either

Documentation

Index

• func Exists[L, R any](predicate func(right R) bool) func(Either[L, R]) bool
• func FromOption[L, R any](onNone func() L) func(o opt.Option[R]) Either[L, R]
• func FromPredicate[L, R any](predicate func(value R) bool, onLeft func() L) func(R) Either[L, R]
• func GetOrElse[L, R any](onLeft func(left L) R) func(Either[L, R]) R
• func IsLeft[L, R any](e Either[L, R]) bool
• func IsRight[L, R any](e Either[L, R]) bool
• func Map[L, R, T any](onRight func(right R) T) func(Either[L, R]) Either[L, T]
• func MapLeft[L, R, T any](fn func(left L) T) func(Either[L, R]) Either[T, R]
• func Match[L, R, T any](onLeft func(left L) T, onRight func(right R) T) func(Either[L, R]) T
• type Either
  • func Flatten[L, R any](e Either[L, Either[L, R]]) Either[L, R]
  • func FromError[R any](value R, e error) Either[error, R]
  • func FromErrorFn[R any](fn func() (value R, e error)) Either[error, R]
  • func Left[L, R any](value L) Either[L, R]
  • func Right[L, R any](value R) Either[L, R]

Functions

func Exists

func Exists[L, R any](predicate func(right R) bool) func(Either[L, R]) bool

Returns `false` if `Left` or returns the boolean result of the application of the given predicate to the `Right` value

func FromOption

func FromOption[L, R any](onNone func() L) func(o opt.Option[R]) Either[L, R]

Constructor of Either from an Option. Returns a Left in case of None storing the callback return value as the error argument Returns a Right in case of Some with the option value.

func FromPredicate

func FromPredicate[L, R any](predicate func(value R) bool, onLeft func() L) func(R) Either[L, R]

Constructor of Either from a predicate. Returns a Left if the predicate function over the value return false. Returns a Right if the predicate function over the value return true.

func GetOrElse

func GetOrElse[L, R any](onLeft func(left L) R) func(Either[L, R]) R

Extracts the value out of the Either, if it exists. Otherwise returns the result of the callback function that takes the error as argument.

func IsLeft

func IsLeft[L, R any](e Either[L, R]) bool

Helper to check if the Either has an error

func IsRight

func IsRight[L, R any](e Either[L, R]) bool

Helper to check if the Either has a value

func Map

func Map[L, R, T any](onRight func(right R) T) func(Either[L, R]) Either[L, T]

Map over the Either value if it exists. Otherwise return the Either itself

func MapLeft

func MapLeft[L, R, T any](fn func(left L) T) func(Either[L, R]) Either[T, R]

Map over the Either error if it exists. Otherwise return the Either with the new error type

func Match

func Match[L, R, T any](onLeft func(left L) T, onRight func(right R) T) func(Either[L, R]) T

Extracts the value out of the Either. Returns a new type running the succes or error callbacks which are taking respectively the error or value as an argument.

Types

type Either

type Either[L, R any] struct {
	// contains filtered or unexported fields
}

Base struct

func Flatten

func Flatten[L, R any](e Either[L, Either[L, R]]) Either[L, R]

Removes one level of nesting. Returns its bound argument into the outer level.

func FromError

func FromError[R any](value R, e error) Either[error, R]

Constructor of Either from any couple of mutually exclusive `value` and `error`. Returns a Left in case we have an error, Right if we have a value and error is nil.

func FromErrorFn

func FromErrorFn[R any](fn func() (value R, e error)) Either[error, R]

Constructor of Either from any lazy function that returns a couple of mutually exclusive `value` and `error`. Returns a Left in case we have a return error, Right if we have return value and error is nil.

func Left

func Left[L, R any](value L) Either[L, R]

Constructor for Either with a value

func Right

func Right[L, R any](value R) Either[L, R]

Constructor for Either with an error