Type Parameters:: E - the type of values in the case of invalid; T - the type of values in the case of valid

All Superinterfaces:: java.lang.Iterable<T>, java.io.Serializable, Value<T>

All Known Implementing Classes:: Validation.Invalid, Validation.Valid

public interface Validation<E,T>
extends Value<T>, java.io.Serializable

An implementation similar to Scalaz's Validation control.

The Validation type is an applicative functor, not a Monad. While a Monad short-circuits on the first error, an applicative functor accumulates all errors, making it particularly useful for validation scenarios where all errors should be reported.

 
 // Validation construction:

 // Valid
 Validation<String, Integer> valid = Validation.valid(5);

 // Invalid
 Validation<List<String>, Integer>invalid = Validation.invalid(List.of("error1", "error2"));

 // Validation combination:

 Validation<String, String> valid1 = Validation.valid("John");
 Validation<String, Integer> valid2 = Validation.valid(5);
 Validation<String, Option<String>> valid3 = Validation.valid(Option.of("123 Fake St."));
 Function3<String, Integer, Option<String>, Person> f = ...;

 Validation<List<String>, String> result =
     valid1.combine(valid2).ap((name, age) -> "Name: " + name + " Age: " + age);

 Validation<List<String>, Person> result2 =
     valid1.combine(valid2).combine(valid3).ap(f);

 // Another way to combine validations:
 Validation<List<String>, Person> result3 =
     Validation.combine(valid1, valid2, valid3).ap(f);

See Also:: Scalaz Validation source

Nested Class Summary

Nested Classes
Modifier and Type	Interface	Description
`static class`	`Validation.Builder<E,T1,T2>`	A builder that holds two Validation instances, used for combining validations and applying functions that take two arguments.
`static class`	`Validation.Builder3<E,T1,T2,T3>`	A builder that holds three Validation instances, used for combining validations and applying functions that take three arguments.
`static class`	`Validation.Builder4<E,T1,T2,T3,T4>`	A builder that holds four Validation instances, used for combining validations and applying functions that take four arguments.
`static class`	`Validation.Builder5<E,T1,T2,T3,T4,T5>`	A builder that holds five Validation instances, used for combining validations and applying functions that take five arguments.
`static class`	`Validation.Builder6<E,T1,T2,T3,T4,T5,T6>`	A builder that holds six Validation instances, used for combining validations and applying functions that take six arguments.
`static class`	`Validation.Builder7<E,T1,T2,T3,T4,T5,T6,T7>`	A builder that holds seven Validation instances, used for combining validations and applying functions that take seven arguments.
`static class`	`Validation.Builder8<E,T1,T2,T3,T4,T5,T6,T7,T8>`	A builder that holds eight Validation instances, used for combining validations and applying functions that take eight arguments.
`static class`	`Validation.Invalid<E,T>`	An invalid Validation
`static class`	`Validation.Valid<E,T>`	A valid Validation

Field Summary

Fields
Modifier and Type Field Description

static long serialVersionUID
The serial version UID for serialization.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`default <U> Validation<Seq<E>,U>`	`ap(@NonNull Validation<Seq<E>,? extends java.util.function.Function<? super T,? extends U>> validation)`	Applies a validation containing a function to this validation's value, combining errors if both are invalid.
`default <E2,T2> Validation<E2,T2>`	`bimap(@NonNull java.util.function.Function<? super E,? extends E2> errorMapper, @NonNull java.util.function.Function<? super T,? extends T2> valueMapper)`	Whereas map only performs a mapping on a valid Validation, and mapError performs a mapping on an invalid Validation, bimap allows you to provide mapping actions for both, and will give you the result based on what type of Validation this is.
`static <E,T1,T2> Validation.Builder<E,T1,T2>`	`combine(@NonNull Validation<E,T1> validation1, @NonNull Validation<E,T2> validation2)`	Combines two `Validation`s into a `Validation.Builder`.
`static <E,T1,T2,T3> Validation.Builder3<E,T1,T2,T3>`	`combine(@NonNull Validation<E,T1> validation1, @NonNull Validation<E,T2> validation2, @NonNull Validation<E,T3> validation3)`	Combines three `Validation`s into a `Validation.Builder3`.
`static <E,T1,T2,T3,T4> Validation.Builder4<E,T1,T2,T3,T4>`	`combine(@NonNull Validation<E,T1> validation1, @NonNull Validation<E,T2> validation2, @NonNull Validation<E,T3> validation3, @NonNull Validation<E,T4> validation4)`	Combines four `Validation`s into a `Validation.Builder4`.
`static <E,T1,T2,T3,T4,T5> Validation.Builder5<E,T1,T2,T3,T4,T5>`	`combine(@NonNull Validation<E,T1> validation1, @NonNull Validation<E,T2> validation2, @NonNull Validation<E,T3> validation3, @NonNull Validation<E,T4> validation4, @NonNull Validation<E,T5> validation5)`	Combines five `Validation`s into a `Validation.Builder5`.
`static <E,T1,T2,T3,T4,T5,T6> Validation.Builder6<E,T1,T2,T3,T4,T5,T6>`	`combine(@NonNull Validation<E,T1> validation1, @NonNull Validation<E,T2> validation2, @NonNull Validation<E,T3> validation3, @NonNull Validation<E,T4> validation4, @NonNull Validation<E,T5> validation5, @NonNull Validation<E,T6> validation6)`	Combines six `Validation`s into a `Validation.Builder6`.
`static <E,T1,T2,T3,T4,T5,T6,T7> Validation.Builder7<E,T1,T2,T3,T4,T5,T6,T7>`	`combine(@NonNull Validation<E,T1> validation1, @NonNull Validation<E,T2> validation2, @NonNull Validation<E,T3> validation3, @NonNull Validation<E,T4> validation4, @NonNull Validation<E,T5> validation5, @NonNull Validation<E,T6> validation6, @NonNull Validation<E,T7> validation7)`	Combines seven `Validation`s into a `Validation.Builder7`.
`static <E,T1,T2,T3,T4,T5,T6,T7,T8> Validation.Builder8<E,T1,T2,T3,T4,T5,T6,T7,T8>`	`combine(@NonNull Validation<E,T1> validation1, @NonNull Validation<E,T2> validation2, @NonNull Validation<E,T3> validation3, @NonNull Validation<E,T4> validation4, @NonNull Validation<E,T5> validation5, @NonNull Validation<E,T6> validation6, @NonNull Validation<E,T7> validation7, @NonNull Validation<E,T8> validation8)`	Combines eight `Validation`s into a `Validation.Builder8`.
`default <U> Validation.Builder<E,T,U>`	`combine(Validation<E,U> validation)`	Combines two `Validation`s to form a `Validation.Builder`, which can then be used to perform further combines, or apply a function to it in order to transform the `Validation.Builder` into a `Validation`.
`static <E,T> Validation<E,T>`	`cond(boolean test, @NonNull java.util.function.Supplier<? extends T> valid, @NonNull java.util.function.Supplier<? extends E> error)`	Decides which `Validation<E, T>` to return, depending on the test value - if it's true, the result will be a `Validation.Valid`, if it's false - the result will be a `Validation.Invalid`
`static <E,T> Validation<E,T>`	`cond(boolean test, @NonNull T valid, @NonNull E error)`	Decides which `Validation<E, T>` to return, depending on the test value - if it's true, the result will be a `Validation.Valid`, if it's false - the result will be a `Validation.Invalid`
`boolean`	`equals(java.lang.Object o)`	Clarifies that values have a proper equals() method implemented.
`default Option<Validation<E,T>>`	`filter(@NonNull java.util.function.Predicate<? super T> predicate)`	Filters this `Validation` by testing a predicate on the value.
`default <U> Validation<E,U>`	`flatMap(@NonNull java.util.function.Function<? super T,? extends Validation<E,? extends U>> mapper)`	FlatMaps the value of this Validation if it is valid, otherwise returns this Invalid.
`default <U> U`	`fold(@NonNull java.util.function.Function<? super E,? extends U> ifInvalid, @NonNull java.util.function.Function<? super T,? extends U> ifValid)`	Transforms this `Validation` to a value of type `U`.
`default void`	`forEach(@NonNull java.util.function.Consumer<? super T> action)`	Performs the given action for the value contained in `Valid`, or does nothing if this is an `Invalid`.
`static <E,T> Validation<E,T>`	`fromEither(@NonNull Either<E,T> either)`	Creates a `Validation` of an `Either`.
`static <T> Validation<java.lang.Throwable,T>`	`fromTry(@NonNull Try<? extends T> t)`	Creates a `Validation` of an `Try`.
`T`	`get()`	Gets the value of this `Validation` if is a `Valid` or throws if this is an `Invalid`.
`E`	`getError()`	Gets the error of this Validation if it is an `Invalid` or throws if this is a `Valid`.
`default T`	`getOrElseGet(@NonNull java.util.function.Function<? super E,? extends T> other)`	Gets the value if it is a Valid or an value calculated from the error.
`int`	`hashCode()`	Clarifies that values have a proper hashCode() method implemented.
`static <E,T> Validation<E,T>`	`invalid(E error)`	Creates an `Validation.Invalid` that contains the given `error`.
`default boolean`	`isAsync()`	A `Validation`'s value is computed synchronously.
`default boolean`	`isEmpty()`	Checks, this `Value` is empty, i.e.
`boolean`	`isInvalid()`	Check whether this is of type `Invalid`
`default boolean`	`isLazy()`	A `Validation`'s value is computed eagerly.
`default boolean`	`isSingleValued()`	States whether this is a single-valued type.
`boolean`	`isValid()`	Check whether this is of type `Valid`
`default @NonNull Iterator<T>`	`iterator()`	Returns a rich `io.vavr.collection.Iterator`.
`default <U> Validation<E,U>`	`map(@NonNull java.util.function.Function<? super T,? extends U> f)`	Maps the underlying value to a different component type.
`default <U> Validation<U,T>`	`mapError(@NonNull java.util.function.Function<? super E,? extends U> f)`	Applies a function f to the error of this Validation if this is an Invalid.
`static <E,T> Validation<E,T>`	`narrow(Validation<? extends E,? extends T> validation)`	Narrows a widened `Validation<? extends E, ? extends T>` to `Validation<E, T>` by performing a type-safe cast.
`default Validation<E,T>`	`orElse(@NonNull Validation<? extends E,? extends T> other)`	Returns this `Validation` if it is valid, otherwise return the alternative.
`default Validation<E,T>`	`orElse(@NonNull java.util.function.Supplier<Validation<? extends E,? extends T>> supplier)`	Returns this `Validation` if it is valid, otherwise return the result of evaluating supplier.
`default Validation<E,T>`	`peek(@NonNull java.util.function.Consumer<? super T> action)`	Performs the given `action` on the first element if this is an eager implementation.
`static <E,T> Validation<Seq<E>,Seq<T>>`	`sequence(@NonNull java.lang.Iterable<? extends Validation<? extends Seq<? extends E>,? extends T>> values)`	Reduces many `Validation` instances into a single `Validation` by transforming an `Iterable<Validation<? extends T>>` into a `Validation<Seq<T>>`.
`default Validation<T,E>`	`swap()`	Flip the valid/invalid values for this Validation.
`default Either<E,T>`	`toEither()`	Converts this Validation to an `Either`.
`java.lang.String`	`toString()`	Clarifies that values have a proper toString() method implemented.
`static <E,T,U> Validation<Seq<E>,Seq<U>>`	`traverse(@NonNull java.lang.Iterable<? extends T> values, @NonNull java.util.function.Function<? super T,? extends Validation<? extends Seq<? extends E>,? extends U>> mapper)`	Maps the values of an iterable to a sequence of mapped values into a single `Validation` by transforming an `Iterable<? extends T>` into a `Validation<Seq<U>>`.
`static <E,T> Validation<E,T>`	`valid(T value)`	Creates a `Validation.Valid` that contains the given `value`.

Methods inherited from interface io.vavr.Value
collect, collect, contains, corresponds, eq, exists, forAll, getOrElse, getOrElse, getOrElseThrow, getOrElseTry, getOrNull, mapTo, mapToVoid, out, out, spliterator, stderr, stdout, stringPrefix, toArray, toCharSeq, toCompletableFuture, toEither, toEither, toInvalid, toInvalid, toJavaArray, toJavaArray, toJavaArray, toJavaCollection, toJavaList, toJavaList, toJavaMap, toJavaMap, toJavaMap, toJavaOptional, toJavaParallelStream, toJavaSet, toJavaSet, toJavaStream, toLeft, toLeft, toLinkedMap, toLinkedMap, toLinkedSet, toList, toMap, toMap, toOption, toPriorityQueue, toPriorityQueue, toQueue, toRight, toRight, toSet, toSortedMap, toSortedMap, toSortedMap, toSortedMap, toSortedSet, toSortedSet, toStream, toTree, toTree, toTry, toTry, toValid, toValid, toValidation, toValidation, toVector

- Field Detail
 - serialVersionUID
```
static final long serialVersionUID
```
 The serial version UID for serialization.
 
 See Also:
 
 Constant Field Values
- Method Detail
 - valid
```
static <E,T> Validation<E,T> valid(T value)
```
 Creates a Validation.Valid that contains the given value.
 
 Type Parameters:
 
 E - type of the error
 
 T - type of the given value
 
 Parameters:
 
 value - A value
 
 Returns:
 
 Valid(value)
 - invalid
```
static <E,T> Validation<E,T> invalid(E error)
```
 Creates an Validation.Invalid that contains the given error.
 
 Type Parameters:
 
 E - type of the given error
 
 T - type of the value
 
 Parameters:
 
 error - An error
 
 Returns:
 
 Invalid(error)
 
 Throws:
 
 java.lang.NullPointerException - if error is null
 - fromEither
```
static <E,T> Validation<E,T> fromEither(@NonNull Either<E,T> either)
```
 Creates a Validation of an Either.
 
 Type Parameters:
 
 E - error type
 
 T - value type
 
 Parameters:
 
 either - An Either
 
 Returns:
 
 A Valid(either.get()) if either is a Right, otherwise Invalid(either.getLeft()).
 
 Throws:
 
 java.lang.NullPointerException - if either is null
 - fromTry
```
static <T> Validation<java.lang.Throwable,T> fromTry(@NonNull Try<? extends T> t)
```
 Creates a Validation of an Try.
 
 Type Parameters:
 
 T - type of the valid value
 
 Parameters:
 
 t - A Try
 
 Returns:
 
 A Valid(t.get()) if t is a Success, otherwise Invalid(t.getCause()).
 
 Throws:
 
 java.lang.NullPointerException - if t is null
 - sequence
```
static <E,T> Validation<Seq<E>,Seq<T>> sequence(@NonNull java.lang.Iterable<? extends Validation<? extends Seq<? extends E>,? extends T>> values)
```
 Reduces many Validation instances into a single Validation by transforming an Iterable<Validation<? extends T>> into a Validation<Seq<T>>.
 
 Type Parameters:
 
 E - value type in the case of invalid
 
 T - value type in the case of valid
 
 Parameters:
 
 values - An iterable of Validation instances.
 
 Returns:
 
 A valid Validation of a sequence of values if all Validation instances are valid or an invalid Validation containing an accumulated List of errors.
 
 Throws:
 
 java.lang.NullPointerException - if values is null
 - traverse
```
static <E,T,U> Validation<Seq<E>,Seq> traverse(@NonNull java.lang.Iterable<? extends T> values,
 @NonNull java.util.function.Function<? super T,? extends Validation<? extends Seq<? extends E>,? extends U>> mapper)
```
 Maps the values of an iterable to a sequence of mapped values into a single Validation by transforming an Iterable<? extends T> into a Validation<Seq>.
 
 Type Parameters:
 
 T - The type of the given values.
 
 E - The mapped error value type.
 
 U - The mapped valid value type.
 
 Parameters:
 
 values - An Iterable of values.
 
 mapper - A mapper of values to Validations
 
 Returns:
 
 A Validation of a Seq of results.
 
 Throws:
 
 java.lang.NullPointerException - if values or f is null.
 - narrow
```
static <E,T> Validation<E,T> narrow(Validation<? extends E,? extends T> validation)
```
 Narrows a widened Validation<? extends E, ? extends T> to Validation<E, T> by performing a type-safe cast. This is eligible because immutable/read-only collections are covariant.
 
 Type Parameters:
 
 E - type of error
 
 T - type of valid value
 
 Parameters:
 
 validation - A Validation.
 
 Returns:
 
 the given validation instance as narrowed type Validation<E, T>.
 - cond
```
static <E,T> Validation<E,T> cond(boolean test,
 @NonNull java.util.function.Supplier<? extends T> valid,
 @NonNull java.util.function.Supplier<? extends E> error)
```
 Decides which Validation<E, T> to return, depending on the test value - if it's true, the result will be a Validation.Valid, if it's false - the result will be a Validation.Invalid
 
 Type Parameters:
 
 E - Type of error
 
 T - Type of valid value
 
 Parameters:
 
 test - A boolean value to evaluate
 
 valid - A Supplier<? extends T> supplier of valid value, called if test is true
 
 error - A Supplier<? extends E> supplier of error, called if test is false
 
 Returns:
 
 Validation<E, T> with valid value or error, depending on the test condition evaluation
 
 Throws:
 
 java.lang.NullPointerException - if any of the arguments is null
 - cond
```
static <E,T> Validation<E,T> cond(boolean test,
 @NonNull T valid,
 @NonNull E error)
```
 Decides which Validation<E, T> to return, depending on the test value - if it's true, the result will be a Validation.Valid, if it's false - the result will be a Validation.Invalid
 
 Type Parameters:
 
 E - Type of error
 
 T - Type of valid value
 
 Parameters:
 
 test - A boolean value to evaluate
 
 valid - A T valid value, called if test is true
 
 error - An E error value, called if test is false
 
 Returns:
 
 Validation<E, T> with valid value or error, depending on the test condition evaluation
 
 Throws:
 
 java.lang.NullPointerException - if any of the arguments is null
 - combine
```
static <E,T1,T2> Validation.Builder<E,T1,T2> combine(@NonNull Validation<E,T1> validation1,
 @NonNull Validation<E,T2> validation2)
```
 Combines two Validations into a Validation.Builder.
 
 Type Parameters:
 
 E - type of error
 
 T1 - type of first valid value
 
 T2 - type of second valid value
 
 Parameters:
 
 validation1 - first validation
 
 validation2 - second validation
 
 Returns:
 
 an instance of Builder<E,T1,T2>
 
 Throws:
 
 java.lang.NullPointerException - if validation1 or validation2 is null
 - combine
```
static <E,T1,T2,T3> Validation.Builder3<E,T1,T2,T3> combine(@NonNull Validation<E,T1> validation1,
 @NonNull Validation<E,T2> validation2,
 @NonNull Validation<E,T3> validation3)
```
 Combines three Validations into a Validation.Builder3.
 
 Type Parameters:
 
 E - type of error
 
 T1 - type of first valid value
 
 T2 - type of second valid value
 
 T3 - type of third valid value
 
 Parameters:
 
 validation1 - first validation
 
 validation2 - second validation
 
 validation3 - third validation
 
 Returns:
 
 an instance of Builder3<E,T1,T2,T3>
 
 Throws:
 
 java.lang.NullPointerException - if validation1, validation2 or validation3 is null
 - combine
```
static <E,T1,T2,T3,T4> Validation.Builder4<E,T1,T2,T3,T4> combine(@NonNull Validation<E,T1> validation1,
 @NonNull Validation<E,T2> validation2,
 @NonNull Validation<E,T3> validation3,
 @NonNull Validation<E,T4> validation4)
```
 Combines four Validations into a Validation.Builder4.
 
 Type Parameters:
 
 E - type of error
 
 T1 - type of first valid value
 
 T2 - type of second valid value
 
 T3 - type of third valid value
 
 T4 - type of fourth valid value
 
 Parameters:
 
 validation1 - first validation
 
 validation2 - second validation
 
 validation3 - third validation
 
 validation4 - fourth validation
 
 Returns:
 
 an instance of Builder3<E,T1,T2,T3,T4>
 
 Throws:
 
 java.lang.NullPointerException - if validation1, validation2, validation3 or validation4 is null
 - combine
```
static <E,T1,T2,T3,T4,T5> Validation.Builder5<E,T1,T2,T3,T4,T5> combine(@NonNull Validation<E,T1> validation1,
 @NonNull Validation<E,T2> validation2,
 @NonNull Validation<E,T3> validation3,
 @NonNull Validation<E,T4> validation4,
 @NonNull Validation<E,T5> validation5)
```
 Combines five Validations into a Validation.Builder5.
 
 Type Parameters:
 
 E - type of error
 
 T1 - type of first valid value
 
 T2 - type of second valid value
 
 T3 - type of third valid value
 
 T4 - type of fourth valid value
 
 T5 - type of fifth valid value
 
 Parameters:
 
 validation1 - first validation
 
 validation2 - second validation
 
 validation3 - third validation
 
 validation4 - fourth validation
 
 validation5 - fifth validation
 
 Returns:
 
 an instance of Builder3<E,T1,T2,T3,T4,T5>
 
 Throws:
 
 java.lang.NullPointerException - if validation1, validation2, validation3, validation4 or validation5 is null
 - combine
```
static <E,T1,T2,T3,T4,T5,T6> Validation.Builder6<E,T1,T2,T3,T4,T5,T6> combine(@NonNull Validation<E,T1> validation1,
 @NonNull Validation<E,T2> validation2,
 @NonNull Validation<E,T3> validation3,
 @NonNull Validation<E,T4> validation4,
 @NonNull Validation<E,T5> validation5,
 @NonNull Validation<E,T6> validation6)
```
 Combines six Validations into a Validation.Builder6.
 
 Type Parameters:
 
 E - type of error
 
 T1 - type of first valid value
 
 T2 - type of second valid value
 
 T3 - type of third valid value
 
 T4 - type of fourth valid value
 
 T5 - type of fifth valid value
 
 T6 - type of sixth valid value
 
 Parameters:
 
 validation1 - first validation
 
 validation2 - second validation
 
 validation3 - third validation
 
 validation4 - fourth validation
 
 validation5 - fifth validation
 
 validation6 - sixth validation
 
 Returns:
 
 an instance of Builder3<E,T1,T2,T3,T4,T5,T6>
 
 Throws:
 
 java.lang.NullPointerException - if validation1, validation2, validation3, validation4, validation5 or validation6 is null
 - combine
```
static <E,T1,T2,T3,T4,T5,T6,T7> Validation.Builder7<E,T1,T2,T3,T4,T5,T6,T7> combine(@NonNull Validation<E,T1> validation1,
 @NonNull Validation<E,T2> validation2,
 @NonNull Validation<E,T3> validation3,
 @NonNull Validation<E,T4> validation4,
 @NonNull Validation<E,T5> validation5,
 @NonNull Validation<E,T6> validation6,
 @NonNull Validation<E,T7> validation7)
```
 Combines seven Validations into a Validation.Builder7.
 
 Type Parameters:
 
 E - type of error
 
 T1 - type of first valid value
 
 T2 - type of second valid value
 
 T3 - type of third valid value
 
 T4 - type of fourth valid value
 
 T5 - type of fifth valid value
 
 T6 - type of sixth valid value
 
 T7 - type of seventh valid value
 
 Parameters:
 
 validation1 - first validation
 
 validation2 - second validation
 
 validation3 - third validation
 
 validation4 - fourth validation
 
 validation5 - fifth validation
 
 validation6 - sixth validation
 
 validation7 - seventh validation
 
 Returns:
 
 an instance of Builder3<E,T1,T2,T3,T4,T5,T6,T7>
 
 Throws:
 
 java.lang.NullPointerException - if validation1, validation2, validation3, validation4, validation5, validation6 or validation7 is null
 - combine
```
static <E,T1,T2,T3,T4,T5,T6,T7,T8> Validation.Builder8<E,T1,T2,T3,T4,T5,T6,T7,T8> combine(@NonNull Validation<E,T1> validation1,
 @NonNull Validation<E,T2> validation2,
 @NonNull Validation<E,T3> validation3,
 @NonNull Validation<E,T4> validation4,
 @NonNull Validation<E,T5> validation5,
 @NonNull Validation<E,T6> validation6,
 @NonNull Validation<E,T7> validation7,
 @NonNull Validation<E,T8> validation8)
```
 Combines eight Validations into a Validation.Builder8.
 
 Type Parameters:
 
 E - type of error
 
 T1 - type of first valid value
 
 T2 - type of second valid value
 
 T3 - type of third valid value
 
 T4 - type of fourth valid value
 
 T5 - type of fifth valid value
 
 T6 - type of sixth valid value
 
 T7 - type of seventh valid value
 
 T8 - type of eighth valid value
 
 Parameters:
 
 validation1 - first validation
 
 validation2 - second validation
 
 validation3 - third validation
 
 validation4 - fourth validation
 
 validation5 - fifth validation
 
 validation6 - sixth validation
 
 validation7 - seventh validation
 
 validation8 - eighth validation
 
 Returns:
 
 an instance of Builder3<E,T1,T2,T3,T4,T5,T6,T7,T8>
 
 Throws:
 
 java.lang.NullPointerException - if validation1, validation2, validation3, validation4, validation5, validation6, validation7 or validation8 is null
 - isValid
```
boolean isValid()
```
 Check whether this is of type Valid
 
 Returns:
 
 true if is a Valid, false if is an Invalid
 - isInvalid
```
boolean isInvalid()
```
 Check whether this is of type Invalid
 
 Returns:
 
 true if is an Invalid, false if is a Valid
 - orElse
```
default Validation<E,T> orElse(@NonNull Validation<? extends E,? extends T> other)
```
 Returns this Validation if it is valid, otherwise return the alternative.
 
 Parameters:
 
 other - An alternative Validation
 
 Returns:
 
 this Validation if it is valid, otherwise return the alternative.
 - orElse
```
default Validation<E,T> orElse(@NonNull java.util.function.Supplier<Validation<? extends E,? extends T>> supplier)
```
 Returns this Validation if it is valid, otherwise return the result of evaluating supplier.
 
 Parameters:
 
 supplier - An alternative Validation supplier
 
 Returns:
 
 this Validation if it is valid, otherwise return the result of evaluating supplier.
 - isEmpty
```
default boolean isEmpty()
```
 Description copied from interface: Value
 
 Checks, this Value is empty, i.e. if the underlying value is absent.
 
 Specified by:
 
 isEmpty in interface Value<E>
 
 Returns:
 
 false, if no underlying value is present, true otherwise.
 - get
```
T get()
```
 Gets the value of this Validation if is a Valid or throws if this is an Invalid.
 
 Specified by:
 
 get in interface Value<E>
 
 Returns:
 
 The value of this Validation
 
 Throws:
 
 java.util.NoSuchElementException - if this is an Invalid
 - getOrElseGet
```
default T getOrElseGet(@NonNull java.util.function.Function<? super E,? extends T> other)
```
 Gets the value if it is a Valid or an value calculated from the error.
 
 Parameters:
 
 other - a function which converts an error to an alternative value
 
 Returns:
 
 the value, if the underlying Validation is a Valid, or else the alternative value provided by other by applying the error.
 - getError
```
E getError()
```
 Gets the error of this Validation if it is an Invalid or throws if this is a Valid.
 
 Returns:
 
 The error, if present
 
 Throws:
 
 java.lang.RuntimeException - if this is a Valid
 - toEither
```
default Either<E,T> toEither()
```
 Converts this Validation to an Either.
 
 Returns:
 
 Either.right(get()) if this is valid, otherwise Either.left(getError()).
 - equals
```
boolean equals(java.lang.Object o)
```
 Description copied from interface: Value
 
 Clarifies that values have a proper equals() method implemented.
 See Object.equals(Object).
 
 Specified by:
 
 equals in interface Value<E>
 
 Overrides:
 
 equals in class java.lang.Object
 
 Parameters:
 
 o - An object
 
 Returns:
 
 true, if this equals o, false otherwise
 - hashCode
```
int hashCode()
```
 Description copied from interface: Value
 
 Clarifies that values have a proper hashCode() method implemented.
 See Object.hashCode().
 
 Specified by:
 
 hashCode in interface Value<E>
 
 Overrides:
 
 hashCode in class java.lang.Object
 
 Returns:
 
 The hashcode of this object
 - toString
```
java.lang.String toString()
```
 Description copied from interface: Value
 
 Clarifies that values have a proper toString() method implemented.
 See Object.toString().
 
 Specified by:
 
 toString in interface Value<E>
 
 Overrides:
 
 toString in class java.lang.Object
 
 Returns:
 
 A String representation of this object
 - forEach
```
default void forEach(@NonNull java.util.function.Consumer<? super T> action)
```
 Performs the given action for the value contained in Valid, or does nothing if this is an Invalid.
 
 Specified by:
 
 forEach in interface java.lang.Iterable<E>
 
 Specified by:
 
 forEach in interface Value<E>
 
 Parameters:
 
 action - the action to be performed on the contained value
 
 Throws:
 
 java.lang.NullPointerException - if action is null
 - fold
```
default  U fold(@NonNull java.util.function.Function<? super E,? extends U> ifInvalid,
 @NonNull java.util.function.Function<? super T,? extends U> ifValid)
```
 Transforms this Validation to a value of type U.
 Example:
 Validation<List<String>, String> valid = ...; int i = valid.fold(List::length, String::length);
 Type Parameters:
 
 U - the fold result type
 
 Parameters:
 
 ifInvalid - an error mapper
 
 ifValid - an mapper for a valid value
 
 Returns:
 
 ifValid.apply(get()) if this is valid, otherwise ifInvalid.apply(getError()).
 
 Throws:
 
 java.lang.NullPointerException - if one of the given mappers ifInvalid or ifValid is null
 - swap
```
default Validation<T,E> swap()
```
 Flip the valid/invalid values for this Validation. If this is a Valid<E,T>, returns Invalid<T,E>. Or if this is an Invalid<E,T>, return a Valid<T,E>.
 
 Returns:
 
 a flipped instance of Validation
 - map
```
default  Validation<E,U> map(@NonNull java.util.function.Function<? super T,? extends U> f)
```
 Description copied from interface: Value
 
 Maps the underlying value to a different component type.
 
 Specified by:
 
 map in interface Value<E>
 
 Type Parameters:
 
 U - The new component type
 
 Parameters:
 
 f - A mapper
 
 Returns:
 
 A new value
 - bimap
```
default <E2,T2> Validation<E2,T2> bimap(@NonNull java.util.function.Function<? super E,? extends E2> errorMapper,
 @NonNull java.util.function.Function<? super T,? extends T2> valueMapper)
```
 Whereas map only performs a mapping on a valid Validation, and mapError performs a mapping on an invalid Validation, bimap allows you to provide mapping actions for both, and will give you the result based on what type of Validation this is. Without this, you would have to do something like: validation.map(...).mapError(...);
 
 Type Parameters:
 
 E2 - type of the mapping result if this is an invalid
 
 T2 - type of the mapping result if this is a valid
 
 Parameters:
 
 errorMapper - the invalid mapping operation
 
 valueMapper - the valid mapping operation
 
 Returns:
 
 an instance of Validation<U,R>
 
 Throws:
 
 java.lang.NullPointerException - if invalidMapper or validMapper is null
 - mapError
```
default  Validation<U,T> mapError(@NonNull java.util.function.Function<? super E,? extends U> f)
```
 Applies a function f to the error of this Validation if this is an Invalid. Otherwise does nothing if this is a Valid.
 
 Type Parameters:
 
 U - type of the error resulting from the mapping
 
 Parameters:
 
 f - a function that maps the error in this Invalid
 
 Returns:
 
 an instance of Validation<U,T>
 
 Throws:
 
 java.lang.NullPointerException - if mapping operation f is null
 - ap
```
default  Validation<Seq<E>,U> ap(@NonNull Validation<Seq<E>,? extends java.util.function.Function<? super T,? extends U>> validation)
```
 Applies a validation containing a function to this validation's value, combining errors if both are invalid. This is the applicative functor's ap operation for Validation.
 
 Type Parameters:
 
 U - type of the result of applying the function
 
 Parameters:
 
 validation - the validation containing the function to apply
 
 Returns:
 
 a valid Validation with the result if both are valid, otherwise an invalid Validation with accumulated errors
 
 Throws:
 
 java.lang.NullPointerException - if validation is null
 - combine
```
default  Validation.Builder<E,T,U> combine(Validation<E,U> validation)
```
 Combines two Validations to form a Validation.Builder, which can then be used to perform further combines, or apply a function to it in order to transform the Validation.Builder into a Validation.
 
 Type Parameters:
 
 U - type of the value contained in validation
 
 Parameters:
 
 validation - the validation object to combine this with
 
 Returns:
 
 an instance of Builder
 - filter
```
default Option<Validation<E,T>> filter(@NonNull java.util.function.Predicate<? super T> predicate)
```
 Filters this Validation by testing a predicate on the value. If this is an Invalid or if the predicate matches, returns Some of this Validation, otherwise returns None.
 
 Parameters:
 
 predicate - A predicate to test the value
 
 Returns:
 
 Some(this) if this is an Invalid or the predicate matches, otherwise None
 
 Throws:
 
 java.lang.NullPointerException - if predicate is null
 - flatMap
```
default  Validation<E,U> flatMap(@NonNull java.util.function.Function<? super T,? extends Validation<E,? extends U>> mapper)
```
 FlatMaps the value of this Validation if it is valid, otherwise returns this Invalid.
 
 Type Parameters:
 
 U - type of the returned Validation value
 
 Parameters:
 
 mapper - the mapper function to apply to the value
 
 Returns:
 
 a new Validation
 
 Throws:
 
 java.lang.NullPointerException - if mapper is null
 - peek
```
default Validation<E,T> peek(@NonNull java.util.function.Consumer<? super T> action)
```
 Description copied from interface: Value
 
 Performs the given action on the first element if this is an eager implementation. Performs the given action on all elements (the first immediately, successive deferred), if this is a lazy implementation.
 
 Specified by:
 
 peek in interface Value<E>
 
 Parameters:
 
 action - The action that will be performed on the element(s).
 
 Returns:
 
 this instance
 - isAsync
```
default boolean isAsync()
```
 A Validation's value is computed synchronously.
 
 Specified by:
 
 isAsync in interface Value<E>
 
 Returns:
 
 false
 - isLazy
```
default boolean isLazy()
```
 A Validation's value is computed eagerly.
 
 Specified by:
 
 isLazy in interface Value<E>
 
 Returns:
 
 false
 - isSingleValued
```
default boolean isSingleValued()
```
 Description copied from interface: Value
 
 States whether this is a single-valued type.
 
 Specified by:
 
 isSingleValued in interface Value<E>
 
 Returns:
 
 true if this is single-valued, false otherwise.
 - iterator
```
default @NonNull Iterator<T> iterator()
```
 Description copied from interface: Value
 
 Returns a rich io.vavr.collection.Iterator.
 
 Specified by:
 
 iterator in interface java.lang.Iterable<E>
 
 Specified by:
 
 iterator in interface Value<E>
 
 Returns:
 
 A new Iterator

Interface Validation<E,​T>

Nested Class Summary

Field Summary

Method Summary

Methods inherited from interface io.vavr.Value

Field Detail

serialVersionUID

Method Detail

valid

invalid

fromEither

fromTry

sequence

traverse

narrow

cond

cond

combine

combine

combine

combine

combine

combine

combine

isValid

isInvalid

orElse

orElse

isEmpty

get

getOrElseGet

getError

toEither

equals

hashCode

toString

forEach

fold

swap

map

bimap

mapError

ap

combine

filter

flatMap

peek

isAsync

isLazy

isSingleValued

iterator

Interface Validation<E,T>