com.google.common.collect

Class DiscreteDomain<C extends java.lang.Comparable>

java.lang.Object

com.google.common.collect.DiscreteDomain<C>

@GwtCompatible
 @Beta
public abstract class DiscreteDomain<C extends java.lang.Comparable>
extends java.lang.Object

A descriptor for a discrete Comparable domain such as all Integer instances. A discrete domain is one that supports the three basic operations: next(C), previous(C) and distance(C, C), according to their specifications. The methods minValue() and maxValue() should also be overridden for bounded types.

A discrete domain always represents the entire set of values of its type; it cannot represent partial domains such as "prime integers" or "strings of length 5."

See the Guava User Guide section on DiscreteDomain.

Since:

10.0

Method Summary

Modifier and Type	Method and Description
abstract long	distance(C start, C end) Returns a signed value indicating how many nested invocations of next(C) (if positive) or previous(C) (if negative) are needed to reach end starting from start.
static DiscreteDomain<java.lang.Integer>	integers() Returns the discrete domain for values of type Integer.
static DiscreteDomain<java.lang.Long>	longs() Returns the discrete domain for values of type Long.
C	maxValue() Returns the maximum value of type C, if it has one.
C	minValue() Returns the minimum value of type C, if it has one.
abstract C	next(C value) Returns the unique least value of type C that is greater than value, or null if none exists.
abstract C	previous(C value) Returns the unique greatest value of type C that is less than value, or null if none exists.

Methods inherited from class java.lang.Object

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

Method Detail

integers

public static DiscreteDomain<java.lang.Integer> integers()

Returns the discrete domain for values of type Integer.

Since:

14.0 (since 10.0 as DiscreteDomains.integers())

longs

public static DiscreteDomain<java.lang.Long> longs()

Returns the discrete domain for values of type Long.

Since:

14.0 (since 10.0 as DiscreteDomains.longs())

next

public abstract C next(C value)

Returns the unique least value of type C that is greater than value, or null if none exists. Inverse operation to previous(C).

Parameters:

value - any value of type C

Returns:

the least value greater than value, or null if value is maxValue()

previous

public abstract C previous(C value)

Returns the unique greatest value of type C that is less than value, or null if none exists. Inverse operation to next(C).

Parameters:

value - any value of type C

Returns:

the greatest value less than value, or null if value is minValue()

distance

public abstract long distance(C start,
                              C end)

Returns a signed value indicating how many nested invocations of next(C) (if positive) or previous(C) (if negative) are needed to reach end starting from start. For example, if end = next(next(next(start))), then distance(start, end) == 3 and distance(end, start) == -3. As well, distance(a, a) is always zero.

Note that this function is necessarily well-defined for any discrete type.

Returns:

the distance as described above, or Long.MIN_VALUE or Long.MAX_VALUE if the distance is too small or too large, respectively.

minValue

public C minValue()

Returns the minimum value of type C, if it has one. The minimum value is the unique value for which Comparable.compareTo(Object) never returns a positive value for any input of type C.

The default implementation throws NoSuchElementException.

Returns:

the minimum value of type C; never null

Throws:

java.util.NoSuchElementException - if the type has no (practical) minimum value; for example, BigInteger

maxValue

public C maxValue()

Returns the maximum value of type C, if it has one. The maximum value is the unique value for which Comparable.compareTo(Object) never returns a negative value for any input of type C.

The default implementation throws NoSuchElementException.

Returns:

the maximum value of type C; never null

Throws:

java.util.NoSuchElementException - if the type has no (practical) maximum value; for example, BigInteger