io.simplesource.data

Class Result<E,A>

java.lang.Object

io.simplesource.data.Result<E,A>

Type Parameters:

E - on failure there will be a NonEmptyList of error instances with an error value of this type.

A - when successful there will be a contained value of this type.

public abstract class Result<E,A>
extends Object

A Result is either a success containing a value of the specified type, or a failure with a list value errors.

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object obj)
<F> Result<F,A>	errorMap(java.util.function.Function<E,F> errorMapper) Modifies the error type of the result, returning a new Result
static <E,S> Result<E,S>	failure(E error, E... errors) Factory method to creates a Failed Result from a array value of error
static <E,S> Result<E,S>	failure(NonEmptyList<E> errors) Factory method to creates a Failed Result from a {@link NonEmptyList< E >}}
Optional<NonEmptyList<E>>	failureReasons() If this is a failure, return the error reasons for that failure, if not return nothing.
<T> Result<E,T>	flatMap(java.util.function.Function<A,Result<E,T>> mapper) Runs the given function on the contents value this Result, returning a new Result with the extracted reason extracted from the functions returned Result<E, T>
abstract <T> T	fold(java.util.function.Function<NonEmptyList<E>,T> f, java.util.function.Function<A,T> s) Turn this Result into a destination type by supplying functions from the list of failure errors, or a function from the contained value.
A	getOrElse(A defaultValue) Return the value contained within this Result if the isSuccess() is true else return the default value provided.
void	ifSuccessful(java.util.function.Consumer<A> consumer) If a value is present, invoke the specified consumer with the value, otherwise do nothing.
boolean	isFailure() Return true if this Result is a failure.
abstract boolean	isSuccess() Return true if this Result is a success.
<T> Result<E,T>	map(java.util.function.Function<A,T> mapper) Runs the given function on the contents value this Result, returning a new Result with the output value the result of that function.
static <E,S> Result<E,S>	success(S s) Factory method to creates a succesful Result from a value.

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

success

public static <E,S> Result<E,S> success(S s)

Factory method to creates a succesful Result from a value.

Type Parameters:

E - The error type for failures.

S - when successful there will be a contained value this type.

Parameters:

s - value that will be lifted into this Result

Returns:

new success Result containing value provided.

failure

@SafeVarargs
public static <E,S> Result<E,S> failure(E error,
                                                     E... errors)

Factory method to creates a Failed Result from a array value of error

Type Parameters:

E - The error type for failures.

S - when successful there will be a contained value this type.

Parameters:

error - the first cause of Result to be failed

errors - a variable argument list of further causes of failure

Returns:

new failed Result containing the failed errors

failure

public static <E,S> Result<E,S> failure(NonEmptyList<E> errors)

Factory method to creates a Failed Result from a {@link NonEmptyList< E >}}

Type Parameters:

E - The error type for failures.

S - when successful there will be a contained value this type.

Parameters:

errors - what caused this Result to failed

Returns:

new failed Result containing the failed errors

isSuccess

public abstract boolean isSuccess()

Return true if this Result is a success.

Returns:

true if this Result is a success.

isFailure

public final boolean isFailure()

Return true if this Result is a failure.

Returns:

true if this Result is a failure.

getOrElse

public A getOrElse(A defaultValue)

Return the value contained within this Result if the isSuccess() is true else return the default value provided.

Parameters:

defaultValue - to return if this isSuccess() is false

Returns:

the value contained within this Result if the isSuccess() is true else return the default value provided.

fold

public abstract <T> T fold(java.util.function.Function<NonEmptyList<E>,T> f,
                           java.util.function.Function<A,T> s)

Turn this Result into a destination type by supplying functions from the list of failure errors, or a function from the contained value.

Type Parameters:

T - The target return type

Parameters:

f - a function to apply to the list of errors for failure, if any

s - a function to apply to successfully updated aggregate value

Returns:

the target type returned in either the success or the failure cases

failureReasons

public Optional<NonEmptyList<E>> failureReasons()

If this is a failure, return the error reasons for that failure, if not return nothing.

Returns:

the nonempty list of failures

map

public <T> Result<E,T> map(java.util.function.Function<A,T> mapper)

Runs the given function on the contents value this Result, returning a new Result with the output value the result of that function.

Type Parameters:

T - The new component type

Parameters:

mapper - A function

Returns:

a Result<E, T>

Throws:

NullPointerException - if mapper is null

errorMap

public <F> Result<F,A> errorMap(java.util.function.Function<E,F> errorMapper)

Modifies the error type of the result, returning a new Result

Type Parameters:

F - The new component type

Parameters:

errorMapper - The error mapping function

Returns:

a Result<E, T>

Throws:

NullPointerException - if mapper is null

flatMap

public <T> Result<E,T> flatMap(java.util.function.Function<A,Result<E,T>> mapper)

Runs the given function on the contents value this Result, returning a new Result with the extracted reason extracted from the functions returned Result<E, T>

Type Parameters:

T - The new component type

Parameters:

mapper - A mapper

Returns:

a mapped result with the new value mapped to the new type

Throws:

NullPointerException - if mapper is null

ifSuccessful

public void ifSuccessful(java.util.function.Consumer<A> consumer)

If a value is present, invoke the specified consumer with the value, otherwise do nothing.

Parameters:

consumer - The consumer to invoke

equals

public boolean equals(Object obj)

Overrides:

equals in class Object