java.lang.Object

com.jnape.palatable.lambda.adt.These<A,B>

Type Parameters:: A - the first possible type; B - the second possible type

All Implemented Interfaces:: CoProduct3<A, B, Tuple2<A,B>, These<A,B>>, Applicative<B, These<A,?>>, Bifunctor<A, B, These<?,?>>, BoundedBifunctor<A, B, Object, Object, These<?,?>>, Functor<B, These<A,?>>, Monad<B, These<A,?>>, MonadRec<B, These<A,?>>, Traversable<B, These<A,?>>

public abstract class These<A,B> extends Object implements CoProduct3<A, B, Tuple2<A,B>, These<A,B>>, MonadRec<B, These<A,?>>, Bifunctor<A, B, These<?,?>>, Traversable<B, These<A,?>>

The coproduct of a coproduct (CoProduct2<A, B>) and its product (Tuple2<A, B>), represented as a

CoProduct3<A, B, Tuple2<A,
B>>

.

Method Summary

Modifier and Type

Method

Description

static <A,B> These<A,B>

a(A a)

Static factory method for wrapping a value of type A in a These.

static <A,B> These<A,B>

b(B b)

Static factory method for wrapping a value of type B in a These.

final <C,D> These<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.

final <Z> These<Z,B>

biMapL(Fn1<? super A, ? extends Z> fn)

Covariantly map over the left parameter.

final <C> These<A,C>

biMapR(Fn1<? super B, ? extends C> fn)

Covariantly map over the right parameter.

static <A,B> These<A,B>

both(A a, B b)

Static factory method for wrapping a value of type A and a value of type B in a These.

final <C> These<A,C>

discardL(Applicative<C, These<A,?>> appB)

Sequence both this Applicative and appB, discarding this Applicative's result and returning appB.

final <C> These<A,B>

discardR(Applicative<C, These<A,?>> appB)

Sequence both this Applicative and appB, discarding appB's result and returning this Applicative.

final <C> These<A,C>

flatMap(Fn1<? super B, ? extends Monad<C, These<A,?>>> f)

Chain dependent computations that may continue or short-circuit based on previous results.

final <C> These<A,C>

fmap(Fn1<? super B, ? extends C> fn)

Covariantly transmute this functor's parameter using the given mapping function.

static <A,B> Maybe<These<A,B>>

fromMaybes(Maybe<A> maybeA, Maybe<B> maybeB)

Convenience method for converting a pair of Maybes into a Maybe of These.

<C> Lazy<These<A,C>>

lazyZip(Lazy<? extends Applicative<Fn1<? super B, ? extends C>, These<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.

final <C> These<A,C>

pure(C c)

Lift the value b into this applicative functor.

static <A> Pure<These<A,?>>

pureThese()

The canonical Pure instance for These.

<C> These<A,C>

trampolineM(Fn1<? super B, ? extends MonadRec<RecursiveResult<B,C>, These<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>, TravC extends Traversable<C, These<A,?>>, AppTrav extends Applicative<TravC,App>> AppTrav

traverse(Fn1<? super B, ? extends Applicative<C,App>> fn, Fn1<? super TravC, ? 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.

final <C> These<A,C>

zip(Applicative<Fn1<? super B, ? extends C>, These<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 Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface CoProduct3
converge, diverge, embed, match, project, projectA, projectB, projectC

Methods inherited from interface Functor
coerce

Method Details
- biMap
  
  public final <C,D> These<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, These<?,?>>
  
  Specified by:
  
  biMap in interface BoundedBifunctor<A, B, Object, Object, These<?,?>>
  
  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)
- flatMap
  
  public final <C> These<A,C> flatMap(Fn1<? super B, ? extends Monad<C, These<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
- trampolineM
  public <C> These<A,C> trampolineM(Fn1<? super B, ? extends MonadRec<RecursiveResult<B,C>, These<A,?>>> fn)
  
  Given some operation yielding a RecursiveResult inside this MonadRec, internally trampoline the operation until it yields a termination instruction.
  Stack-safety depends on implementations guaranteeing that the growth of the call stack is a constant factor independent of the number of invocations of the operation. For various examples of how this can be achieved in stereotypical circumstances, see the referenced types.
  
  Specified by:
  
  trampolineM in interface MonadRec<A,B>
  
  Type Parameters:
  
  C - the ultimate resulting carrier type
  
  Parameters:
  
  fn - the function to internally trampoline
  
  Returns:
  
  the trampolined MonadRec
  
  See Also:
  
  for a basic implementation
  
  for a coproduct implementation
  
  for an implementation leveraging an already stack-safe Monad#flatMap(Fn1)
  
  for a monad transformer implementation
- pure
  
  public final <C> These<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
- traverse
  
  public <C, App extends Applicative<?,App>, TravC extends Traversable<C, These<A,?>>, AppTrav extends Applicative<TravC,App>> AppTrav traverse(Fn1<? super B, ? extends Applicative<C,App>> fn, Fn1<? super TravC, ? 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
  
  TravC - 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
- biMapL
  
  public final <Z> These<Z,B> biMapL(Fn1<? super A, ? extends Z> fn)
  
  Covariantly map over the left parameter.
  
  Specified by:
  
  biMapL in interface Bifunctor<A, B, These<?,?>>
  
  Specified by:
  
  biMapL in interface BoundedBifunctor<A, B, Object, Object, These<?,?>>
  
  Type Parameters:
  
  Z - 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> These<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, These<?,?>>
  
  Specified by:
  
  biMapR in interface BoundedBifunctor<A, B, Object, Object, These<?,?>>
  
  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)
- fmap
  
  public final <C> These<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)
- zip
  
  public final <C> These<A,C> zip(Applicative<Fn1<? super B, ? extends C>, These<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<These<A,C>> lazyZip(Lazy<? extends Applicative<Fn1<? super B, ? extends C>, These<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 final <C> These<A,C> discardL(Applicative<C, These<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 final <C> These<A,B> discardR(Applicative<C, These<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
- a
  
  public static <A,B> These<A,B> a(A a)
  
  Static factory method for wrapping a value of type A in a These.
  
  Type Parameters:
  
  A - the first possible type
  
  B - the second possible type
  
  Parameters:
  
  a - the value
  
  Returns:
  
  the wrapped value as a These<A,B>
- b
  
  public static <A,B> These<A,B> b(B b)
  
  Static factory method for wrapping a value of type B in a These.
  
  Type Parameters:
  
  A - the first possible type
  
  B - the second possible type
  
  Parameters:
  
  b - the value
  
  Returns:
  
  the wrapped value as a These<A,B>
- both
  
  public static <A,B> These<A,B> both(A a, B b)
  
  Static factory method for wrapping a value of type A and a value of type B in a These.
  
  Type Parameters:
  
  A - the first possible type
  
  B - the second possible type
  
  Parameters:
  
  a - the first value
  
  b - the second value
  
  Returns:
  
  the wrapped values as a These<A,B>
- fromMaybes
  
  public static <A,B> Maybe<These<A,B>> fromMaybes(Maybe<A> maybeA, Maybe<B> maybeB)
  
  Convenience method for converting a pair of Maybes into a Maybe of These. If both Maybes are Maybe.just(A) then the result is a Maybe.just(A) both(A, B). If only one Maybe is Maybe.just(A) then it will be Maybe.just(A) a(A) or Maybe.just(A) b(B). If both Maybes are Maybe.nothing() then the result will be Maybe.nothing().
  
  Type Parameters:
  
  A - the first possible type
  
  B - the second possible type
  
  Parameters:
  
  maybeA - the first optional value
  
  maybeB - the second optional value
  
  Returns:
  
  the wrapped values as a Maybe<These<A,B>>
- pureThese
  
  public static <A> Pure<These<A,?>> pureThese()
  
  The canonical Pure instance for These.
  
  Type Parameters:
  
  A - the first possible type
  
  Returns:
  
  the Pure instance

Class These<A,B>

Method Summary

Methods inherited from class Object

Methods inherited from interface CoProduct3

Methods inherited from interface Functor

Method Details

biMap

flatMap

trampolineM

pure

traverse

biMapL

biMapR

fmap

zip

lazyZip

discardL

discardR

a

b

both

fromMaybes

pureThese