CSharpx.Maybe< T > Class Template Reference

The Maybe type models an optional value. A value of type Maybe a either contains a value of type a (represented as Just a), or it is empty (represented as Nothing). More...

Inheritance diagram for CSharpx.Maybe< T >:

Public Member Functions
bool	MatchJust (out T value)
	Matches a value returning true and value itself via output parameter.
bool	MatchNothing ()
	Matches an empty value returning true.

Static Public Member Functions
static Maybe< T >	Nothing< T > ()
	Builds the empty case of CSharpx.Maybe.
static Just< T >	Just< T > (T value)
	Builds the case when CSharpx.Maybe contains a value.
static Maybe< T >	Return< T > (T value)
	Inject a value into the monadic CSharpx.Maybe<T> type.
static Maybe< T2 >	Bind< T1, T2 > (Maybe< T1 > maybe, Func< T1, Maybe< T2 > > func)
	Sequentially compose two actions, passing any value produced by the first as an argument to the second.
static Maybe< T2 >	Map< T1, T2 > (Maybe< T1 > maybe, Func< T1, T2 > func)
	Transforms an maybe value by using a specified mapping function.
static Maybe< Tuple< T1, T2 > >	Merge< T1, T2 > (Maybe< T1 > first, Maybe< T2 > second)
	If both maybes contain a value, it merges them into a maybe with a tupled value.
static Maybe< TRight >	FromEither< TLeft, TRight > (Either< TLeft, TRight > either)
	Maps Either Right value to Maybe Just, otherwise Maybe Nothing.

Protected Member Functions
	Maybe (MaybeType tag)

Properties
MaybeType	Tag [get]
	Type discriminator.

Detailed Description

The Maybe type models an optional value. A value of type Maybe a either contains a value of type a (represented as Just a), or it is empty (represented as Nothing).

Provides static methods for manipulating CSharpx.Maybe.

Definition at line 32 of file Maybe.cs.

Constructor & Destructor Documentation

Maybe()

CSharpx.Maybe< T >.Maybe ( MaybeType  tag )

protected

Definition at line 34 of file Maybe.cs.

        {
            Tag = tag;
        }

Member Function Documentation

Bind< T1, T2 >()

static Maybe< T2 > CSharpx.Maybe< T >.Bind< T1, T2 > ( Maybe< T1 >  maybe, Func< T1, Maybe< T2 > >  func  )

static

Sequentially compose two actions, passing any value produced by the first as an argument to the second.

Definition at line 142 of file Maybe.cs.

        {
            T1 value1;
 
            return maybe.MatchJust(out value1) ? func(value1) : Nothing<T2>();
        }

FromEither< TLeft, TRight >()

static Maybe< TRight > CSharpx.Maybe< T >.FromEither< TLeft, TRight > ( Either< TLeft, TRight >  either )

static

Maps Either Right value to Maybe Just, otherwise Maybe Nothing.

Definition at line 185 of file Maybe.cs.

        {
            if (either.Tag == EitherType.Right) {
                return Maybe.Just(((Right<TLeft, TRight>)either).Value);
            }
            return Maybe.Nothing<TRight>();
        }

Just< T >()

static Just< T > CSharpx.Maybe< T >.Just< T > ( T  value )

static

Builds the case when CSharpx.Maybe contains a value.

Definition at line 122 of file Maybe.cs.

        {
            return new Just<T>(value);
        }

Map< T1, T2 >()

static Maybe< T2 > CSharpx.Maybe< T >.Map< T1, T2 > ( Maybe< T1 >  maybe, Func< T1, T2 >  func  )

static

Transforms an maybe value by using a specified mapping function.

Definition at line 156 of file Maybe.cs.

        {
            T1 value1;
 
            return maybe.MatchJust(out value1) ? Just(func(value1)) : Nothing<T2>();
        }

MatchJust()

bool CSharpx.Maybe< T >.MatchJust

(

out T

value

)

Matches a value returning true and value itself via output parameter.

Definition at line 49 of file Maybe.cs.

        {
            value = Tag == MaybeType.Just ? ((Just<T>)this).Value : default;
 
            return Tag == MaybeType.Just;
        }

MatchNothing()

bool CSharpx.Maybe< T >.MatchNothing

(

)

Matches an empty value returning true.

Definition at line 59 of file Maybe.cs.

        {
            return Tag == MaybeType.Nothing;
        }

Merge< T1, T2 >()

static Maybe< Tuple< T1, T2 > > CSharpx.Maybe< T >.Merge< T1, T2 > ( Maybe< T1 >  first, Maybe< T2 >  second  )

static

If both maybes contain a value, it merges them into a maybe with a tupled value.

Definition at line 168 of file Maybe.cs.

        {
            T1 value1;
            T2 value2;
 
            if (first.MatchJust(out value1) && second.MatchJust(out value2))
            {
                return Just(Tuple.Create(value1, value2));
            }
 
            return Nothing<Tuple<T1, T2>>();
        }

Nothing< T >()

static Maybe< T > CSharpx.Maybe< T >.Nothing< T > ( )

static

Builds the empty case of CSharpx.Maybe.

Definition at line 114 of file Maybe.cs.

        {
            return new Nothing<T>();
        }

Return< T >()

static Maybe< T > CSharpx.Maybe< T >.Return< T > ( T  value )

static

Inject a value into the monadic CSharpx.Maybe<T> type.

Definition at line 134 of file Maybe.cs.

        {
            return Equals(value, default(T)) ? Nothing<T>() : Just(value);
        }

Property Documentation

Tag

MaybeType CSharpx.Maybe< T >.Tag

get

Type discriminator.

Definition at line 42 of file Maybe.cs.

{ get; }

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The documentation for this class was generated from the following file:

• deps/commandlineparser/src/CommandLine/Infrastructure/CSharpx/Maybe.cs