opt

Documentation

Index

• Variables
• func Fold[A, B any](o Option[A], m funcs.Mapper[A, B], f0 funcs.Function0[B]) B
• type FMapper
• type Option
  • func FlatMap[T, V any](m Option[T], f FMapper[T, V]) Option[V]
  • func Map[T, V any](m Option[T], f funcs.Mapper[T, V]) Option[V]
  • func None[T any]() Option[T]
  • func OfPtr[T any](t *T) Option[*T]
  • func Some[T any](t T) Option[T]

Variables

var ErrNoneGet = errors.New("none.Get")

Functions

func Fold

func Fold[A, B any](o Option[A], m funcs.Mapper[A, B], f0 funcs.Function0[B]) B

Types

type FMapper

type FMapper[T, V any] funcs.Mapper[T, Option[V]]

type Option

type Option[T any] interface {
	IsDefined() bool
	IsEmpty() bool
	Get() (T, error)
	OrElse(other T) T
	OrDefault() T
	ToSlice() []T
	Filter(p funcs.Predicate[T]) Option[T]
	Foreach(p funcs.Procedure[T]) Option[T]

	// Map method can't change the category; see Map function for that matter.
	Map(mapper funcs.Mapper[T, T]) Option[T]
	// FlatMap method can't change the category; see FlatMap function for that matter.
	FlatMap(mapper FMapper[T, T]) Option[T]
}

Option represents the simplest monad that can contain some value, available for mapping with Map,

or nothing (none).

With that said, Map mapper will never face nil.

func FlatMap

func FlatMap[T, V any](m Option[T], f FMapper[T, V]) Option[V]

func Map

func Map[T, V any](m Option[T], f funcs.Mapper[T, V]) Option[V]

func None

func None[T any]() Option[T]

func OfPtr

func OfPtr[T any](t *T) Option[*T]

func Some

func Some[T any](t T) Option[T]