Class IntegerSequence.Incrementor

java.lang.Object

org.apache.commons.math3.util.IntegerSequence.Incrementor

All Implemented Interfaces:

Iterator<Integer>

Enclosing class:

IntegerSequence

public static class IntegerSequence.Incrementor
extends Object
implements Iterator<Integer>

Utility that increments a counter until a maximum is reached, at which point, the instance will by default throw a MaxCountExceededException. However, the user is able to override this behaviour by defining a custom callback, in order to e.g. select which exception must be thrown.

Since:

3.6

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	IntegerSequence.Incrementor.MaxCountExceededCallback	Defines a method to be called at counter exhaustion.

Method Summary

Modifier and Type	Method	Description
boolean	canIncrement()	Checks whether incrementing the counter nTimes is allowed.
boolean	canIncrement(int nTimes)	Checks whether incrementing the counter several times is allowed.
static IntegerSequence.Incrementor	create()	Factory method that creates a default instance.
int	getCount()	Gets the current count.
int	getMaximalCount()	Gets the upper limit of the counter.
boolean	hasNext()
void	increment()	Adds the increment value to the current iteration count.
void	increment(int nTimes)	Performs multiple increments.
Integer	next()
void	remove()	Not applicable.
IntegerSequence.Incrementor	withCallback(IntegerSequence.Incrementor.MaxCountExceededCallback cb)	Creates a new instance with a given callback.
IntegerSequence.Incrementor	withIncrement(int step)	Creates a new instance with a given increment.
IntegerSequence.Incrementor	withMaximalCount(int max)	Creates a new instance with a given maximal count.
IntegerSequence.Incrementor	withStart(int start)	Creates a new instance with a given initial value.

Methods inherited from class Object

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

Methods inherited from interface Iterator

forEachRemaining

Method Details

create

public static IntegerSequence.Incrementor create()

Factory method that creates a default instance. The initial and maximal values are set to 0. For the new instance to be useful, the maximal count must be set by calling withMaximalCount.

Returns:

an new instance.

withStart

public IntegerSequence.Incrementor withStart(int start)

Creates a new instance with a given initial value. The counter is reset to the initial value.

Parameters:

start - Initial value of the counter.

Returns:

a new instance.

withMaximalCount

public IntegerSequence.Incrementor withMaximalCount(int max)

Creates a new instance with a given maximal count. The counter is reset to the initial value.

Parameters:

max - Maximal count.

Returns:

a new instance.

withIncrement

public IntegerSequence.Incrementor withIncrement(int step)

Creates a new instance with a given increment. The counter is reset to the initial value.

Parameters:

step - Increment.

Returns:

a new instance.

withCallback

public IntegerSequence.Incrementor withCallback(IntegerSequence.Incrementor.MaxCountExceededCallback cb)

Creates a new instance with a given callback. The counter is reset to the initial value.

Parameters:

cb - Callback to be called at counter exhaustion.

Returns:

a new instance.

getMaximalCount

public int getMaximalCount()

Gets the upper limit of the counter.

Returns:

the counter upper limit.

getCount

public int getCount()

Gets the current count.

Returns:

the current count.

canIncrement

public boolean canIncrement()

Checks whether incrementing the counter nTimes is allowed.

Returns:

false if calling increment() will trigger a MaxCountExceededException, true otherwise.

canIncrement

public boolean canIncrement(int nTimes)

Checks whether incrementing the counter several times is allowed.

Parameters:

nTimes - Number of increments.

Returns:

false if calling increment(nTimes) would call the callback true otherwise.

increment

public void increment(int nTimes)
               throws MaxCountExceededException

Performs multiple increments.

Parameters:

nTimes - Number of increments.

Throws:

MaxCountExceededException - at counter exhaustion.

NotStrictlyPositiveException - if nTimes <= 0.

See Also:

• increment()

increment

public void increment()
               throws MaxCountExceededException

Adds the increment value to the current iteration count. At counter exhaustion, this method will call the trigger method of the callback object passed to the withCallback(MaxCountExceededCallback) method. If not explicitly set, a default callback is used that will throw a MaxCountExceededException.

Throws:

MaxCountExceededException - at counter exhaustion, unless a custom callback has been set.

See Also:

• increment(int)

hasNext

public boolean hasNext()

Specified by:

hasNext in interface Iterator<Integer>

next

public Integer next()

Specified by:

next in interface Iterator<Integer>

remove

public void remove()

Not applicable.

Specified by:

remove in interface Iterator<Integer>

Throws:

MathUnsupportedOperationException