Class Choice2<A,​B>

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      private static class  Choice2._A<A,​B>  
      private static class  Choice2._B<A,​B>  
    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      private Choice2()  
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      static <A,​B>
      Choice2<A,​B>
      a​(A a)
      Static factory method for wrapping a value of type A in a Choice2.
      static <A,​B>
      Choice2<A,​B>
      b​(B b)
      Static factory method for wrapping a value of type B in a Choice2.
      <C,​D>
      Choice2<C,​D>
      biMap​(Fn1<? super A,​? extends C> lFn, Fn1<? super B,​? extends D> rFn)
      Dually map covariantly over both the left and right parameters.
      <C> Choice2<C,​B> biMapL​(Fn1<? super A,​? extends C> fn)
      Covariantly map over the left parameter.
      <C> Choice2<A,​C> biMapR​(Fn1<? super B,​? extends C> fn)
      Covariantly map over the right parameter.
      <C> Choice2<A,​C> discardL​(Applicative<C,​Choice2<A,​?>> appB)
      Sequence both this Applicative and appB, discarding this Applicative's result and returning appB.
      <C> Choice2<A,​B> discardR​(Applicative<C,​Choice2<A,​?>> appB)
      Sequence both this Applicative and appB, discarding appB's result and returning this Applicative.
      <C> Choice3<A,​B,​C> diverge()
      Diverge this coproduct by introducing another possible type that it could represent.
      <C> Choice2<A,​C> flatMap​(Fn1<? super B,​? extends Monad<C,​Choice2<A,​?>>> f)
      Chain dependent computations that may continue or short-circuit based on previous results.
      <C> Choice2<A,​C> fmap​(Fn1<? super B,​? extends C> fn)
      Covariantly transmute this functor's parameter using the given mapping function.
      Choice2<B,​A> invert()
      Swap the type parameters.
      <C> Lazy<Choice2<A,​C>> lazyZip​(Lazy<? extends Applicative<Fn1<? super B,​? extends C>,​Choice2<A,​?>>> lazyAppFn)
      Given a lazy instance of this applicative over a mapping function, "zip" the two instances together using whatever application semantics the current applicative supports.
      Tuple2<Maybe<A>,​Maybe<B>> project()
      Specialize this choice's projection to a Tuple2.
      <C> Choice2<A,​C> pure​(C c)
      Lift the value b into this applicative functor.
      static <A> Pure<Choice2<A,​?>> pureChoice()
      The canonical Pure instance for Choice2.
      <C> Choice2<A,​C> trampolineM​(Fn1<? super B,​? extends MonadRec<RecursiveResult<B,​C>,​Choice2<A,​?>>> fn)
      Given some operation yielding a RecursiveResult inside this MonadRec, internally trampoline the operation until it yields a termination instruction.
      <C,​App extends Applicative<?,​App>,​TravB extends Traversable<C,​Choice2<A,​?>>,​AppTrav extends Applicative<TravB,​App>>
      AppTrav
      traverse​(Fn1<? super B,​? extends Applicative<C,​App>> fn, Fn1<? super TravB,​? extends AppTrav> pure)
      Apply fn to each element of this traversable from left to right, and collapse the results into a single resulting applicative, potentially with the assistance of the applicative's pure function.
      <C> Choice2<A,​C> zip​(Applicative<Fn1<? super B,​? extends C>,​Choice2<A,​?>> appFn)
      Given another instance of this applicative over a mapping function, "zip" the two instances together using whatever application semantics the current applicative supports.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
      • Methods inherited from interface com.jnape.palatable.lambda.functor.Functor

        coerce
    • Constructor Detail

      • Choice2

        private Choice2()
    • Method Detail

      • diverge

        public final <C> Choice3<A,​B,​C> diverge()
        Diverge this coproduct by introducing another possible type that it could represent. As no morphisms can be provided mapping current types to the new type, this operation merely acts as a convenience method to allow the use of a more convergent coproduct with a more divergent one; that is, if a CoProduct3<String, Integer, Boolean> is expected, a CoProduct2<String, Integer> should suffice.

        Generally, we use inheritance to make this a non-issue; however, with coproducts of differing magnitudes, we cannot guarantee variance compatibility in one direction conveniently at construction time, and in the other direction, at all. A CoProduct2 could not be a CoProduct3 without specifying all type parameters that are possible for a CoProduct3 - more specifically, the third possible type - which is not necessarily known at construction time, or even useful if never used in the context of a CoProduct3. The inverse inheritance relationship - CoProduct3 < CoProduct2 - is inherently unsound, as a CoProduct3 cannot correctly implement CoProduct2.match(com.jnape.palatable.lambda.functions.Fn1<? super A, ? extends R>, com.jnape.palatable.lambda.functions.Fn1<? super B, ? extends R>), given that the third type C is always possible.

        For this reason, there is a diverge method supported between all CoProduct types of single magnitude difference.

        Specified by:
        diverge in interface CoProduct2<A,​B,​Choice2<A,​B>>
        Type Parameters:
        C - the additional possible type of this coproduct
        Returns:
        a CoProduct3<A, B, C>
      • fmap

        public final <C> Choice2<A,​C> fmap​(Fn1<? super B,​? extends C> fn)
        Covariantly transmute this functor's parameter using the given mapping function. Generally this method is specialized to return an instance of the class implementing Functor.
        Specified by:
        fmap in interface Applicative<A,​B>
        Specified by:
        fmap in interface Functor<A,​B>
        Specified by:
        fmap in interface Monad<A,​B>
        Specified by:
        fmap in interface MonadRec<A,​B>
        Specified by:
        fmap in interface Traversable<A,​B>
        Type Parameters:
        C - the new parameter type
        Parameters:
        fn - the mapping function
        Returns:
        a functor over B (the new parameter type)
      • biMapL

        public final <C> Choice2<C,​B> biMapL​(Fn1<? super A,​? extends C> fn)
        Covariantly map over the left parameter.
        Specified by:
        biMapL in interface Bifunctor<A,​B,​Choice2<?,​?>>
        Specified by:
        biMapL in interface BoundedBifunctor<A,​B,​java.lang.Object,​java.lang.Object,​Choice2<?,​?>>
        Type Parameters:
        C - the new left parameter type
        Parameters:
        fn - the mapping function
        Returns:
        a bifunctor over C (the new left parameter) and B (the same right parameter)
      • biMapR

        public final <C> Choice2<A,​C> biMapR​(Fn1<? super B,​? extends C> fn)
        Covariantly map over the right parameter. For all bifunctors that are also functors, it should hold that biMapR(f) == fmap(f).
        Specified by:
        biMapR in interface Bifunctor<A,​B,​Choice2<?,​?>>
        Specified by:
        biMapR in interface BoundedBifunctor<A,​B,​java.lang.Object,​java.lang.Object,​Choice2<?,​?>>
        Type Parameters:
        C - the new right parameter type
        Parameters:
        fn - the mapping function
        Returns:
        a bifunctor over A (the same left parameter) and C (the new right parameter)
      • biMap

        public final <C,​D> Choice2<C,​D> biMap​(Fn1<? super A,​? extends C> lFn,
                                                          Fn1<? super B,​? extends D> rFn)
        Dually map covariantly over both the left and right parameters. This is isomorphic to biMapL(lFn).biMapR(rFn).
        Specified by:
        biMap in interface Bifunctor<A,​B,​Choice2<?,​?>>
        Specified by:
        biMap in interface BoundedBifunctor<A,​B,​java.lang.Object,​java.lang.Object,​Choice2<?,​?>>
        Type Parameters:
        C - the new left parameter type
        D - the new right parameter type
        Parameters:
        lFn - the left parameter mapping function
        rFn - the right parameter mapping function
        Returns:
        a bifunctor over C (the new left parameter type) and D (the new right parameter type)
      • pure

        public <C> Choice2<A,​C> pure​(C c)
        Lift the value b into this applicative functor.
        Specified by:
        pure in interface Applicative<A,​B>
        Specified by:
        pure in interface Monad<A,​B>
        Specified by:
        pure in interface MonadRec<A,​B>
        Type Parameters:
        C - the type of the returned applicative's parameter
        Parameters:
        c - the value
        Returns:
        an instance of this applicative over b
      • zip

        public <C> Choice2<A,​C> zip​(Applicative<Fn1<? super B,​? extends C>,​Choice2<A,​?>> appFn)
        Given another instance of this applicative over a mapping function, "zip" the two instances together using whatever application semantics the current applicative supports.
        Specified by:
        zip in interface Applicative<A,​B>
        Specified by:
        zip in interface Monad<A,​B>
        Specified by:
        zip in interface MonadRec<A,​B>
        Type Parameters:
        C - the resulting applicative parameter type
        Parameters:
        appFn - the other applicative instance
        Returns:
        the mapped applicative
      • lazyZip

        public <C> Lazy<Choice2<A,​C>> lazyZip​(Lazy<? extends Applicative<Fn1<? super B,​? extends C>,​Choice2<A,​?>>> lazyAppFn)
        Given a lazy instance of this applicative over a mapping function, "zip" the two instances together using whatever application semantics the current applicative supports. This is useful for applicatives that support lazy evaluation and early termination.
        Specified by:
        lazyZip in interface Applicative<A,​B>
        Specified by:
        lazyZip in interface Monad<A,​B>
        Specified by:
        lazyZip in interface MonadRec<A,​B>
        Type Parameters:
        C - the resulting applicative parameter type
        Parameters:
        lazyAppFn - the lazy other applicative instance
        Returns:
        the mapped applicative
        See Also:
        Maybe, Either
      • discardL

        public <C> Choice2<A,​C> discardL​(Applicative<C,​Choice2<A,​?>> appB)
        Sequence both this Applicative and appB, discarding this Applicative's result and returning appB. This is generally useful for sequentially performing side-effects.
        Specified by:
        discardL in interface Applicative<A,​B>
        Specified by:
        discardL in interface Monad<A,​B>
        Specified by:
        discardL in interface MonadRec<A,​B>
        Type Parameters:
        C - the type of the returned Applicative's parameter
        Parameters:
        appB - the other Applicative
        Returns:
        appB
      • discardR

        public <C> Choice2<A,​B> discardR​(Applicative<C,​Choice2<A,​?>> appB)
        Sequence both this Applicative and appB, discarding appB's result and returning this Applicative. This is generally useful for sequentially performing side-effects.
        Specified by:
        discardR in interface Applicative<A,​B>
        Specified by:
        discardR in interface Monad<A,​B>
        Specified by:
        discardR in interface MonadRec<A,​B>
        Type Parameters:
        C - the type of appB's parameter
        Parameters:
        appB - the other Applicative
        Returns:
        this Applicative
      • flatMap

        public final <C> Choice2<A,​C> flatMap​(Fn1<? super B,​? extends Monad<C,​Choice2<A,​?>>> f)
        Chain dependent computations that may continue or short-circuit based on previous results.
        Specified by:
        flatMap in interface Monad<A,​B>
        Specified by:
        flatMap in interface MonadRec<A,​B>
        Type Parameters:
        C - the resulting monad parameter type
        Parameters:
        f - the dependent computation over A
        Returns:
        the new monad instance
      • traverse

        public <C,​App extends Applicative<?,​App>,​TravB extends Traversable<C,​Choice2<A,​?>>,​AppTrav extends Applicative<TravB,​App>> AppTrav traverse​(Fn1<? super B,​? extends Applicative<C,​App>> fn,
                                                                                                                                                                                              Fn1<? super TravB,​? extends AppTrav> pure)
        Apply fn to each element of this traversable from left to right, and collapse the results into a single resulting applicative, potentially with the assistance of the applicative's pure function.
        Specified by:
        traverse in interface Traversable<A,​B>
        Type Parameters:
        C - the resulting element type
        App - the result applicative type
        TravB - this Traversable instance over B
        AppTrav - the full inferred resulting type from the traversal
        Parameters:
        fn - the function to apply
        pure - the applicative pure function
        Returns:
        the traversed Traversable, wrapped inside an applicative
      • a

        public static <A,​B> Choice2<A,​B> a​(A a)
        Static factory method for wrapping a value of type A in a Choice2.
        Type Parameters:
        A - the first possible type
        B - the second possible type
        Parameters:
        a - the value
        Returns:
        the wrapped value as a Choice2<A, B>
      • b

        public static <A,​B> Choice2<A,​B> b​(B b)
        Static factory method for wrapping a value of type B in a Choice2.
        Type Parameters:
        A - the first possible type
        B - the second possible type
        Parameters:
        b - the value
        Returns:
        the wrapped value as a Choice2<A, B>
      • pureChoice

        public static <A> Pure<Choice2<A,​?>> pureChoice()
        The canonical Pure instance for Choice2.
        Type Parameters:
        A - the first possible type
        Returns:
        the Pure instance