Result (ch.awae.awaeUtils 2.1.1 API)

java.lang.Object
- ch.awae.utils.functional.Result<T>

Type Parameters:

T - the result type
```
public abstract class Result<T>
extends java.lang.Object
```
Result is designed for thorough result handling. It exists in 3 different possible states:
1. a Value Result: This represents the main result. It contains a non-null object
2. an Empty (null) Result: This represents "no result". It is the alternative for returning null
3. an Error Result: This represents a failure and contains the exception that would otherwise be thrown
All of these result types can be interacted with. They can also be used for further processing using a functional code style.
Since:

awaeUtils 1.0.0

Author:

Andreas Wälchli

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`static <T> Result<T>`	`empty()` Returns an empty result
`static <T> Result<T>`	`eval(FailableFunction0<T> supplier)` Evaluates a given expression and returns a result according to the expression result.
`abstract java.lang.Throwable`	`exception()` Returns the exception contained in the result
`abstract <E> Result<E>`	`flatMap(FailableFunction1<T,Result<E>> mapper)` Applies the mapping function to the value of the result and returns the result returned by the mapping function.
`abstract Result<T>`	`flatMapException(FailableFunction1<java.lang.Throwable,Result<T>> mapper)` Applies the mapping function to the exception and returns the result returned by it.
`abstract T`	`get()` Returns the value contained in the result
`void`	`ifEmpty(java.lang.Runnable runner)` Invokes the runnable if the result is empty
`void`	`ifErroneous(java.util.function.Consumer<java.lang.Throwable> consumer)` Evaluates the consumer with the exception if it exists
`void`	`ifPresent(java.util.function.Consumer<T> consumer)` Evaluates the consumer with the value if it exists
`abstract boolean`	`isEmpty()` Indicates if the result is an empty result.
`abstract boolean`	`isErroneous()` Indicates if the result is an error result.
`abstract boolean`	`isPresent()` Indicates if a value is present.
`abstract <E> Result<E>`	`map(FailableFunction1<T,E> mapper)` Applies the mapping function to the value of the result (if it exists).
`abstract Result<T>`	`mapException(FailableFunction1<java.lang.Throwable,T> mapper)` Applies the mapping function to the exception.
`static <T> Result<T>`	`of(T value)` Wraps a non-null value into a value result.
`static <T> Result<T>`	`ofException(java.lang.Throwable e)` Wraps an exception into an error result.
`static <T> Result<T>`	`ofNullable(T value)` Wraps a value into a value result.
`T`	`orNull()` Returns the value if it exists or `null` otherwise

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

- Method Detail
  - empty
```
public static <T> Result<T> empty()
```
    Returns an empty result
    
    Returns:
    
    an empty result
  - of
```
public static <T> Result<T> of(T value)
```
    Wraps a non-null value into a value result. If the value is null, an error result with a NullPointerException is returned.
    
    Parameters:
    
    value - the value to wrap
    
    Returns:
    
    the result containing the value
  - ofNullable
```
public static <T> Result<T> ofNullable(T value)
```
    Wraps a value into a value result. Null values are allowed. If the value is null, an empty result is returned instead of the value result.
    
    Parameters:
    
    value - the value to wrap
    
    Returns:
    
    the result containing the value
  - ofException
```
public static <T> Result<T> ofException(java.lang.Throwable e)
```
    Wraps an exception into an error result. Null values are allowed, but yield a NullPointerException wrapped inside the result.
    
    Parameters:
    
    e - the exception to wrap
    
    Returns:
    
    the result containing the exception
  - eval
```
public static <T> Result<T> eval(FailableFunction0<T> supplier)
```
    Evaluates a given expression and returns a result according to the expression result. Any exceptions thrown by the expression will be captured and wrapped into an error result. Null return values yield empty results, and non-null values yield value results.
    
    Parameters:
    
    supplier - the supplier to evaluate
    
    Returns:
    
    the result of the supplier
  - get
```
public abstract T get()
               throws java.util.NoSuchElementException
```
    Returns the value contained in the result
    
    Returns:
    
    the value
    
    Throws:
    
    java.util.NoSuchElementException - if the result is no value result
  - exception
```
public abstract java.lang.Throwable exception()
                                       throws java.util.NoSuchElementException
```
    Returns the exception contained in the result
    
    Returns:
    
    the exception
    
    Throws:
    
    java.util.NoSuchElementException - if the result is no error result
  - isPresent
```
public abstract boolean isPresent()
```
    Indicates if a value is present. This is an identifier for value results
    
    Returns:
    
    true iff the result is a value result
  - isErroneous
```
public abstract boolean isErroneous()
```
    Indicates if the result is an error result.
    
    Returns:
    
    true iff the result is an error result
  - isEmpty
```
public abstract boolean isEmpty()
```
    Indicates if the result is an empty result.
    
    Returns:
    
    true iff the result is an empty result
  - map
```
public abstract <E> Result<E> map(FailableFunction1<T,E> mapper)
```
    Applies the mapping function to the value of the result (if it exists).
    
    Parameters:
    
    mapper - the mapping function
    
    Returns:
    
    a result containing the result of the mapping operation
  - flatMap
```
public abstract <E> Result<E> flatMap(FailableFunction1<T,Result<E>> mapper)
```
    Applies the mapping function to the value of the result and returns the result returned by the mapping function. If the mapping function throws an exception, it is captured, wrapped and returned instead.
    
    Parameters:
    
    mapper - the mapping function
    
    Returns:
    
    the result of the mapping function
  - mapException
```
public abstract Result<T> mapException(FailableFunction1<java.lang.Throwable,T> mapper)
```
    Applies the mapping function to the exception.
    
    Parameters:
    
    mapper - the mapping function
    
    Returns:
    
    a result containing the result of the mapping function
  - flatMapException
```
public abstract Result<T> flatMapException(FailableFunction1<java.lang.Throwable,Result<T>> mapper)
```
    Applies the mapping function to the exception and returns the result returned by it.
    
    Parameters:
    
    mapper - the mapping function
    
    Returns:
    
    the result of the mapping function
  - ifPresent
```
public void ifPresent(java.util.function.Consumer<T> consumer)
```
    Evaluates the consumer with the value if it exists
    
    Parameters:
    
    consumer - the consumer
  - ifErroneous
```
public void ifErroneous(java.util.function.Consumer<java.lang.Throwable> consumer)
```
    Evaluates the consumer with the exception if it exists
    
    Parameters:
    
    consumer - the consumer
  - ifEmpty
```
public void ifEmpty(java.lang.Runnable runner)
```
    Invokes the runnable if the result is empty
    
    Parameters:
    
    runner - the runner
  - orNull
```
public T orNull()
```
    Returns the value if it exists or null otherwise
    
    Returns:
    
    the value or null

Class Result<T>

Method Summary

Methods inherited from class java.lang.Object

Method Detail

empty

of

ofNullable

ofException

eval

get

exception

isPresent

isErroneous

isEmpty

map

flatMap

mapException

flatMapException

ifPresent

ifErroneous

ifEmpty

orNull