cats-docs/cats/Eval/Defer

Defer

sealed abstract class Defer[A](val thunk: () => Eval[A]) extends Eval[A]

Defer is a type of Eval[A] that is used to defer computations which produce Eval[A].

Users should not instantiate Defer instances themselves. Instead, they will be automatically created when needed.

class Eval[A]
class Object
trait Matchable
class Any

Value members

Concrete methods

def memoize: Eval[A]
def value: A

Inherited methods

def flatMap[B](f: A => Eval[B]): Eval[B]

Lazily perform a computation based on an Eval[A], using the function f to produce an Eval[B] given an A.

Lazily perform a computation based on an Eval[A], using the function f to produce an Eval[B] given an A.

This call is stack-safe -- many .flatMap calls may be chained without consumed additional stack during evaluation. It is also written to avoid left-association problems, so that repeated calls to .flatMap will be efficiently applied.

Computation performed in f is always lazy, even when called on an eager (Now) instance.

Inherited from:
Eval
def map[B](f: A => B): Eval[B]

Transform an Eval[A] into an Eval[B] given the transformation function f.

Transform an Eval[A] into an Eval[B] given the transformation function f.

This call is stack-safe -- many .map calls may be chained without consumed additional stack during evaluation.

Computation performed in f is always lazy, even when called on an eager (Now) instance.

Inherited from:
Eval

Concrete fields

val thunk: () => Eval[A]