CheckedFunction1 (vavr 1.0.0-alpha-4 API)

Type Parameters:

T1 - argument 1 of the function

R - 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 CheckedFunction1<T1,R>
extends java.io.Serializable
```
Represents a function with one argument.

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> CheckedFunction1<T1,V>`	`andThen(CheckedFunction1<? super R,? extends V> after)` Returns a composed function that first applies this CheckedFunction1 to the given argument and then applies CheckedFunction1 `after` to the result.
`R`	`apply(T1 t1)` Applies this function to one argument and returns the result.
`default int`	`arity()` Returns the number of function arguments.
`default <V> CheckedFunction1<V,R>`	`compose(CheckedFunction1<? super V,? extends T1> before)` Returns a composed function that first applies the CheckedFunction1 `before` the given argument and then applies this CheckedFunction1 to the result.
`static <T1,R> CheckedFunction1<T1,R>`	`constant(R value)` Returns a function that always returns the constant value that you give in parameter.
`default CheckedFunction1<T1,R>`	`curried()` Returns a curried version of this function.
`static <T> CheckedFunction1<T,T>`	`identity()` Returns the identity CheckedFunction1, i.e.
`default boolean`	`isMemoized()` Checks if this function is memoizing (= caching) computed values.
`static <T1,R> Function1<T1,Option<R>>`	`lift(CheckedFunction1<? super T1,? extends R> partialFunction)` Lifts the given `partialFunction` into a total function that returns an `Option` result.
`static <T1,R> Function1<T1,Try<R>>`	`liftTry(CheckedFunction1<? super T1,? extends R> partialFunction)` Lifts the given `partialFunction` into a total function that returns an `Try` result.
`default CheckedFunction1<T1,R>`	`memoized()` Returns a memoizing version of this function, which computes the return value for given arguments only one time.
`static <T1,R> CheckedFunction1<T1,R>`	`narrow(CheckedFunction1<? super T1,? extends R> f)` Narrows the given `CheckedFunction1<? super T1, ? extends R>` to `CheckedFunction1<T1, R>`
`static <T1,R> CheckedFunction1<T1,R>`	`of(CheckedFunction1<T1,R> methodReference)` Creates a `CheckedFunction1` based on method reference lambda expression Examples (w.l.o.g.
`default Function1<T1,R>`	`recover(java.util.function.Function<? super java.lang.Throwable,? extends java.util.function.Function<? super T1,? extends R>> recover)` Return a composed function that first applies this CheckedFunction1 to the given arguments and in case of throwable try to get value from `recover` function with same arguments and throwable information.
`default CheckedFunction1<T1,R>`	`reversed()` Returns a reversed version of this function.
`default CheckedFunction1<Tuple1<T1>,R>`	`tupled()` Returns a tupled version of this function.
`default Function1<T1,R>`	`unchecked()` Returns an unchecked function that will sneaky throw if an exceptions occurs when applying the function.

- Field Detail
  - serialVersionUID
```
static final long serialVersionUID
```
    The serial version uid.
    
    See Also:
    
    Constant Field Values
- Method Detail
  - constant
```
static <T1,R> CheckedFunction1<T1,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
    
    R - the result type
    
    Parameters:
    
    value - the value to be returned
    
    Returns:
    
    a function always returning the given value
  - of
```
static <T1,R> CheckedFunction1<T1,R> of(CheckedFunction1<T1,R> methodReference)
```
    Creates a CheckedFunction1 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
    
    Parameters:
    
    methodReference - (typically) a method reference, e.g. Type::method
    
    Returns:
    
    a CheckedFunction1
  - lift
```
static <T1,R> Function1<T1,Option<R>> lift(CheckedFunction1<? super T1,? extends R> partialFunction)
```
    Lifts the given partialFunction into a total function that returns an Option result.
    
    Type Parameters:
    
    R - return type
    
    T1 - 1st 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,R> Function1<T1,Try<R>> liftTry(CheckedFunction1<? super T1,? extends R> partialFunction)
```
    Lifts the given partialFunction into a total function that returns an Try result.
    
    Type Parameters:
    
    R - return type
    
    T1 - 1st 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,R> CheckedFunction1<T1,R> narrow(CheckedFunction1<? super T1,? extends R> f)
```
    Narrows the given CheckedFunction1<? super T1, ? extends R> to CheckedFunction1<T1, R>
    
    Type Parameters:
    
    R - return type
    
    T1 - 1st argument
    
    Parameters:
    
    f - A CheckedFunction1
    
    Returns:
    
    the given f instance as narrowed type CheckedFunction1<T1, R>
  - identity
```
static <T> CheckedFunction1<T,T> identity()
```
    Returns the identity CheckedFunction1, i.e. the function that returns its input.
    
    Type Parameters:
    
    T - argument type (and return type) of the identity function
    
    Returns:
    
    the identity CheckedFunction1
  - apply
```
R apply(T1 t1)
 throws java.lang.Throwable
```
    Applies this function to one argument and returns the result.
    
    Parameters:
    
    t1 - argument 1
    
    Returns:
    
    the result of function application
    
    Throws:
    
    java.lang.Throwable - if something goes wrong applying this function to the given arguments
  - arity
```
default int arity()
```
    Returns the number of function arguments.
    
    Returns:
    
    an int value >= 0
    
    See Also:
    
    Arity
  - curried
```
default CheckedFunction1<T1,R> curried()
```
    Returns a curried version of this function.
    
    Returns:
    
    a curried function equivalent to this.
  - tupled
```
default CheckedFunction1<Tuple1<T1>,R> tupled()
```
    Returns a tupled version of this function.
    
    Returns:
    
    a tupled function equivalent to this.
  - reversed
```
default CheckedFunction1<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 CheckedFunction1<T1,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.
  - isMemoized
```
default boolean isMemoized()
```
    Checks if this function is memoizing (= caching) computed values.
    
    Returns:
    
    true, if this function is memoizing, false otherwise
  - recover
```
default Function1<T1,R> recover(java.util.function.Function<? super java.lang.Throwable,? extends java.util.function.Function<? super T1,? extends R>> recover)
```
    Return a composed function that first applies this CheckedFunction1 to the given arguments and in case of throwable try to get value from recover function with same arguments and throwable information.
    
    Parameters:
    
    recover - the function applied in case of throwable
    
    Returns:
    
    a function composed of this and recover
    
    Throws:
    
    java.lang.NullPointerException - if recover is null
  - unchecked
```
default Function1<T1,R> unchecked()
```
    Returns an unchecked function that will sneaky throw if an exceptions occurs when applying the function.
    
    Returns:
    
    a new Function1 that throws a Throwable.
  - andThen
```
default <V> CheckedFunction1<T1,V> andThen(CheckedFunction1<? super R,? extends V> after)
```
    Returns a composed function that first applies this CheckedFunction1 to the given argument and then applies CheckedFunction1 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
  - compose
```
default <V> CheckedFunction1<V,R> compose(CheckedFunction1<? super V,? extends T1> before)
```
    Returns a composed function that first applies the CheckedFunction1 before the given argument and then applies this CheckedFunction1 to the result.
    
    Type Parameters:
    
    V - argument type of before
    
    Parameters:
    
    before - the function applied before this
    
    Returns:
    
    a function composed of before and this
    
    Throws:
    
    java.lang.NullPointerException - if before is null

Interface CheckedFunction1<T1,R>

Field Summary

Method Summary

Field Detail

serialVersionUID

Method Detail

constant

of

lift

liftTry

narrow

identity

apply

arity

curried

tupled

reversed

memoized

isMemoized

recover

unchecked

andThen

compose