de.esoco.coroutine.step

Class Condition<I,O>

java.lang.Object

org.obrel.core.RelatedObject

de.esoco.coroutine.CoroutineStep<I,O>

de.esoco.coroutine.step.Condition<I,O>

All Implemented Interfaces:

de.esoco.lib.property.Fluent<CoroutineStep<I,O>>, org.obrel.core.FluentRelatable<CoroutineStep<I,O>>, org.obrel.core.Relatable

public class Condition<I,O>
extends CoroutineStep<I,O>

A Coroutine step that test a logical expression in the form of a Predicate or BiPredicate and executes certain steps (which may be a subroutines) based on the boolean result.

Constructor Summary

Constructors

Constructor and Description
Condition(java.util.function.BiPredicate<? super I,Continuation<?>> pCondition, CoroutineStep<I,O> rRunIfTrue, CoroutineStep<I,O> rRunIfFalse) Creates a new instance.

Method Summary

Modifier and Type	Method and Description
static <I,O> Condition<I,O>	doIf(java.util.function.BiPredicate<? super I,Continuation<?>> fCondition, CoroutineStep<I,O> rRunIfTrue) Tests a logical condition and executes a certain step if the condition is TRUE.
static <I,O> Condition<I,O>	doIf(java.util.function.Predicate<? super I> fCondition, CoroutineStep<I,O> rRunIfTrue) Tests a logical condition and executes a certain step if the condition is TRUE.
static <I,O> Condition<I,O>	doIfElse(java.util.function.BiPredicate<? super I,Continuation<?>> fCondition, CoroutineStep<I,O> rRunIfTrue, CoroutineStep<I,O> rRunIfFalse) Tests a logical condition and executes certain steps if the condition is either TRUE or FALSE.
static <I,O> Condition<I,O>	doIfElse(java.util.function.Predicate<? super I> fCondition, CoroutineStep<I,O> rRunIfTrue, CoroutineStep<I,O> rRunIfFalse) Tests a logical condition and executes certain steps if the condition is either TRUE or FALSE.
protected O	execute(I rInput, Continuation<?> rContinuation) This method must be implemented by subclasses to provide the actual functionality of this step.
Condition<I,O>	orElse(CoroutineStep<I,O> rRunIfFalse) Returns a new instance with the condition and TRUE step of this and a certain step to execute if the condition is FALSE.
void	runAsync(java.util.concurrent.CompletableFuture<I> fPreviousExecution, CoroutineStep<O,?> rNextStep, Continuation<?> rContinuation) Runs this execution step asynchronously as a continuation of a previous code execution in a CompletableFuture and proceeds to the next step afterwards.

Methods inherited from class de.esoco.coroutine.CoroutineStep

fail, runBlocking, terminateCoroutine, toString

Methods inherited from class org.obrel.core.RelatedObject

deleteRelation, get, getRelation, getRelations, notifyRelationListeners, readRelations, relationsEqual, relationsHashCode, relationsString, set, set, transform, writeRelations

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.obrel.core.FluentRelatable

with, with, with

Methods inherited from interface org.obrel.core.Relatable

deleteRelation, deleteRelation, deleteRelations, get, get, get, getAll, getRelation, getRelationCount, getRelations, getRelations, hasFlag, hasRelation, hasRelations, init, set, set, set, set, set, streamRelations, transform

Methods inherited from interface de.esoco.lib.property.Fluent

_with

Constructor Detail

Condition

public Condition(java.util.function.BiPredicate<? super I,Continuation<?>> pCondition,
                 CoroutineStep<I,O> rRunIfTrue,
                 CoroutineStep<I,O> rRunIfFalse)

Creates a new instance.

Parameters:

pCondition - The condition to test

rRunIfTrue - The step to run if the condition is TRUE

rRunIfFalse - The step to run if the condition is FALSE

Method Detail

doIf

public static <I,O> Condition<I,O> doIf(java.util.function.Predicate<? super I> fCondition,
                                        CoroutineStep<I,O> rRunIfTrue)

Tests a logical condition and executes a certain step if the condition is TRUE. To create a condition that also runs a step if the condition is FALSE either a subsequent call to orElse(CoroutineStep) or the alternative method doIfElse(Predicate, CoroutineStep, CoroutineStep)can be used. If no 'else' step is set the coroutine will terminate if the condition is not met.

This variant expects a unary predicate that only receives the input value. If the Continuation needs to be tested too the method doIf(BiPredicate, CoroutineStep) can be used instead.

Parameters:

fCondition - The condition to test

rRunIfTrue - The step to run if the condition is TRUE

Returns:

The new conditional step

doIf

public static <I,O> Condition<I,O> doIf(java.util.function.BiPredicate<? super I,Continuation<?>> fCondition,
                                        CoroutineStep<I,O> rRunIfTrue)

Tests a logical condition and executes a certain step if the condition is TRUE. To create a condition that also runs a step if the condition is FALSE either a subsequent call to orElse(CoroutineStep) or the alternative method doIfElse(Predicate, CoroutineStep, CoroutineStep)can be used. If no 'else' step is set the coroutine will terminate if the condition is not met.

This variant expects a binary predicate that also receives the current Continuation. If a test of the input value is sufficient the method doIf(Predicate, CoroutineStep) can be used instead.

Parameters:

fCondition - The condition to test

rRunIfTrue - The step to run if the condition is TRUE

Returns:

The new conditional step

doIfElse

public static <I,O> Condition<I,O> doIfElse(java.util.function.BiPredicate<? super I,Continuation<?>> fCondition,
                                            CoroutineStep<I,O> rRunIfTrue,
                                            CoroutineStep<I,O> rRunIfFalse)

Tests a logical condition and executes certain steps if the condition is either TRUE or FALSE. A semantic alternative is the factory method doIf(BiPredicate, CoroutineStep) in conjunction with the instance method orElse(CoroutineStep).

This variant expects a binary predicate that also receives the current Continuation. If a test of the input value is sufficient the method doIfElse(Predicate, CoroutineStep, CoroutineStep) can be used instead.

Parameters:

fCondition - The condition to test

rRunIfTrue - The step to run if the condition is TRUE

rRunIfFalse - The step to run if the condition is FALSE

Returns:

The new conditional step

doIfElse

public static <I,O> Condition<I,O> doIfElse(java.util.function.Predicate<? super I> fCondition,
                                            CoroutineStep<I,O> rRunIfTrue,
                                            CoroutineStep<I,O> rRunIfFalse)

Tests a logical condition and executes certain steps if the condition is either TRUE or FALSE. A semantic alternative is the factory method doIf(BiPredicate, CoroutineStep) in conjunction with the instance method orElse(CoroutineStep).

This variant expects a unary predicate that only receives the input value. If the Continuation needs to be tested too the method doIf(BiPredicate, CoroutineStep) can be used instead.

Parameters:

fCondition - The condition to test

rRunIfTrue - The step to run if the condition is TRUE

rRunIfFalse - The step to run if the condition is FALSE

Returns:

The new conditional step

orElse

public Condition<I,O> orElse(CoroutineStep<I,O> rRunIfFalse)

Returns a new instance with the condition and TRUE step of this and a certain step to execute if the condition is FALSE. This is just a semantic alternative to doIfElse(BiPredicate, CoroutineStep, CoroutineStep).

Parameters:

rRunIfFalse - The step to run if the condition is FALSE

Returns:

A new conditional step

runAsync

public void runAsync(java.util.concurrent.CompletableFuture<I> fPreviousExecution,
                     CoroutineStep<O,?> rNextStep,
                     Continuation<?> rContinuation)

Runs this execution step asynchronously as a continuation of a previous code execution in a CompletableFuture and proceeds to the next step afterwards.

Subclasses that need to suspend the invocation of the next step until some condition is met (e.g. sending or receiving data has finished) need to override this method and create a Suspension by invoking Continuation.suspend(CoroutineStep, CoroutineStep) on the next step. If the condition that caused the suspension resolves the coroutine execution can be resumed by calling Suspension.resume(Object).

Subclasses that override this method also need to handle errors by terminating any further execution (i.e. not resuming a suspension if such exists) and forwarding the causing exception to Continuation.fail(Throwable).

Overrides:

runAsync in class CoroutineStep<I,O>

Parameters:

fPreviousExecution - The future of the previous code execution

rNextStep - The next step to execute or NULL for none

rContinuation - The continuation of the execution

execute

protected O execute(I rInput,
                    Continuation<?> rContinuation)

This method must be implemented by subclasses to provide the actual functionality of this step.

Specified by:

execute in class CoroutineStep<I,O>

Parameters:

rInput - The input value

rContinuation - The continuation of the execution

Returns:

The result of the execution