Package io.vavr
Interface Function4<T1,T2,T3,T4,R>
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- Type Parameters:
T1
- argument 1 of the functionT2
- argument 2 of the functionT3
- argument 3 of the functionT4
- argument 4 of the functionR
- return type of the function
- All Superinterfaces:
java.io.Serializable
- Functional Interface:
- This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
@FunctionalInterface public interface Function4<T1,T2,T3,T4,R> extends java.io.Serializable
Represents a function with 4 arguments.
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Field Summary
Fields Modifier and Type Field Description static long
serialVersionUID
The serial version uid.
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Method Summary
Modifier and Type Method Description default <V> Function4<T1,T2,T3,T4,V>
andThen(java.util.function.Function<? super R,? extends V> after)
Returns a composed function that first applies this Function4 to the given argument and then applies Functionafter
to the result.default Function3<T2,T3,T4,R>
apply(T1 t1)
Applies this function partially to one argument.default Function2<T3,T4,R>
apply(T1 t1, T2 t2)
Applies this function partially to two arguments.default Function1<T4,R>
apply(T1 t1, T2 t2, T3 t3)
Applies this function partially to three arguments.R
apply(T1 t1, T2 t2, T3 t3, T4 t4)
Applies this function to 4 arguments and returns the result.default int
arity()
Returns the number of function arguments.static <T1,T2,T3,T4,R>
Function4<T1,T2,T3,T4,R>constant(R value)
Returns a function that always returns the constant value that you give in parameter.default Function1<T1,Function1<T2,Function1<T3,Function1<T4,R>>>>
curried()
Returns a curried version of this function.default boolean
isMemoized()
Checks if this function is memoizing (= caching) computed values.static <T1,T2,T3,T4,R>
Function4<T1,T2,T3,T4,Option<R>>lift(Function4<? super T1,? super T2,? super T3,? super T4,? extends R> partialFunction)
Lifts the givenpartialFunction
into a total function that returns anOption
result.static <T1,T2,T3,T4,R>
Function4<T1,T2,T3,T4,Try<R>>liftTry(Function4<? super T1,? super T2,? super T3,? super T4,? extends R> partialFunction)
Lifts the givenpartialFunction
into a total function that returns anTry
result.default Function4<T1,T2,T3,T4,R>
memoized()
Returns a memoizing version of this function, which computes the return value for given arguments only one time.static <T1,T2,T3,T4,R>
Function4<T1,T2,T3,T4,R>narrow(Function4<? super T1,? super T2,? super T3,? super T4,? extends R> f)
Narrows the givenFunction4<? super T1, ? super T2, ? super T3, ? super T4, ? extends R>
toFunction4<T1, T2, T3, T4, R>
static <T1,T2,T3,T4,R>
Function4<T1,T2,T3,T4,R>of(Function4<T1,T2,T3,T4,R> methodReference)
default Function4<T4,T3,T2,T1,R>
reversed()
Returns a reversed version of this function.default Function1<Tuple4<T1,T2,T3,T4>,R>
tupled()
Returns a tupled version of this function.
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Field Detail
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serialVersionUID
static final long serialVersionUID
The serial version uid.- See Also:
- Constant Field Values
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Method Detail
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constant
static <T1,T2,T3,T4,R> Function4<T1,T2,T3,T4,R> constant(R value)
Returns a function that always returns the constant value that you give in parameter.- Type Parameters:
T1
- generic parameter type 1 of the resulting functionT2
- generic parameter type 2 of the resulting functionT3
- generic parameter type 3 of the resulting functionT4
- generic parameter type 4 of the resulting functionR
- the result type- Parameters:
value
- the value to be returned- Returns:
- a function always returning the given value
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of
static <T1,T2,T3,T4,R> Function4<T1,T2,T3,T4,R> of(Function4<T1,T2,T3,T4,R> methodReference)
Creates aFunction4
based on Examples (w.l.o.g. referring to Function1):// using a lambda expression Function1<Integer, Integer> add1 = Function1.of(i -> i + 1); // using a method reference (, e.g. Integer method(Integer i) { return i + 1; }) Function1<Integer, Integer> add2 = Function1.of(this::method); // using a lambda reference Function1<Integer, Integer> add3 = Function1.of(add1::apply);
Caution: Reflection loses type information of lambda references.
// type of a lambda expression Type<?, ?> type1 = add1.getType(); // (Integer) -> Integer // type of a method reference Type<?, ?> type2 = add2.getType(); // (Integer) -> Integer // type of a lambda reference Type<?, ?> type3 = add3.getType(); // (Object) -> Object
- Type Parameters:
R
- return typeT1
- 1st argumentT2
- 2nd argumentT3
- 3rd argumentT4
- 4th argument- Parameters:
methodReference
- (typically) a method reference, e.g.Type::method
- Returns:
- a
Function4
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lift
static <T1,T2,T3,T4,R> Function4<T1,T2,T3,T4,Option<R>> lift(Function4<? super T1,? super T2,? super T3,? super T4,? extends R> partialFunction)
Lifts the givenpartialFunction
into a total function that returns anOption
result.- Type Parameters:
R
- return typeT1
- 1st argumentT2
- 2nd argumentT3
- 3rd argumentT4
- 4th argument- Parameters:
partialFunction
- a function that is not defined for all values of the domain (e.g. by throwing)- Returns:
- a function that applies arguments to the given
partialFunction
and returnsSome(result)
if the function is defined for the given arguments, andNone
otherwise.
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liftTry
static <T1,T2,T3,T4,R> Function4<T1,T2,T3,T4,Try<R>> liftTry(Function4<? super T1,? super T2,? super T3,? super T4,? extends R> partialFunction)
Lifts the givenpartialFunction
into a total function that returns anTry
result.- Type Parameters:
R
- return typeT1
- 1st argumentT2
- 2nd argumentT3
- 3rd argumentT4
- 4th argument- Parameters:
partialFunction
- a function that is not defined for all values of the domain (e.g. by throwing)- Returns:
- a function that applies arguments to the given
partialFunction
and returnsSuccess(result)
if the function is defined for the given arguments, andFailure(throwable)
otherwise.
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narrow
static <T1,T2,T3,T4,R> Function4<T1,T2,T3,T4,R> narrow(Function4<? super T1,? super T2,? super T3,? super T4,? extends R> f)
Narrows the givenFunction4<? super T1, ? super T2, ? super T3, ? super T4, ? extends R>
toFunction4<T1, T2, T3, T4, R>
- Type Parameters:
R
- return typeT1
- 1st argumentT2
- 2nd argumentT3
- 3rd argumentT4
- 4th argument- Parameters:
f
- AFunction4
- Returns:
- the given
f
instance as narrowed typeFunction4<T1, T2, T3, T4, R>
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apply
R apply(T1 t1, T2 t2, T3 t3, T4 t4)
Applies this function to 4 arguments and returns the result.- Parameters:
t1
- argument 1t2
- argument 2t3
- argument 3t4
- argument 4- Returns:
- the result of function application
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apply
default Function3<T2,T3,T4,R> apply(T1 t1)
Applies this function partially to one argument.- Parameters:
t1
- argument 1- Returns:
- a partial application of this function
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apply
default Function2<T3,T4,R> apply(T1 t1, T2 t2)
Applies this function partially to two arguments.- Parameters:
t1
- argument 1t2
- argument 2- Returns:
- a partial application of this function
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apply
default Function1<T4,R> apply(T1 t1, T2 t2, T3 t3)
Applies this function partially to three arguments.- Parameters:
t1
- argument 1t2
- argument 2t3
- argument 3- Returns:
- a partial application of this function
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arity
default int arity()
Returns the number of function arguments.- Returns:
- an int value >= 0
- See Also:
- Arity
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curried
default Function1<T1,Function1<T2,Function1<T3,Function1<T4,R>>>> curried()
Returns a curried version of this function.- Returns:
- a curried function equivalent to this.
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tupled
default Function1<Tuple4<T1,T2,T3,T4>,R> tupled()
Returns a tupled version of this function.- Returns:
- a tupled function equivalent to this.
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reversed
default Function4<T4,T3,T2,T1,R> reversed()
Returns a reversed version of this function. This may be useful in a recursive context.- Returns:
- a reversed function equivalent to this.
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memoized
default Function4<T1,T2,T3,T4,R> memoized()
Returns a memoizing version of this function, which computes the return value for given arguments only one time. On subsequent calls given the same arguments the memoized value is returned.Please note that memoizing functions do not permit
null
as single argument or return value.- Returns:
- a memoizing function equivalent to this.
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isMemoized
default boolean isMemoized()
Checks if this function is memoizing (= caching) computed values.- Returns:
- true, if this function is memoizing, false otherwise
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andThen
default <V> Function4<T1,T2,T3,T4,V> andThen(java.util.function.Function<? super R,? extends V> after)
Returns a composed function that first applies this Function4 to the given argument and then applies Functionafter
to the result.- Type Parameters:
V
- return type of after- Parameters:
after
- the function applied after this- Returns:
- a function composed of this and after
- Throws:
java.lang.NullPointerException
- if after is null
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