Type Parameters:

V - The value type of the Result.
```
public interface Result<V>
```
The Result type is an alternative way of chaining together functions in a functional programming style while hiding away error handling structures such as try-catch-blocks and conditionals.
Instead of adding a throws declaration to a function, the return type of the function is instead set to Result
where V is the original return type, i.e. the "happy case" and String is the error type.

Example:
```
 public Result divide(int a, int b) {
 if (b == 0) {
 return Result.err("Can't divide by zero!");
 } else {
 return Result.ok(a / b);
 }
 }
 
```

Method Summary

All Methods Static Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`accept(aQute.bnd.exceptions.ConsumerWithException<? super V> ok, aQute.bnd.exceptions.ConsumerWithException<? super java.lang.String> err)`	Processes the result.
`<U> Result<U>`	`asError()`	If an `Err`, return this coerced to the desired generic type.
`static <V> Result<V>`	`err(java.lang.CharSequence error)`	Returns an `Err` containing the specified `error`.
`static <V> Result<V>`	`err(java.lang.String format, java.lang.Object... args)`
`java.util.Optional<java.lang.String>`	`error()`	Returns the error of this instance as an `Optional`.
`<U> Result<U>`	`flatMap(aQute.bnd.exceptions.FunctionWithException<? super V,? extends Result<? extends U>> mapper)`	FlatMap the contained value if this is an `Ok` value.
`boolean`	`isErr()`	Returns `true` if this instance represents an `Err` value, `false` otherwise.
`boolean`	`isOk()`	Returns `true` if this instance represents an `Ok` value, `false` otherwise.
`<U> Result<U>`	`map(aQute.bnd.exceptions.FunctionWithException<? super V,? extends U> mapper)`	Map the contained value if this is an `Ok` value.
`Result<V>`	`mapErr(aQute.bnd.exceptions.FunctionWithException<? super java.lang.String,? extends java.lang.CharSequence> mapper)`	Map the contained error if this is an `Err` value.
`static <V> Result<V>`	`of(V value, java.lang.CharSequence error)`	Returns an `Ok` if the `value` parameter is non-`null` or an `Err` otherwise.
`static <V> Result<V>`	`ok(V value)`	Returns an `Ok` containing the specified `value`.
`V`	`orElse(V orElse)`	Returns the contained value if this is an `Ok` value.
`V`	`orElseGet(aQute.bnd.exceptions.SupplierWithException<? extends V> orElseSupplier)`	Returns the contained value if this is an `Ok` value.
`<R extends java.lang.Throwable> V`	`orElseThrow(aQute.bnd.exceptions.FunctionWithException<? super java.lang.String,? extends R> throwableSupplier)`	Returns the contained value if this is an `Ok` value.
`Result<V>`	`recover(aQute.bnd.exceptions.FunctionWithException<? super java.lang.String,? extends V> recover)`	Recover the contained error if this is an `Err` value.
`Result<V>`	`recoverWith(aQute.bnd.exceptions.FunctionWithException<? super java.lang.String,? extends Result<? extends V>> recover)`	Recover the contained error if this is an `Err` value.
`V`	`unwrap()`	Returns the contained value if this is an `Ok` value.
`V`	`unwrap(java.lang.CharSequence message)`	Express the expectation that this object is an `Ok` value.
`java.util.Optional<V>`	`value()`	Returns the value of this instance as an `Optional`.

- Method Detail
 - of
```
static <V> Result<V> of(V value,
 java.lang.CharSequence error)
```
 Returns an Ok if the value parameter is non-null or an Err otherwise. At least one of value or error must be non-null.
 
 Type Parameters:
 
 V - The value type of the Result.
 
 Parameters:
 
 value - If value is non-null, an Ok result is returned with the specified value.
 
 error - If value is null, an Err result is returned with the specified error.
 
 Returns:
 
 An Ok if the value parameter is non-null or an Err otherwise.
 - ok
```
static <V> Result<V> ok(V value)
```
 Returns an Ok containing the specified value.
 
 Type Parameters:
 
 V - The value type of the Result.
 
 Parameters:
 
 value - The value to contain in the Ok result. May be null.
 
 Returns:
 
 An Ok result.
 - err
```
static <V> Result<V> err(java.lang.CharSequence error)
```
 Returns an Err containing the specified error.
 
 Type Parameters:
 
 V - The value type of the Result.
 
 Parameters:
 
 error - The error to contain in the Err result. Must not be null.
 
 Returns:
 
 An Err result.
 - err
```
static <V> Result<V> err(java.lang.String format,
 java.lang.Object... args)
```
 - isOk
```
boolean isOk()
```
 Returns true if this instance represents an Ok value, false otherwise.
 
 Returns:
 
 true if this instance represents an Ok value, false otherwise.
 - isErr
```
boolean isErr()
```
 Returns true if this instance represents an Err value, false otherwise.
 
 Returns:
 
 true if this instance represents an Err value, false otherwise.
 - value
```
java.util.Optional<V> value()
```
 Returns the value of this instance as an Optional. Returns Optional.empty() if this is an Err instance.
 
 Returns:
 
 The value of this instance as an Optional. Returns Optional.empty() if this is an Err instance.
 - error
```
java.util.Optional<java.lang.String> error()
```
 Returns the error of this instance as an Optional. Returns Optional.empty() if this is an Ok instance.
 
 Returns:
 
 The error of this instance as an Optional. Returns Optional.empty() if this is an Ok instance.
 - unwrap
```
V unwrap()
```
 Returns the contained value if this is an Ok value. Otherwise throws a ResultException.
 
 Returns:
 
 The contained value
 
 Throws:
 
 ResultException - If this is an Err instance.
 - unwrap
```
V unwrap(java.lang.CharSequence message)
```
 Express the expectation that this object is an Ok value. Otherwise throws a ResultException with the specified message.
 
 Parameters:
 
 message - The message to pass to a potential ResultException. Must not be null.
 
 Throws:
 
 ResultException - If this is an Err instance.
 - orElse
```
V orElse(V orElse)
```
 Returns the contained value if this is an Ok value. Otherwise returns the specified alternate value.
 
 Parameters:
 
 orElse - The value to return if this is an Err instance.
 
 Returns:
 
 The contained value or the alternate value
 - orElseGet
```
V orElseGet(aQute.bnd.exceptions.SupplierWithException<? extends V> orElseSupplier)
```
 Returns the contained value if this is an Ok value. Otherwise returns the alternate value supplied by the specified supplier.
 
 Parameters:
 
 orElseSupplier - The supplier to supply an alternate value if this is an Err instance. Must not be null.
 
 Returns:
 
 The contained value or the alternate value
 - orElseThrow
```
<R extends java.lang.Throwable> V orElseThrow(aQute.bnd.exceptions.FunctionWithException<? super java.lang.String,? extends R> throwableSupplier)
 throws R extends java.lang.Throwable
```
 Returns the contained value if this is an Ok value. Otherwise throws the exception supplied by the specified function.
 
 Type Parameters:
 
 R - The exception type.
 
 Parameters:
 
 throwableSupplier - The supplier to supply an exception if this is an Err instance. Must not be null. The supplier must return a non-null result.
 
 Returns:
 
 The contained value.
 
 Throws:
 
 R - The exception returned by the throwableSupplier if this is an Err instance.
 
 R extends java.lang.Throwable
 - map
```
 Result map(aQute.bnd.exceptions.FunctionWithException<? super V,? extends U> mapper)
```
 Map the contained value if this is an Ok value. Otherwise return this.
 
 Type Parameters:
 
 U - The new value type.
 
 Parameters:
 
 mapper - The function to map the contained value into a new value. Must not be null.
 
 Returns:
 
 A result containing the mapped value if this is an Ok value. Otherwise this.
 - mapErr
```
Result<V> mapErr(aQute.bnd.exceptions.FunctionWithException<? super java.lang.String,? extends java.lang.CharSequence> mapper)
```
 Map the contained error if this is an Err value. Otherwise return this.
 
 Parameters:
 
 mapper - The function to map the contained error into a new error. Must not be null. The function must return a non-null error.
 
 Returns:
 
 A result containing the mapped error if this is an Err value. Otherwise this.
 - flatMap
```
 Result flatMap(aQute.bnd.exceptions.FunctionWithException<? super V,? extends Result<? extends U>> mapper)
```
 FlatMap the contained value if this is an Ok value. Otherwise return this.
 
 Type Parameters:
 
 U - The new value type.
 
 Parameters:
 
 mapper - The function to flatmap the contained value into a new result. Must not be null. The function must return a non-null result.
 
 Returns:
 
 The flatmapped result if this is an Ok value. Otherwise this.
 - recover
```
Result<V> recover(aQute.bnd.exceptions.FunctionWithException<? super java.lang.String,? extends V> recover)
```
 Recover the contained error if this is an Err value. Otherwise return this.
 To recover with a recovery value of null, the recoverWith(FunctionWithException) method must be used. The specified function for recoverWith(FunctionWithException) can return Result.ok(null) to supply the desired null value.
 
 Parameters:
 
 recover - The function to recover the contained error into a new value. Must not be null.
 
 Returns:
 
 A result containing the new non-null value if this is an Err value. Otherwise this if this is an Ok value or the recover function returned null.
 - recoverWith
```
Result<V> recoverWith(aQute.bnd.exceptions.FunctionWithException<? super java.lang.String,? extends Result<? extends V>> recover)
```
 Recover the contained error if this is an Err value. Otherwise return this.
 
 Parameters:
 
 recover - The function to recover the contained error into a new result. Must not be null. The function must return a non-null value.
 
 Returns:
 
 A result if this is an Err value. Otherwise this.
 - accept
```
void accept(aQute.bnd.exceptions.ConsumerWithException<? super V> ok,
 aQute.bnd.exceptions.ConsumerWithException<? super java.lang.String> err)
```
 Processes the result.
 
 Parameters:
 
 ok - The consumer called this result is an Ok value. Must not be null.
 
 err - The consumer called when this result is an Err value. Must not be null.
 - asError
```
 Result asError()
```
 If an Err, return this coerced to the desired generic type.
 
 Type Parameters:
 
 U - The desired generic type of the Err.
 
 Returns:
 
 this
 
 Throws:
 
 ResultException - If this is an Ok instance.

Interface Result<V>

Method Summary

Method Detail

of

ok

err

err

isOk

isErr

value

error

unwrap

unwrap

orElse

orElseGet

orElseThrow

map

mapErr

flatMap

recover

recoverWith

accept

asError