Try (no.finn.lambda:lambda-companion 0.24 API)

java.lang.Object
- no.finn.lambdacompanion.Try<T>

Type Parameters:

T - t

Direct Known Subclasses:

Failure, Success
```
public abstract class Try<T>
extends Object
```
Try is a right-biased datatype for wrapping function calls that might fail with an Exception. A Try is alwyas Success or Failure. Success holds a value, and Failure holds an Exception. Being right biased, you can map and flatMap on it successivly, delaying handling of failure to the very end of your chain. the recover-method usually comes at the end of a call-chain and forces the handling of both success and failure.

Constructor Summary

Constructors
Constructor and Description

Try()

Constructors
Constructor and Description
`Try()`

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`static <U> Try<U>`	`failure(Exception Exception)`
`abstract Optional<Try<T>>`	`filter(Predicate<T> predicate)` Applies a filter, where a match returns Success and Failure otherwise.
`abstract <U> Try<U>`	`flatMap(ThrowingFunction<? super T,? extends Try<U>,? extends Exception> mapper)` Applies a function on two values.
`abstract void`	`forEach(ThrowingConsumer<? super T,? extends Exception> consumer)` Accepts a consuming function and applies it to the value if it is a Success.
`abstract <U> Try<U>`	`map(ThrowingFunction<? super T,? extends U,? extends Exception> mapper)` Applies a function on a value of type Success.
`static <U,V,W> Try<U>`	`of(ThrowingBiFunction<V,W,? extends U,? extends Exception> func, V v, W w)` Starting point to the Try structure.
`static <U,V> Try<U>`	`of(ThrowingFunction<V,? extends U,? extends Exception> func, V v)` Starting point to the Try structure.
`static <U> Try<U>`	`of(ThrowingSupplier<U,? extends Exception> supplier)` Starting point to the Try structure.
`abstract T`	`orElse(T defaultValue)` Returns the value of the Success, or a default value of the same type if this is a Failure.
`abstract T`	`orElseGet(Supplier<? extends T> defaultValue)` Returns the value of the Success, or lazily falls back to a supplied value of the same type
`abstract <E extends Exception> T`	`orElseRethrow()` Escapes the Try and enters a regular try-catch flow by rethowing the caught exception when a Failure
`abstract <X extends Exception,Y extends Exception> T`	`orElseThrow(Function<X,Y> ExceptionMapper)` Escapes the Try and enters a regular try-catch flow
`abstract Try<T>`	`peek(ThrowingConsumer<? super T,? extends Exception> consumer)` Same as forEach but returns the Try for further chaining
`abstract Try<T>`	`peekFailure(Consumer<Failure<T>> consumer)` Does nothing on Success, but accepts a consumer on Failure
`abstract <U> U`	`recover(Function<? super T,? extends U> successFunc, Function<Exception,? extends U> failureFunc)` Accepts two functions, the first applied if Success - returning the value, the other executed if Failure, returning a fallback value.
`static <T> Try<List<T>>`	`sequence(List<Try<T>> tries)` Creates one Try from a list of tries containing the same type, or the _first_ failure in the given list
`abstract <X extends Exception> Either<X,T>`	`toEither()` Creates an Either where the Left is the Failure and Right is the Success from this Try
`abstract Optional<T>`	`toOptional()` Creates an Optional wrapping the value if Success.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
 - Try
```
public Try()
```
- Method Detail
 - map
```
public abstract  Try map(ThrowingFunction<? super T,? extends U,? extends Exception> mapper)
```
 Applies a function on a value of type Success. Returns self if Failure.
 
 Type Parameters:
 
 U - Type of the return value of the function
 
 Parameters:
 
 mapper - Function from T to U with an Exception in the signature
 
 Returns:
 
 a new Try
 - flatMap
```
public abstract  Try flatMap(ThrowingFunction<? super T,? extends Try,? extends Exception> mapper)
```
 Applies a function on two values. Returns Success of the resulting value, or Returns self if Failure. Same as map() but needs a function ending in a Try
 
 Type Parameters:
 
 U - Type of the value to be wrapped in a Try of the function
 
 Parameters:
 
 mapper - Function from T to Try with an Exception in the signature
 
 Returns:
 
 a new Try
 - filter
```
public abstract Optional<Try<T>> filter(Predicate<T> predicate)
```
 Applies a filter, where a match returns Success and Failure otherwise.
 
 Parameters:
 
 predicate - Predicate function to determine Success or Failure
 
 Returns:
 
 the same or new try
 - forEach
```
public abstract void forEach(ThrowingConsumer<? super T,? extends Exception> consumer)
```
 Accepts a consuming function and applies it to the value if it is a Success. Does nothing if Failure.
 
 Parameters:
 
 consumer - Consuming function with an Exception in the signature
 - peek
```
public abstract Try<T> peek(ThrowingConsumer<? super T,? extends Exception> consumer)
```
 Same as forEach but returns the Try for further chaining
 
 Parameters:
 
 consumer - Consuming function with an Exception in the signature
 
 Returns:
 
 the same Try
 - peekFailure
```
public abstract Try<T> peekFailure(Consumer<Failure<T>> consumer)
```
 Does nothing on Success, but accepts a consumer on Failure
 
 Parameters:
 
 consumer - Consuming function with a failure
 
 Returns:
 
 the same Try
 - orElse
```
public abstract T orElse(T defaultValue)
```
 Returns the value of the Success, or a default value of the same type if this is a Failure. Note that the argument is always evaluated, and this is not lazy (as opposed to orElseGet)
 
 Parameters:
 
 defaultValue - default fallback value
 
 Returns:
 
 value
 - orElseGet
```
public abstract T orElseGet(Supplier<? extends T> defaultValue)
```
 Returns the value of the Success, or lazily falls back to a supplied value of the same type
 
 Parameters:
 
 defaultValue - lazy default supplier of fallback value
 
 Returns:
 
 value
 - recover
```
public abstract  U recover(Function<? super T,? extends U> successFunc,
 Function<Exception,? extends U> failureFunc)
```
 Accepts two functions, the first applied if Success - returning the value, the other executed if Failure, returning a fallback value. Note that - the first function cannot have an Exception in its signature. - the fallback function must end in a value
 
 Type Parameters:
 
 U - Type of the value
 
 Parameters:
 
 successFunc - Function handling the Success case
 
 failureFunc - Function handling the Failure case
 
 Returns:
 
 a value of type U
 - toOptional
```
public abstract Optional<T> toOptional()
```
 Creates an Optional wrapping the value if Success. Creates an empty Optional if Failure.
 
 Returns:
 
 An Optional
 - toEither
```
public abstract <X extends Exception> Either<X,T> toEither()
```
 Creates an Either where the Left is the Failure and Right is the Success from this Try
 
 Type Parameters:
 
 X - Exception
 
 Returns:
 
 an Either
 - orElseThrow
```
public abstract <X extends Exception,Y extends Exception> T orElseThrow(Function<X,Y> ExceptionMapper)
 throws Y extends Exception
```
 Escapes the Try and enters a regular try-catch flow
 
 Type Parameters:
 
 X - any Exception
 
 Y - any Exception
 
 Parameters:
 
 ExceptionMapper - Function to transform the Exception if this is a Failure
 
 Returns:
 
 Value or a transformed Exception
 
 Throws:
 
 Y - any Exception
 
 Y extends Exception
 - orElseRethrow
```
public abstract <E extends Exception> T orElseRethrow()
 throws E extends Exception
```
 Escapes the Try and enters a regular try-catch flow by rethowing the caught exception when a Failure
 
 Type Parameters:
 
 E - any Exception
 
 Returns:
 
 Value or a transformed Exception
 
 Throws:
 
 E - any Exception
 
 E extends Exception
 - of
```
public static <U,V> Try of(ThrowingFunction<V,? extends U,? extends Exception> func,
 V v)
```
 Starting point to the Try structure. Create a try from a function that throws an Exception and an argument to this function
 
 Type Parameters:
 
 U - Type of the function return value
 
 V - Type of the function argument
 
 Parameters:
 
 func - Function to be attempted, e.g. URL::new
 
 v - Argument for the function
 
 Returns:
 
 a Try
 - of
```
public static <U,V,W> Try of(ThrowingBiFunction<V,W,? extends U,? extends Exception> func,
 V v,
 W w)
```
 Starting point to the Try structure. Create a try from a function that throws an Exception and two arguments to this function
 
 Type Parameters:
 
 U - Type of the function return value
 
 V - Type of the first function argument
 
 W - Type of the second function argument
 
 Parameters:
 
 func - Function to be attempted, e.g. (a,b) -> a / b
 
 v - First argument for the function
 
 w - Second argument for the function
 
 Returns:
 
 a Try
 - of
```
public static  Try of(ThrowingSupplier<U,? extends Exception> supplier)
```
 Starting point to the Try structure. Create a try from a Supplier that throws an Exception
 
 Type Parameters:
 
 U - Type of the supplied object from the supplier function
 
 Parameters:
 
 supplier - The supplier function
 
 Returns:
 
 a Try
 - failure
```
public static  Try failure(Exception Exception)
```
 - sequence
```
public static <T> Try<List<T>> sequence(List<Try<T>> tries)
```
 Creates one Try from a list of tries containing the same type, or the _first_ failure in the given list
 
 Type Parameters:
 
 T - the type
 
 Parameters:
 
 tries - List of tries
 
 Returns:
 
 One Try containing a list of Ts

Class Try<T>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Try

Method Detail

map

flatMap

filter

forEach

peek

peekFailure

orElse

orElseGet

recover

toOptional

toEither

orElseThrow

orElseRethrow

of

of

of

failure

sequence