io.buybrain.util

Class Result<T,E extends Throwable>

java.lang.Object

io.buybrain.util.Result<T,E>

public class Result<T,E extends Throwable>
extends Object

Type that can be used to encode the result of a function, which can succeed or fail. Similar to Optional, but with an error object added for failure cases. Can conveniently deal with throwing functions without try-catch constructs.

Method Summary

Modifier and Type	Method and Description
<R> Result<R,?>	andThen(ThrowingConsumer<T> op) If the current value is OK, pass it to a consumer and return an empty OK result.
<R> Result<R,?>	andThen(ThrowingRunnable op) If the current value is OK, call a runnable and return an empty OK result.
<R> Result<R,?>	andThen(ThrowingSupplier<Result<R,?>> op) If the current value is OK, yield a new Result by calling a supplier.
Result<?,?>	andThenTry(ThrowingConsumer<T> op) If the current value is OK, pass it to a consumer and return an empty OK result.
<R> Result<R,?>	andThenTry(ThrowingRunnable op) If the current value is OK, call a runnable and return an empty OK result.
<R> Result<R,?>	andThenTry(ThrowingSupplier<R> op) If the current value is OK, yield a new Result by calling a supplier.
static <T,E extends Throwable> Result<T,E>	err(E error)
T	get()
E	getError()
T	getUnsafe()
boolean	isOk()
<R> Result<R,?>	map(ThrowingFunction<T,Result<R,?>> op) If the current value is OK, transform it into a new Result by applying a function.
Result<T,?>	mapErr(ThrowingFunction<E,Result<T,?>> op)
static <T> Result<T,?>	ok()
static <T> Result<T,?>	ok(T value)
Result<T,?>	orElse(T defaultValue) If the current value is an error, transform it into a default value.
Result<T,?>	orElse(ThrowingConsumer<E> op)
Result<T,?>	orElse(ThrowingRunnable op)
Result<T,?>	orElse(ThrowingSupplier<Result<T,?>> op)
Result<T,?>	orElseTry(ThrowingConsumer<E> op)
Result<T,?>	orElseTry(ThrowingRunnable op)
Result<T,?>	orElseTry(ThrowingSupplier<T> op)
static <T> Result<T,?>	trying(ThrowingRunnable op)
static <T> Result<T,?>	trying(ThrowingSupplier<T> op)
<R> Result<R,?>	tryMap(ThrowingFunction<T,R> op) If the current value is OK, transform it into a new Result by applying a function.
Result<T,?>	tryMapErr(ThrowingFunction<E,T> op)

Methods inherited from class java.lang.Object

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

Method Detail

map

public <R> Result<R,?> map(@NonNull
                           ThrowingFunction<T,Result<R,?>> op)

If the current value is OK, transform it into a new Result by applying a function.

Parameters:

op - the function to apply, should return a Result object

Returns:

the transformed result

Throws:

RuntimeException - if the mapping function throws

tryMap

public <R> Result<R,?> tryMap(@NonNull
                              ThrowingFunction<T,R> op)

If the current value is OK, transform it into a new Result by applying a function. The function should return the raw value type T. It will be wrapped in OK if the function returns, and any throwable thrown will be wrapped in an Error result.

Parameters:

op - the function to apply, should return the raw value that will be automatically wrapped

Returns:

the transformed result

andThen

public <R> Result<R,?> andThen(@NonNull
                               ThrowingSupplier<Result<R,?>> op)

If the current value is OK, yield a new Result by calling a supplier.

Parameters:

op - the supplier to call, should return a Result object

Returns:

the new result

Throws:

RuntimeException - if the supplier throws

andThenTry

public <R> Result<R,?> andThenTry(@NonNull
                                  ThrowingSupplier<R> op)

If the current value is OK, yield a new Result by calling a supplier. The supplier return the raw value type T. It will be wrapped in OK if the supplier returns, and any throwable thrown will be wrapped in an Error result.

Parameters:

op - the supplier to call, should return a Result object

Returns:

the new result

andThen

public <R> Result<R,?> andThen(@NonNull
                               ThrowingConsumer<T> op)

If the current value is OK, pass it to a consumer and return an empty OK result.

Parameters:

op - the consumer to call

Returns:

the new (empty) result

Throws:

RuntimeException - if the consumer throws

andThenTry

public Result<?,?> andThenTry(@NonNull
                              ThrowingConsumer<T> op)

If the current value is OK, pass it to a consumer and return an empty OK result. If the consumer throws, the error will be wrapped in an Error result.

Parameters:

op - the consumer to call

Returns:

the new (empty) result

andThen

public <R> Result<R,?> andThen(@NonNull
                               ThrowingRunnable op)

If the current value is OK, call a runnable and return an empty OK result.

Parameters:

op - the runnable to run

Returns:

the new (empty) result

Throws:

RuntimeException - if the runnable throws

andThenTry

public <R> Result<R,?> andThenTry(@NonNull
                                  ThrowingRunnable op)

If the current value is OK, call a runnable and return an empty OK result. f the runnable throws, the error will be wrapped in an Error result.

Parameters:

op - the runnable to run

Returns:

the new (empty) result

Throws:

RuntimeException - if the runnable throws

orElse

public Result<T,?> orElse(T defaultValue)

If the current value is an error, transform it into a default value.

Parameters:

defaultValue - the default value

Returns:

the new OK result wrapping the default value

mapErr

public Result<T,?> mapErr(@NonNull
                          ThrowingFunction<E,Result<T,?>> op)

tryMapErr

public Result<T,?> tryMapErr(@NonNull
                             ThrowingFunction<E,T> op)

orElse

public Result<T,?> orElse(@NonNull
                          ThrowingSupplier<Result<T,?>> op)

orElseTry

public Result<T,?> orElseTry(@NonNull
                             ThrowingSupplier<T> op)

orElse

public Result<T,?> orElse(@NonNull
                          ThrowingConsumer<E> op)

orElseTry

public Result<T,?> orElseTry(@NonNull
                             ThrowingConsumer<E> op)

orElse

public Result<T,?> orElse(@NonNull
                          ThrowingRunnable op)

orElseTry

public Result<T,?> orElseTry(@NonNull
                             ThrowingRunnable op)

get

public T get()
      throws E extends Throwable

Throws:

E extends Throwable

getUnsafe

public T getUnsafe()

getError

public E getError()

ok

public static <T> Result<T,?> ok()

trying

public static <T> Result<T,?> trying(@NonNull
                                     ThrowingSupplier<T> op)

trying

public static <T> Result<T,?> trying(@NonNull
                                     ThrowingRunnable op)

isOk

public boolean isOk()

ok

public static <T> Result<T,?> ok(T value)

err

public static <T,E extends Throwable> Result<T,E> err(@NonNull
                                                      E error)