Package org.openjdk.jmc.common.util

Class PredicateToolkit

java.lang.Object

org.openjdk.jmc.common.util.PredicateToolkit

public class PredicateToolkit
extends Object

Toolkit used to create instances of Predicate matching various criteria.

Constructor Summary

Constructors

Constructor	Description
PredicateToolkit()

Method Summary

Modifier and Type	Method	Description
static <T> Predicate<T>	and(Collection<Predicate<T>> predicates)	Combine a collection of predicates using an AND operation.
static <T,M extends Comparable<? super M>> Predicate<T>	centerContained(IMemberAccessor<? extends IRange<M>,T> rangeAccessor, IRange<M> limit)	Return a predicate based on limit according to RangeMatchPolicy.CENTER_CONTAINED_IN_RIGHT_OPEN.
static <T> Predicate<T>	contains(IMemberAccessor<? extends String,T> valueAccessor, String substring)	Create a predicate that checks if a string value contains a specified substring.
static <T> Predicate<T>	equals(IMemberAccessor<?,T> valueAccessor, Object item)	Create a predicate that checks if a value is equal to a specified object.
static <T> Predicate<T>	falsePredicate()
static Pattern	getValidPattern(String regexp)	Compile a regular expression into a pattern if possible.
static <T> Predicate<T>	is(T item)	Create a predicate that checks if a value is a specified object.
static boolean	isFalseGuaranteed(Predicate<?> p)	Test if a predicate is guaranteed to always test to false.
static boolean	isTrueGuaranteed(Predicate<?> p)	Test if a predicate is guaranteed to always test to true.
static <T,M> Predicate<T>	less(IMemberAccessor<? extends M,T> valueAccessor, Comparable<? super M> limit)	Create a predicate that compares values to a limit.
static <T,M> Predicate<T>	less(IMemberAccessor<? extends M,T> valueAccessor, Comparable<? super M> limit, boolean orEqual)	Create a predicate that compares values to a limit.
static <T,M> Predicate<T>	lessOrEqual(IMemberAccessor<? extends M,T> valueAccessor, Comparable<? super M> limit)	Create a predicate that compares values to a limit.
static <T> Predicate<T>	matches(IMemberAccessor<? extends String,T> valueAccessor, String regexp)	Create a predicate that checks if a string value matches a regular expression.
static <T,M> Predicate<T>	memberOf(IMemberAccessor<? extends M,T> valueAccessor, Set<? extends M> items)	Create a predicate that checks if a value is included in a specified set.
static <T,M> Predicate<T>	more(IMemberAccessor<? extends M,T> valueAccessor, Comparable<? super M> limit)	Create a predicate that compares values to a limit.
static <T,M> Predicate<T>	more(IMemberAccessor<? extends M,T> valueAccessor, Comparable<? super M> limit, boolean orEqual)	Create a predicate that compares values to a limit.
static <T,M> Predicate<T>	moreOrEqual(IMemberAccessor<? extends M,T> valueAccessor, Comparable<? super M> limit)	Create a predicate that compares values to a limit.
static <T> Predicate<T>	not(Predicate<T> predicate)	Invert a predicate.
static <T> Predicate<T>	notEquals(IMemberAccessor<?,T> valueAccessor, Object item)	Create a predicate that checks if a value is not equal to a specified object.
static <T> Predicate<T>	or(Collection<Predicate<T>> predicates)	Combine a collection of predicates using an OR operation.
static <T,M extends Comparable<? super M>> Predicate<T>	rangeContained(IMemberAccessor<? extends IRange<M>,T> rangeAccessor, IRange<M> limit)	Return a predicate based on limit according to RangeMatchPolicy.CONTAINED_IN_CLOSED.
static <T,M extends Comparable<? super M>> Predicate<T>	rangeIntersects(IMemberAccessor<? extends IRange<M>,T> rangeAccessor, IRange<M> limit)	Return a predicate based on limit according to RangeMatchPolicy.CLOSED_INTERSECTS_WITH_CLOSED.
static <T> Predicate<T>	truePredicate()

Methods inherited from class java.lang.Object

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

Constructor Detail

PredicateToolkit

public PredicateToolkit()

Method Detail

truePredicate

public static <T> Predicate<T> truePredicate()

Returns:

a predicate that always will test to true

falsePredicate

public static <T> Predicate<T> falsePredicate()

Returns:

a predicate that always will test to false

isTrueGuaranteed

public static boolean isTrueGuaranteed(Predicate<?> p)

Test if a predicate is guaranteed to always test to true. Note that if this method returns false, then it only means that it is unknown what the predicate will return.

Parameters:

p - a predicate to test

Returns:

true if the predicate is guaranteed to test to true

isFalseGuaranteed

public static boolean isFalseGuaranteed(Predicate<?> p)

Test if a predicate is guaranteed to always test to false. Note that if this method returns false, then it only means that it is unknown what the predicate will return.

Parameters:

p - a predicate to test

Returns:

true if the predicate is guaranteed to test to false

and

public static <T> Predicate<T> and(Collection<Predicate<T>> predicates)

Combine a collection of predicates using an AND operation.

Parameters:

predicates - input predicates

Returns:

a predicate that tests to true if all input predicates test to true

or

public static <T> Predicate<T> or(Collection<Predicate<T>> predicates)

Combine a collection of predicates using an OR operation.

Parameters:

predicates - input predicates

Returns:

a predicate that tests to true if at least one of the input predicates test to true

not

public static <T> Predicate<T> not(Predicate<T> predicate)

Invert a predicate.

Parameters:

predicate - predicate to invert

Returns:

a predicate that tests to true if the input predicate tests to false and vice versa

less

public static <T,M> Predicate<T> less(IMemberAccessor<? extends M,T> valueAccessor,
                                            Comparable<? super M> limit,
                                            boolean orEqual)

Create a predicate that compares values to a limit.

The predicate takes an input object as argument but the value that is checked is extracted from the input object using a member accessor.

Type Parameters:

T - type of objects passed into the predicate

M - type of the value that is compared

Parameters:

valueAccessor - accessor used to get the value to check from the input type

limit - value to compare against

orEqual - if true, test values that are equal to the limit to true

Returns:

a predicate that tests to true if the value to check is less than, or optionally equal to, the limit value

less

public static <T,M> Predicate<T> less(IMemberAccessor<? extends M,T> valueAccessor,
                                            Comparable<? super M> limit)

Create a predicate that compares values to a limit.

The predicate takes an input object as argument but the value that is checked is extracted from the input object using a member accessor.

Type Parameters:

T - type of objects passed into the predicate

M - type of the value that is compared

Parameters:

valueAccessor - accessor used to get the value to check from the input type

limit - value to compare against

Returns:

a predicate that tests to true if the value to check is strictly less than the limit value

lessOrEqual

public static <T,M> Predicate<T> lessOrEqual(IMemberAccessor<? extends M,T> valueAccessor,
                                                   Comparable<? super M> limit)

Create a predicate that compares values to a limit.

The predicate takes an input object as argument but the value that is checked is extracted from the input object using a member accessor.

Type Parameters:

T - type of objects passed into the predicate

M - type of the value that is compared

Parameters:

valueAccessor - accessor used to get the value to check from the input type

limit - value to compare against

Returns:

a predicate that tests to true if the value to check is less than or equal to the limit value

more

public static <T,M> Predicate<T> more(IMemberAccessor<? extends M,T> valueAccessor,
                                            Comparable<? super M> limit,
                                            boolean orEqual)

Create a predicate that compares values to a limit.

The predicate takes an input object as argument but the value that is checked is extracted from the input object using a member accessor.

Type Parameters:

T - type of objects passed into the predicate

M - type of the value that is compared

Parameters:

valueAccessor - accessor used to get the value to check from the input type

limit - value to compare against

orEqual - if true, test values that are equal to the limit to true

Returns:

a predicate that tests to true if the value to check is greater than, or optionally equal to, the limit value

more

public static <T,M> Predicate<T> more(IMemberAccessor<? extends M,T> valueAccessor,
                                            Comparable<? super M> limit)

Create a predicate that compares values to a limit.

The predicate takes an input object as argument but the value that is checked is extracted from the input object using a member accessor.

Type Parameters:

T - type of objects passed into the predicate

M - type of the value that is compared

Parameters:

valueAccessor - accessor used to get the value to check from the input type

limit - value to compare against

Returns:

a predicate that tests to true if the value to check is strictly greater than the limit value

moreOrEqual

public static <T,M> Predicate<T> moreOrEqual(IMemberAccessor<? extends M,T> valueAccessor,
                                                   Comparable<? super M> limit)

Create a predicate that compares values to a limit.

The predicate takes an input object as argument but the value that is checked is extracted from the input object using a member accessor.

Type Parameters:

T - type of objects passed into the predicate

M - type of the value that is compared

Parameters:

valueAccessor - accessor used to get the value to check from the input type

limit - value to compare against

Returns:

a predicate that tests to true if the value to check is greater than or equal to the limit value

rangeIntersects

public static <T,M extends Comparable<? super M>> Predicate<T> rangeIntersects(IMemberAccessor<? extends IRange<M>,T> rangeAccessor,
                                                                                     IRange<M> limit)

Return a predicate based on limit according to RangeMatchPolicy.CLOSED_INTERSECTS_WITH_CLOSED.

The predicate takes an input object as argument but the range that is checked is extracted from the input object using a member accessor.

Type Parameters:

T - type of objects passed into the predicate

M - type of the range value that is compared

Parameters:

rangeAccessor - accessor used to get the range value to check from the input type

limit - range value to compare against

Returns:

a predicate that tests to true if the range value to check intersects with the limit range

rangeContained

public static <T,M extends Comparable<? super M>> Predicate<T> rangeContained(IMemberAccessor<? extends IRange<M>,T> rangeAccessor,
                                                                                    IRange<M> limit)

Return a predicate based on limit according to RangeMatchPolicy.CONTAINED_IN_CLOSED.

The predicate takes an input object as argument but the range that is checked is extracted from the input object using a member accessor.

Type Parameters:

T - type of objects passed into the predicate

M - type of the range value that is compared

Parameters:

rangeAccessor - accessor used to get the range value to check from the input type

limit - range value to compare against

Returns:

a predicate that tests to true if the range value to check is contained in the limit range

centerContained

public static <T,M extends Comparable<? super M>> Predicate<T> centerContained(IMemberAccessor<? extends IRange<M>,T> rangeAccessor,
                                                                                     IRange<M> limit)

Return a predicate based on limit according to RangeMatchPolicy.CENTER_CONTAINED_IN_RIGHT_OPEN.

The predicate takes an input object as argument but the range that is checked is extracted from the input object using a member accessor.

Type Parameters:

T - type of objects passed into the predicate

M - type of the range value that is compared

Parameters:

rangeAccessor - accessor used to get the range value to check from the input type

limit - range value to compare against

Returns:

a predicate that tests to true if the center point of the range value to check is contained in the limit range

equals

public static <T> Predicate<T> equals(IMemberAccessor<?,T> valueAccessor,
                                      Object item)

Create a predicate that checks if a value is equal to a specified object.

The predicate takes an input object as argument but the value that is checked is extracted from the input object using a member accessor.

Type Parameters:

T - type of objects passed into the predicate

Parameters:

valueAccessor - accessor used to get the value to check from the input type

item - object to compare against

Returns:

a predicate that tests to true if the value to check is equal to the specified object

notEquals

public static <T> Predicate<T> notEquals(IMemberAccessor<?,T> valueAccessor,
                                         Object item)

Create a predicate that checks if a value is not equal to a specified object.

The predicate takes an input object as argument but the value that is checked is extracted from the input object using a member accessor.

Type Parameters:

T - type of objects passed into the predicate

Parameters:

valueAccessor - accessor used to get the value to check from the input type

item - object to compare against

Returns:

a predicate that tests to true if the value to check is not equal to the specified object

is

public static <T> Predicate<T> is(T item)

Create a predicate that checks if a value is a specified object. This check is performed using object identity.

The predicate takes an input object as argument but the value that is checked is extracted from the input object using a member accessor.

Type Parameters:

T - type of objects passed into the predicate

Parameters:

item - object to compare against

Returns:

a predicate that tests to true if the value to check is the specified object

memberOf

public static <T,M> Predicate<T> memberOf(IMemberAccessor<? extends M,T> valueAccessor,
                                                Set<? extends M> items)

Create a predicate that checks if a value is included in a specified set.

The predicate takes an input object as argument but the value that is checked is extracted from the input object using a member accessor.

Type Parameters:

T - type of objects passed into the predicate

M - type of the range value that is compared

Parameters:

valueAccessor - accessor used to get the value to check from the input type

items - set of objects to compare against

Returns:

a predicate that tests to true if the object to check is included in the specified set

matches

public static <T> Predicate<T> matches(IMemberAccessor<? extends String,T> valueAccessor,
                                       String regexp)

Create a predicate that checks if a string value matches a regular expression.

The predicate takes an input object as argument but the value that is checked is extracted from the input object using a member accessor.

Type Parameters:

T - type of objects passed into the predicate

Parameters:

valueAccessor - string accessor used to get the value to check from the input type

regexp - the regular expression to match

Returns:

a predicate that tests to true if the string value matches the regular expression

contains

public static <T> Predicate<T> contains(IMemberAccessor<? extends String,T> valueAccessor,
                                        String substring)

Create a predicate that checks if a string value contains a specified substring.

The predicate takes an input object as argument but the value that is checked is extracted from the input object using a member accessor.

Parameters:

valueAccessor - string accessor used to get the value to check from the input type

substring - the substring to look for

Returns:

a predicate that tests to true if the string value contains the substring

getValidPattern

public static Pattern getValidPattern(String regexp)

Compile a regular expression into a pattern if possible. If the expression can't be compiled, return a valid pattern that will give 0 matches (at least for single lines).

Parameters:

regexp - regular expression to compile

Returns:

a valid regular expression pattern instance