R
- return type of the function@FunctionalInterface public interface CheckedFunction0<R> extends λ<R>
λ.Memoized
Modifier and Type | Field and Description |
---|---|
static long |
serialVersionUID
The serial version uid.
|
Modifier and Type | Method and Description |
---|---|
default <V> CheckedFunction0<V> |
andThen(CheckedFunction1<? super R,? extends V> after)
Returns a composed function that first applies this CheckedFunction0 to the given argument and then applies
CheckedFunction1
after to the result. |
R |
apply()
Applies this function to no arguments and returns the result.
|
default int |
arity() |
static <R> CheckedFunction0<R> |
constant(R value)
Returns a function that always returns the constant
value that you give in parameter.
|
default CheckedFunction0<R> |
curried()
Returns a curried version of this function.
|
static <R> Function0<Option<R>> |
lift(CheckedFunction0<? extends R> partialFunction)
Lifts the given
partialFunction into a total function that returns an Option result. |
static <R> Function0<Try<R>> |
liftTry(CheckedFunction0<? extends R> partialFunction)
Lifts the given
partialFunction into a total function that returns an Try result. |
default CheckedFunction0<R> |
memoized()
Returns a memoizing version of this function, which computes the return value for given arguments only one time.
|
static <R> CheckedFunction0<R> |
of(CheckedFunction0<R> methodReference)
|
default Function0<R> |
recover(Function<? super Throwable,? extends Supplier<? extends R>> recover)
Return a composed function that first applies this CheckedFunction0 to the given arguments and in case of throwable
try to get value from
recover function with same arguments and throwable information. |
default CheckedFunction0<R> |
reversed()
Returns a reversed version of this function.
|
default CheckedFunction1<Tuple0,R> |
tupled()
Returns a tupled version of this function.
|
default Function0<R> |
unchecked()
Return unchecked function that will return this CheckedFunction0 result in correct case and throw exception
wrapped by
IllegalStateException in case of throwable. |
default Function0<R> |
unchecked(Function<? super Throwable,? extends RuntimeException> exceptionMapper)
Return unchecked function that will return this CheckedFunction0 result in correct case and throw runtime exception
wrapped by
exceptionMapper in case of throwable |
isMemoized
static final long serialVersionUID
static <R> CheckedFunction0<R> of(CheckedFunction0<R> methodReference)
CheckedFunction0
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
R
- return typemethodReference
- (typically) a method reference, e.g. Type::method
CheckedFunction0
static <R> Function0<Option<R>> lift(CheckedFunction0<? extends R> partialFunction)
partialFunction
into a total function that returns an Option
result.R
- return typepartialFunction
- a function that is not defined for all values of the domain (e.g. by throwing)partialFunction
and returns Some(result)
if the function is defined for the given arguments, and None
otherwise.static <R> Function0<Try<R>> liftTry(CheckedFunction0<? extends R> partialFunction)
partialFunction
into a total function that returns an Try
result.R
- return typepartialFunction
- a function that is not defined for all values of the domain (e.g. by throwing)partialFunction
and returns Success(result)
if the function is defined for the given arguments, and Failure(throwable)
otherwise.R apply() throws Throwable
Throwable
- if something goes wrong applying this function to the given argumentsdefault int arity()
static <R> CheckedFunction0<R> constant(R value)
R
- the result typevalue
- the value to be returneddefault CheckedFunction0<R> curried()
λ
default CheckedFunction1<Tuple0,R> tupled()
λ
default CheckedFunction0<R> reversed()
λ
default CheckedFunction0<R> memoized()
λ
Please note that memoizing functions do not permit null
as single argument or return value.
default Function0<R> recover(Function<? super Throwable,? extends Supplier<? extends R>> recover)
recover
function with same arguments and throwable information.recover
- the function applied in case of throwableNullPointerException
- if recover is nulldefault Function0<R> unchecked(Function<? super Throwable,? extends RuntimeException> exceptionMapper)
exceptionMapper
in case of throwableexceptionMapper
- the function that convert function Throwable
into subclass of RuntimeException
RuntimeException
issued by the given exceptionMapper
in the case of a failuredefault Function0<R> unchecked()
IllegalStateException
in case of throwable.IllegalStateException
in the case of a failuredefault <V> CheckedFunction0<V> andThen(CheckedFunction1<? super R,? extends V> after)
after
to the result.V
- return type of afterafter
- the function applied after thisNullPointerException
- if after is nullCopyright © 2016. All Rights Reserved.