Loyc.Either< L, R > Struct Template Reference

Holds a single value of one of two types (L or R). More...

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Source file:

• /Core/Loyc.Interfaces/Concrete/Either.cs

Inheritance diagram for Loyc.Either< L, R >:

Remarks

Holds a single value of one of two types (L or R).

For efficiency, this is a struct, but this makes it possible to default-construct it. In that case its value will be default(R).

Public fields
Maybe< L >	Left => _hasLeft ? _left : new Maybe<L>()
Maybe< R >	Right => _hasLeft ? new Maybe<R>() : _right
object	Value => _hasLeft ? (object?)_left : _right
int ITuple.	Length => 2
object	this[int index]
IMaybe< L > IEither< L, R >.	Left => Left
IMaybe< R > IEither< L, R >.	Right => Right

Public Member Functions
static Either< L, R >	R (value)
static Either< L, R >	R (value)
	Either (L value)
	Either (R value)
Either< L2, R2 >	Select< L2, R2 > (Func< L, L2 > selectL, Func< R, R2 > selectR)
	Converts an Either to another with different types. More...
Either< L2, R2 > R2(selectL(_left)) Either< L2, R >	MapLeft< L2 > (Func< L, L2 > selectL)
	Transforms Left with the given selector, if Left.HasValue. Otherwise, returns Right unchanged. More...
Either< L2, R2 > R2(selectL(_left)) Either< L2, R > R(selectL(_left)) Either< L, R2 >	MapRight< R2 > (Func< R, R2 > selectR)
	Transforms Right with the given selector, if Right.HasValue. Otherwise, returns Left unchanged. More...
Either< L2, R2 > R2(selectL(_left)) Either< L2, R > R(selectL(_left)) Either< L, R2 > R2(selectR(_right)) T	Match< T > (Func< L, T > selectL, Func< R, T > selectR)
	Transforms Left or Right with exactly one of the two functions given, returning whatever that function returns. More...
Either< L, R >	IfLeft (Action< L > actionL)
	Runs actionL if Left.HasValue. Equivalent to Left.Then(actionL), but also returns this. More...
Either< L, R >	IfRight (Action< R > actionR)
	Runs actionR if Right.HasValue. Equivalent to Right.Then(actionL), but also returns this. More...
override string	ToString ()
override int	GetHashCode ()
override bool	Equals (object?obj)
bool	Equals (ITuple?other)
bool	Equals (Either< L, R > other)

Static Public Member Functions
static Either< L, R >	NewLeft (L value)
	Simply calls the constructor. This method exists to make it possible to construct an Either when both types are the same. More...
static Either< L, R >	NewRight (R value)
	Simply calls the constructor. This method exists to make it possible to construct an Either when both types are the same. More...
static implicit	operator Either< L, R > (L value)
static implicit	operator Either< L, R > (R value)
static Either< L, R >	From< L2, R2 > (Either< L2, R2 > x)
	Does an upcast, e.g. Either{string,ArgumentException} to Either{object,Exception}. C# does not allow defining conversion operators to take generic parameters, so you'll have to put up with this hassle instead. More...

Additional Inherited Members
Properties inherited from Loyc.IEither< out L, out R >
IMaybe< L >	Left [get]
IMaybe< R >	Right [get]
Properties inherited from Loyc.IValue< out T >
T	Value [get]

Member Function Documentation

static Either<L, R> Loyc.Either< L, R >.From< L2, R2 > ( Either< L2, R2 >  x )

static

Does an upcast, e.g. Either{string,ArgumentException} to Either{object,Exception}. C# does not allow defining conversion operators to take generic parameters, so you'll have to put up with this hassle instead.

Sadly, automatically upcasting value types to reference types doesn't seem possible.

Type Constraints

L2	:	L
R2	:	R
R2	:	new
R2	:	Either
R2	:	L
R2	:	R
R2	:	x._hasLeft
R2	:	x._left
R2	:	x._right

Either<L, R> Loyc.Either< L, R >.IfLeft ( Action< L >  actionL )

inline

Runs actionL if Left.HasValue. Equivalent to Left.Then(actionL), but also returns this.

Either<L, R> Loyc.Either< L, R >.IfRight ( Action< R >  actionR )

inline

Runs actionR if Right.HasValue. Equivalent to Right.Then(actionL), but also returns this.

Either<L2, R2> R2 (selectL(_left)) Either<L2, R> Loyc.Either< L, R >.MapLeft< L2 >

(

Func< L, L2 >

selectL

)

Transforms Left with the given selector, if Left.HasValue. Otherwise, returns Right unchanged.

Either<L2, R2> R2 (selectL(_left)) Either<L2, R> R (selectL(_left)) Either<L, R2> Loyc.Either< L, R >.MapRight< R2 >

(

Func< R, R2 >

selectR

)

Transforms Right with the given selector, if Right.HasValue. Otherwise, returns Left unchanged.

Either<L2, R2> R2 (selectL(_left)) Either<L2, R> R (selectL(_left)) Either<L, R2> R2 (selectR(_right)) T Loyc.Either< L, R >.Match< T >	(	Func< L, T >	selectL,
		Func< R, T >	selectR
	)

Transforms Left or Right with exactly one of the two functions given, returning whatever that function returns.

static Either<L, R> Loyc.Either< L, R >.NewLeft ( L  value )

static

Simply calls the constructor. This method exists to make it possible to construct an Either when both types are the same.

static Either<L, R> Loyc.Either< L, R >.NewRight ( R  value )

static

Simply calls the constructor. This method exists to make it possible to construct an Either when both types are the same.

Either<L2, R2> Loyc.Either< L, R >.Select< L2, R2 >	(	Func< L, L2 >	selectL,
		Func< R, R2 >	selectR
	)

Converts an Either to another with different types.

Member Data Documentation

object Loyc.Either< L, R >.this[int index]

Initial value:

=> 
            index == 0 ? Left : 
            index == 1 ? (object)Right : 
            throw new IndexOutOfRangeException()