Class Either<TLeft, TRight>

Represents a 2-type discriminate union with Left and Right components.

Inheritance

System.Object

Either<TLeft, TRight>

Inherited Members

System.Object.Equals(System.Object, System.Object)

System.Object.GetType()

System.Object.MemberwiseClone()

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.ToString()

Namespace: Maki

Assembly: Maki.dll

Syntax

public sealed class Either<TLeft, TRight>

Type Parameters

Name	Description
TLeft	Left type.
TRight	Right type.

Examples

The following example assigns values to and extracts them from an Either<int, string>.

using Maki;
using System;

namespace Samples
{
    class Program
    {
        static void PrintEither(Either<int, string> either)
        {
            // If either contains the left type (int)
            if (either.IsLeft)
            {
                // Output the left (int) value to the console
                Console.WriteLine(either.GetLeft());
            }
            else // either.IsRight
            {
                // Output the right (string) value to the console
                Console.WriteLine(either.GetRight());
            }
        }

        static void Main(string[] args)
        {
            // Assign an int
            Either<int, string> either = 42;

            // Will print "42"
            PrintEither(either);

            either = "Hello world!";

            // Will print "Hello world!"
            PrintEither(either);
        }
    }
}

Constructors

Either(TLeft)

Creates a new instance of Either from an item of type TLeft.

Declaration

public Either(TLeft left)

Parameters

Type	Name	Description
TLeft	left	Item of type TLeft

Either(TRight)

Creates a new instance of Either from an item of type TRight

Declaration

public Either(TRight right)

Parameters

Type	Name	Description
TRight	right	Item of type TRight

Properties

IsLeft

True if Left is inhabited.

Declaration

public bool IsLeft { get; }

Property Value

Type	Description
System.Boolean

IsRight

True if Right is inhabited.

Declaration

public bool IsRight { get; }

Property Value

Type	Description
System.Boolean

Methods

Equals(Object)

Determines whether the specified object is equal to the current object.

Declaration

public override bool Equals(object obj)

Parameters

Type	Name	Description
System.Object	obj	The object to compare with the current object.

Returns

Type	Description
System.Boolean	True if the objects are equal.

Overrides

System.Object.Equals(System.Object)

GetHashCode()

Returns the hash code for this instance.

Declaration

public override int GetHashCode()

Returns

Type	Description
System.Int32	Hash code.

Overrides

System.Object.GetHashCode()

GetLeft()

Gets the Left component.

Declaration

public TLeft GetLeft()

Returns

Type	Description
TLeft

Exceptions

Type	Condition
System.InvalidCastException	Thrown on get if the inhabiting object is Right.

GetRight()

Gets the Right component.

Declaration

public TRight GetRight()

Returns

Type	Description
TRight

Exceptions

Type	Condition
System.InvalidCastException	Thrown on get if the inhabiting object is Left.

MakeLeft(TLeft)

Creates a new Either explicitly placing the item in the Left component.

Declaration

public static Either<TLeft, TRight> MakeLeft(TLeft item)

Parameters

Type	Name	Description
TLeft	item	Item to place in the Either.

Returns

Type	Description
Either<TLeft, TRight>	Either containing the item.

Remarks

Use this method when both TLeft and TRight are the same.

MakeRight(TRight)

Creates a new Either explicitly placing the item in the Right component.

Declaration

public static Either<TLeft, TRight> MakeRight(TRight item)

Parameters

Type	Name	Description
TRight	item	Item to place in the Either.

Returns

Type	Description
Either<TLeft, TRight>	Either containing the item.

Remarks

Use this method when both TLeft and TRight are the same.

Set(TLeft)

Sets the Left component.

Declaration

public void Set(TLeft left)

Parameters

Type	Name	Description
TLeft	left	Item to place in Either.

Set(TRight)

Sets the Right component.

Declaration

public void Set(TRight right)

Parameters

Type	Name	Description
TRight	right	Item to place in Either.

SetLeft(TLeft)

Explicitly sets the Left component.

Declaration

public void SetLeft(TLeft left)

Parameters

Type	Name	Description
TLeft	left	Item to place in Either.

Remarks

Use whent TLeft and TRight are of the same type.

SetRight(TRight)

Explicitly sets the Right component.

Declaration

public void SetRight(TRight right)

Parameters

Type	Name	Description
TRight	right	Item to place in Either.

Remarks

Use whent TLeft and TRight are of the same type.

Operators

Explicit(Either<TLeft, TRight> to TLeft)

Explicit cast from Either to TLeft.

Declaration

public static explicit operator TLeft(Either<TLeft, TRight> either)

Parameters

Type	Name	Description
Either<TLeft, TRight>	either	Either object to cast.

Returns

Type	Description
TLeft

Exceptions

Type	Condition
System.InvalidCastException	Thrown when the inhabiting object of the either is Right.

Explicit(Either<TLeft, TRight> to TRight)

Explicit cast from Either to TRight.

Declaration

public static explicit operator TRight(Either<TLeft, TRight> either)

Parameters

Type	Name	Description
Either<TLeft, TRight>	either	Either object to cast.

Returns

Type	Description
TRight

Exceptions

Type	Condition
System.InvalidCastException	Thrown when the inhabiting object of the either is Left.

Implicit(TLeft to Either<TLeft, TRight>)

Implicit cast from TLeft item to Either. Creates a new Either.

Declaration

public static implicit operator Either<TLeft, TRight>(TLeft item)

Parameters

Type	Name	Description
TLeft	item	Item to place in Either.

Returns

Type	Description
Either<TLeft, TRight>

Implicit(TRight to Either<TLeft, TRight>)

Implicit cast from TRight item to Either. Creates a new Either.

Declaration

public static implicit operator Either<TLeft, TRight>(TRight item)

Parameters

Type	Name	Description
TRight	item	Item to place in Either.

Returns

Type	Description
Either<TLeft, TRight>