public final class Predicates extends Object
Predicate
, copied from Guava.
The function signatures below are identical to Google's Guava 18.0, except that guava's functional interfaces have been swapped with Java 8's. It is tested against the same test suite as Google Guava to ensure functional compatibility.
Most of the implementation has been replaced with lambdas, which means that the following functionality has been removed: equals(), hashCode(), toString(), GWT, and serialization.
Lambdas don't support these methods, and there isn't much reason why they should, so we removed them in Durian.
Modifier and Type | Method and Description |
---|---|
static <T> Predicate<T> |
alwaysFalse()
Returns a predicate that always evaluates to
false . |
static <T> Predicate<T> |
alwaysTrue()
Returns a predicate that always evaluates to
true . |
static <T> Predicate<T> |
and(Iterable<? extends Predicate<? super T>> components)
Returns a predicate that evaluates to
true if each of its
components evaluates to true . |
static <T> Predicate<T> |
and(Predicate<? super T>... components)
Returns a predicate that evaluates to
true if each of its
components evaluates to true . |
static <T> Predicate<T> |
and(Predicate<? super T> first,
Predicate<? super T> second)
Returns a predicate that evaluates to
true if both of its
components evaluate to true . |
static Predicate<Class<?>> |
assignableFrom(Class<?> clazz)
Returns a predicate that evaluates to
true if the class being
tested is assignable from the given class. |
static <A,B> Predicate<A> |
compose(Predicate<B> predicate,
Function<A,? extends B> function)
Returns the composition of a function and a predicate.
|
static Predicate<CharSequence> |
contains(Pattern pattern)
Returns a predicate that evaluates to
true if the
CharSequence being tested contains any match for the given
regular expression pattern. |
static Predicate<CharSequence> |
containsPattern(String pattern)
Returns a predicate that evaluates to
true if the
CharSequence being tested contains any match for the given
regular expression pattern. |
static <T> Predicate<T> |
equalTo(T target)
Returns a predicate that evaluates to
true if the object being
tested equals() the given target or both are null. |
static <T> Predicate<T> |
in(Collection<? extends T> target)
Returns a predicate that evaluates to
true if the object reference
being tested is a member of the given collection. |
static Predicate<Object> |
instanceOf(Class<?> clazz)
Returns a predicate that evaluates to
true if the object being
tested is an instance of the given class. |
static <T> Predicate<T> |
isNull()
Returns a predicate that evaluates to
true if the object reference
being tested is null. |
static <T> Predicate<T> |
not(Predicate<T> predicate)
Returns a predicate that evaluates to
true if the given predicate
evaluates to false . |
static <T> Predicate<T> |
notNull()
Returns a predicate that evaluates to
true if the object reference
being tested is not null. |
static <T> Predicate<T> |
or(Iterable<? extends Predicate<? super T>> components)
Returns a predicate that evaluates to
true if any one of its
components evaluates to true . |
static <T> Predicate<T> |
or(Predicate<? super T>... components)
Returns a predicate that evaluates to
true if any one of its
components evaluates to true . |
static <T> Predicate<T> |
or(Predicate<? super T> first,
Predicate<? super T> second)
Returns a predicate that evaluates to
true if either of its
components evaluates to true . |
public static <T> Predicate<T> alwaysTrue()
true
.public static <T> Predicate<T> alwaysFalse()
false
.public static <T> Predicate<T> isNull()
true
if the object reference
being tested is null.public static <T> Predicate<T> notNull()
true
if the object reference
being tested is not null.public static <T> Predicate<T> not(Predicate<T> predicate)
true
if the given predicate
evaluates to false
.public static <T> Predicate<T> and(Iterable<? extends Predicate<? super T>> components)
true
if each of its
components evaluates to true
. The components are evaluated in
order, and evaluation will be "short-circuited" as soon as a false
predicate is found. It defensively copies the iterable passed in, so future
changes to it won't alter the behavior of this predicate. If components
is empty, the returned predicate will always evaluate to true
.@SafeVarargs public static <T> Predicate<T> and(Predicate<? super T>... components)
true
if each of its
components evaluates to true
. The components are evaluated in
order, and evaluation will be "short-circuited" as soon as a false
predicate is found. It defensively copies the array passed in, so future
changes to it won't alter the behavior of this predicate. If components
is empty, the returned predicate will always evaluate to true
.public static <T> Predicate<T> and(Predicate<? super T> first, Predicate<? super T> second)
true
if both of its
components evaluate to true
. The components are evaluated in
order, and evaluation will be "short-circuited" as soon as a false
predicate is found.public static <T> Predicate<T> or(Iterable<? extends Predicate<? super T>> components)
true
if any one of its
components evaluates to true
. The components are evaluated in
order, and evaluation will be "short-circuited" as soon as a
true predicate is found. It defensively copies the iterable passed in, so
future changes to it won't alter the behavior of this predicate. If components
is empty, the returned predicate will always evaluate to false
.@SafeVarargs public static <T> Predicate<T> or(Predicate<? super T>... components)
true
if any one of its
components evaluates to true
. The components are evaluated in
order, and evaluation will be "short-circuited" as soon as a
true predicate is found. It defensively copies the array passed in, so
future changes to it won't alter the behavior of this predicate. If components
is empty, the returned predicate will always evaluate to false
.public static <T> Predicate<T> or(Predicate<? super T> first, Predicate<? super T> second)
true
if either of its
components evaluates to true
. The components are evaluated in
order, and evaluation will be "short-circuited" as soon as a
true predicate is found.public static <T> Predicate<T> equalTo(@Nullable T target)
true
if the object being
tested equals()
the given target or both are null.public static Predicate<Object> instanceOf(Class<?> clazz)
true
if the object being
tested is an instance of the given class. If the object being tested
is null
this predicate evaluates to false
.public static Predicate<Class<?>> assignableFrom(Class<?> clazz)
true
if the class being
tested is assignable from the given class. The returned predicate
does not allow null inputs.public static <T> Predicate<T> in(Collection<? extends T> target)
true
if the object reference
being tested is a member of the given collection. It does not defensively
copy the collection passed in, so future changes to it will alter the
behavior of the predicate.
This method can technically accept any Collection<?>
, but using
a typed collection helps prevent bugs. This approach doesn't block any
potential users since it is always possible to use Predicates.<Object>in()
.
target
- the collection that may contain the function inputpublic static <A,B> Predicate<A> compose(Predicate<B> predicate, Function<A,? extends B> function)
x
,
the generated predicate returns predicate(function(x))
.public static Predicate<CharSequence> containsPattern(String pattern)
true
if the
CharSequence
being tested contains any match for the given
regular expression pattern. The test used is equivalent to
Pattern.compile(pattern).matcher(arg).find()
PatternSyntaxException
- if the pattern is invalidpublic static Predicate<CharSequence> contains(Pattern pattern)
true
if the
CharSequence
being tested contains any match for the given
regular expression pattern. The test used is equivalent to
pattern.matcher(arg).find()