Function4 (Vavr 0.9.1 API)

Type Parameters:

T1 - argument 1 of the function

T2 - argument 2 of the function

T3 - argument 3 of the function

T4 - argument 4 of the function

R - return type of the function

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>
```
Represents a function with 4 arguments.

Author:

Daniel Dietrich

Nested Class Summary

Nested Classes
Modifier and Type Interface and Description

static interface Lambda.Memoized
Zero Abstract Method (ZAM) interface for marking functions as memoized using intersection types.

Nested Classes
Modifier and Type	Interface and Description
`static interface`	`Lambda.Memoized` Zero Abstract Method (ZAM) interface for marking functions as memoized using intersection types.

Field Summary

Fields
Modifier and Type Field and Description

static long serialVersionUID
The serial version uid.

Fields
Modifier and Type	Field and Description
`static long`	`serialVersionUID` The serial version uid.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method and 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 Function `after` 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()`
`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 given `partialFunction` into a total function that returns an `Option` 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 given `partialFunction` into a total function that returns an `Try` 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 given `Function4<? super T1, ? super T2, ? super T3, ? super T4, ? extends R>` to `Function4<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)` Creates a `Function4` based on method reference lambda expression Examples (w.l.o.g.
`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.

- Field Detail
  - serialVersionUID
```
static final long serialVersionUID
```
    The serial version uid.
    
    See Also:
    
    Constant Field Values
- Method Detail
  - of
```
static <T1,T2,T3,T4,R> Function4<T1,T2,T3,T4,R> of(Function4<T1,T2,T3,T4,R> methodReference)
```
    Creates a Function4 based on
    - method reference
    - lambda expression
    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 type
    
    T1 - 1st argument
    
    T2 - 2nd argument
    
    T3 - 3rd argument
    
    T4 - 4th argument
    
    Parameters:
    
    methodReference - (typically) a method reference, e.g. Type::method
    
    Returns:
    
    a Function4
  - 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 given partialFunction into a total function that returns an Option result.
    
    Type Parameters:
    
    R - return type
    
    T1 - 1st argument
    
    T2 - 2nd argument
    
    T3 - 3rd argument
    
    T4 - 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 returns Some(result) if the function is defined for the given arguments, and None otherwise.
  - 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 given partialFunction into a total function that returns an Try result.
    
    Type Parameters:
    
    R - return type
    
    T1 - 1st argument
    
    T2 - 2nd argument
    
    T3 - 3rd argument
    
    T4 - 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 returns Success(result) if the function is defined for the given arguments, and Failure(throwable) otherwise.
  - 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 given Function4<? super T1, ? super T2, ? super T3, ? super T4, ? extends R> to Function4<T1, T2, T3, T4, R>
    
    Type Parameters:
    
    R - return type
    
    T1 - 1st argument
    
    T2 - 2nd argument
    
    T3 - 3rd argument
    
    T4 - 4th argument
    
    Parameters:
    
    f - A Function4
    
    Returns:
    
    the given f instance as narrowed type Function4<T1, T2, T3, T4, R>
  - apply
```
R apply(T1 t1,
        T2 t2,
        T3 t3,
        T4 t4)
```
    Applies this function to 4 arguments and returns the result.
    
    Parameters:
    
    t1 - argument 1
    
    t2 - argument 2
    
    t3 - argument 3
    
    t4 - argument 4
    
    Returns:
    
    the result of function application
  - 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
  - apply
```
default Function2<T3,T4,R> apply(T1 t1,
                                 T2 t2)
```
    Applies this function partially to two arguments.
    
    Parameters:
    
    t1 - argument 1
    
    t2 - argument 2
    
    Returns:
    
    a partial application of this function
  - apply
```
default Function1<T4,R> apply(T1 t1,
                              T2 t2,
                              T3 t3)
```
    Applies this function partially to three arguments.
    
    Parameters:
    
    t1 - argument 1
    
    t2 - argument 2
    
    t3 - argument 3
    
    Returns:
    
    a partial application of this function
  - arity
```
default int arity()
```
    Returns:
    
    the number of function arguments.
    
    See Also:
    
    Arity
  - 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 function
    
    T2 - generic parameter type 2 of the resulting function
    
    T3 - generic parameter type 3 of the resulting function
    
    T4 - generic parameter type 4 of the resulting function
    
    R - the result type
    
    Parameters:
    
    value - the value to be returned
    
    Returns:
    
    a function always returning the given value
  - 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.
  - tupled
```
default Function1<Tuple4<T1,T2,T3,T4>,R> tupled()
```
    Returns a tupled version of this function.
    
    Returns:
    
    a tupled function equivalent to this.
  - 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.
  - 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.
  - 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 Function after 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
  - isMemoized
```
default boolean isMemoized()
```
    Checks if this function is memoizing (= caching) computed values.
    
    Returns:
    
    true, if this function is memoizing, false otherwise

Interface Function4<T1,T2,T3,T4,R>

Nested Class Summary

Field Summary

Method Summary

Field Detail

serialVersionUID

Method Detail

of

lift

liftTry

narrow

apply

apply

apply

apply

arity

constant

curried

tupled

reversed

memoized

andThen

isMemoized