Predicate (Gerrit Review Plugin API Documentation)

java.lang.Object
- com.google.gerrit.server.query.Predicate<T>

Type Parameters:
T - type of object the predicate can evaluate in memory.

Direct Known Subclasses:

AndPredicate, IndexedQuery, NotPredicate, OperatorPredicate, OrPredicate
```
public abstract class Predicate<T>
extends java.lang.Object
```
An abstract predicate tree for any form of query.
Implementations should be immutable, such that the meaning of a predicate never changes once constructed. They should ensure their immutable promise by defensively copying any structures which might be modified externally, but was passed into the object's constructor.
However, implementations may retain non-thread-safe caches internally, to speed up evaluation operations within the context of one thread's evaluation of the predicate. As a result, callers should assume predicates are not thread-safe, but that two predicate graphs produce the same results given the same inputs if they are equals(Object).
Predicates should support deep inspection whenever possible, so that generic algorithms can be written to operate against them. Predicates which contain other predicates should override getChildren() to return the list of children nested within the predicate.

Constructor Summary

Constructors
Constructor and Description

Predicate()

Constructors
Constructor and Description
`Predicate()`

Method Summary

Methods
Modifier and Type	Method and Description
`static <T> Predicate<T>`	`and(java.util.Collection<? extends Predicate<T>> that)` Combine the passed predicates into a single AND node.
`static <T> Predicate<T>`	`and(Predicate<T>... that)` Combine the passed predicates into a single AND node.
`static <T> Predicate<T>`	`any()` A predicate that matches any input, always, with no cost.
`Matchable<T>`	`asMatchable()`
`abstract Predicate<T>`	`copy(java.util.Collection<? extends Predicate<T>> children)` Create a copy of this predicate, with new children.
`abstract boolean`	`equals(java.lang.Object other)`
`int`	`estimateCost()`
`Predicate<T>`	`getChild(int i)` Same as `getChildren().get(i)`
`int`	`getChildCount()` Same as `getChildren().size()`
`java.util.List<Predicate<T>>`	`getChildren()` Get the children of this predicate, if any.
`abstract int`	`hashCode()`
`boolean`	`isMatchable()`
`static <T> Predicate<T>`	`not(Predicate<T> that)` Invert the passed node.
`static <T> Predicate<T>`	`or(java.util.Collection<? extends Predicate<T>> that)` Combine the passed predicates into a single OR node.
`static <T> Predicate<T>`	`or(Predicate<T>... that)` Combine the passed predicates into a single OR node.

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail
- Predicate
```
public Predicate()
```

Method Detail

any
```
public static <T> Predicate<T> any()
```
A predicate that matches any input, always, with no cost.

and

@SafeVarargs
public static <T> Predicate<T> and(Predicate<T>... that)

Combine the passed predicates into a single AND node.

and

public static <T> Predicate<T> and(java.util.Collection<? extends Predicate<T>> that)

Combine the passed predicates into a single AND node.

or

@SafeVarargs
public static <T> Predicate<T> or(Predicate<T>... that)

Combine the passed predicates into a single OR node.

or

public static <T> Predicate<T> or(java.util.Collection<? extends Predicate<T>> that)

Combine the passed predicates into a single OR node.

not

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

Invert the passed node.

getChildren
```
public java.util.List<Predicate<T>> getChildren()
```
Get the children of this predicate, if any.

getChildCount
```
public int getChildCount()
```
Same as getChildren().size()

getChild
```
public Predicate<T> getChild(int i)
```
Same as getChildren().get(i)

copy

public abstract Predicate<T> copy(java.util.Collection<? extends Predicate<T>> children)

Create a copy of this predicate, with new children.

isMatchable
```
public boolean isMatchable()
```

asMatchable
```
public Matchable<T> asMatchable()
```

estimateCost
```
public int estimateCost()
```
Returns:
a cost estimate to run this predicate, higher figures cost more.

hashCode
```
public abstract int hashCode()
```
Overrides:

hashCode in class java.lang.Object

equals

public abstract boolean equals(java.lang.Object other)

Overrides:: equals in class java.lang.Object

Class Predicate<T>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Predicate

Method Detail

any

and

and

or

or

not

getChildren

getChildCount

getChild

copy

isMatchable

asMatchable

estimateCost

hashCode

equals