn
    _ <- if (n.nonEmpty) C.putStrLn(s"Hello $$n!")
         else C.putError("Name is empty!")
  } yield ()

Self Type: Console[F]

Linear Supertypes

ConsoleError[F], ConsoleOut[F], ConsoleIn[F], AnyRef, Any

Abstract Value Members

abstract def putError[A](a: A)(implicit arg0: Show[A]): F[Unit]

Prints a message of type A followed by a new line to the error output using the implicit Show[A] instance.
Prints a message of type A followed by a new line to the error output using the implicit Show[A] instance.

Definition Classes
ConsoleError
abstract def putStr[A](a: A)(implicit arg0: Show[A]): F[Unit]

Prints a message of type A to the console using the implicit Show[A] instance.
Prints a message of type A to the console using the implicit Show[A] instance.

Definition Classes
ConsoleOut
abstract def putStrLn[A](a: A)(implicit arg0: Show[A]): F[Unit]

Prints a message of type A followed by a new line to the console using the implicit Show[A] instance.
Prints a message of type A followed by a new line to the console using the implicit Show[A] instance.

Definition Classes
ConsoleOut
abstract def readLn: F[String]

Reads a line from the console input.
Reads a line from the console input.
returns
a value representing the user's input.

Definition Classes
ConsoleIn

Concrete Value Members

final def !=(arg0: Any): Boolean

Definition Classes
AnyRef → Any
final def ##(): Int

Definition Classes
AnyRef → Any
final def ==(arg0: Any): Boolean

Definition Classes
AnyRef → Any
final def asInstanceOf[T0]: T0

Definition Classes
Any
def clone(): AnyRef

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws( ... )
final def eq(arg0: AnyRef): Boolean

Definition Classes
AnyRef
def equals(arg0: Any): Boolean

Definition Classes
AnyRef → Any
def finalize(): Unit

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws( classOf[java.lang.Throwable] )
final def getClass(): Class[_]

Definition Classes
AnyRef → Any
def hashCode(): Int

Definition Classes
AnyRef → Any
final def isInstanceOf[T0]: Boolean

Definition Classes
Any
def mapK[G[_]](fk: ~>[F, G]): Console[G]

Transforms this console using a FunctionK.
Transforms this console using a FunctionK.

Definition Classes
Console → ConsoleError → ConsoleOut → ConsoleIn
final def ne(arg0: AnyRef): Boolean

Definition Classes
AnyRef
final def notify(): Unit

Definition Classes
AnyRef
final def notifyAll(): Unit

Definition Classes
AnyRef
def putError(str: String): F[Unit]

Prints a message to the error output.
Prints a message to the error output.

Definition Classes
ConsoleError
def putStr(str: String): F[Unit]

Prints a message to the console.
Prints a message to the console.

Definition Classes
ConsoleOut
def putStrLn(str: String): F[Unit]

Prints a message to the console followed by a new line.
Prints a message to the console followed by a new line.

Definition Classes
ConsoleOut
final def synchronized[T0](arg0: ⇒ T0): T0

Definition Classes
AnyRef
def toString(): String

Definition Classes
AnyRef → Any
final def wait(): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )
final def wait(arg0: Long, arg1: Int): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )
final def wait(arg0: Long): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )

Related Docs: object Console | package effect

trait Console[F[_]] extends ConsoleIn[F] with ConsoleOut[F] with ConsoleError[F]

Abstract Value Members

abstract def putError[A](a: A)(implicit arg0: Show[A]): F[Unit]

abstract def putStr[A](a: A)(implicit arg0: Show[A]): F[Unit]

abstract def putStrLn[A](a: A)(implicit arg0: Show[A]): F[Unit]

abstract def readLn: F[String]

Concrete Value Members

final def !=(arg0: Any): Boolean

final def ##(): Int

final def ==(arg0: Any): Boolean

final def asInstanceOf[T0]: T0

def clone(): AnyRef

final def eq(arg0: AnyRef): Boolean

def equals(arg0: Any): Boolean

def finalize(): Unit

final def getClass(): Class[_]

def hashCode(): Int

final def isInstanceOf[T0]: Boolean

def mapK[G[_]](fk: ~>[F, G]): Console[G]

final def ne(arg0: AnyRef): Boolean

final def notify(): Unit

final def notifyAll(): Unit

def putError(str: String): F[Unit]

def putStr(str: String): F[Unit]

def putStrLn(str: String): F[Unit]

final def synchronized[T0](arg0: ⇒ T0): T0

def toString(): String

final def wait(): Unit

final def wait(arg0: Long, arg1: Int): Unit

final def wait(arg0: Long): Unit

Inherited from ConsoleError[F]

Inherited from ConsoleOut[F]

Inherited from ConsoleIn[F]

Inherited from AnyRef

Inherited from Any

Ungrouped