Constant (Commons Functor 1.0-SNAPSHOT API)

java.lang.Object
- org.apache.commons.functor.core.Constant<T>

Type Parameters:
T - the returned value type.

All Implemented Interfaces:

Serializable, BinaryFunction<Object,Object,T>, BinaryFunctor<Object,Object>, BinaryPredicate<Object,Object>, Function<T>, Functor, NullaryFunctor, Predicate, UnaryFunction<Object,T>, UnaryFunctor<Object>, UnaryPredicate<Object>
```
public final class Constant<T>
extends Object
implements Function<T>, UnaryFunction<Object,T>, BinaryFunction<Object,Object,T>, Predicate, UnaryPredicate<Object>, BinaryPredicate<Object,Object>, Serializable
```
Evaluates to constant value.
Tests to a constant value, assuming a boolean of Boolean value is supplied. Note that although this class implements Serializable, a given instance will only be truly Serializable if the constant Object is. Attempts to serialize an instance whose value is not Serializable will result in an exception.

Version:

$Revision: 1345136 $ $Date: 2012-06-01 08:47:06 -0400 (Fri, 01 Jun 2012) $

See Also:
Serialized Form

Field Summary

Fields
Modifier and Type Field and Description

static Constant<Boolean> FALSE
Constant for false.

static Constant<Boolean> TRUE
Constant for true.

Fields
Modifier and Type	Field and Description
`static Constant<Boolean>`	`FALSE` Constant for `false`.
`static Constant<Boolean>`	`TRUE` Constant for `true`.

Constructor Summary

Constructors
Constructor and Description

Constant(T value)
Create a new Constant.

Constructors
Constructor and Description
`Constant(T value)` Create a new Constant.

Method Summary

Methods
Modifier and Type	Method and Description
`boolean`	`equals(Constant<?> that)` Learn whether another Constant is equal to this.
`boolean`	`equals(Object that)`
`T`	`evaluate()` Evaluate this function.
`T`	`evaluate(Object obj)` Evaluate this function.
`T`	`evaluate(Object left, Object right)` Evaluate this function.
`static Constant<Boolean>`	`falsePredicate()` Get a `Constant` that always returns `false`.
`int`	`hashCode()`
`static <T> Constant<T>`	`of(T value)` Get a Constant instance for the specified value.
`static Constant<Boolean>`	`predicate(boolean value)` Get a `Constant` that always returns value.
`boolean`	`test()` Evaluate this predicate.
`boolean`	`test(Object obj)` Evaluate this predicate.
`boolean`	`test(Object left, Object right)` Evaluate this predicate.
`String`	`toString()`
`static Constant<Boolean>`	`truePredicate()` Get a `Constant` that always returns `true`.

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

- Field Detail
  - TRUE
```
public static final Constant<Boolean> TRUE
```
    Constant for true.
  - FALSE
```
public static final Constant<Boolean> FALSE
```
    Constant for false.
- Constructor Detail
  - Constant
```
public Constant(T value)
```
    Create a new Constant.
    
    Parameters:
    value - Object
- Method Detail
  - evaluate
```
public T evaluate()
```
    Evaluate this function.
    
    Specified by:
    
    evaluate in interface Function<T>
    
    Returns:
    the T result of this evaluation
  - evaluate
```
public T evaluate(Object obj)
```
    Evaluate this function.
    
    Specified by:
    
    evaluate in interface UnaryFunction<Object,T>
    
    Parameters:
    obj - the A object to evaluate
    
    Returns:
    the T result of this evaluation
  - evaluate
```
public T evaluate(Object left,
         Object right)
```
    Evaluate this function.
    
    Specified by:
    
    evaluate in interface BinaryFunction<Object,Object,T>
    
    Parameters:
    left - the L element of the ordered pair of arguments
    right - the R element of the ordered pair of arguments
    
    Returns:
    the T result of this function for the given arguments
  - test
```
public boolean test()
```
    Evaluate this predicate.
    
    Specified by:
    
    test in interface Predicate
    
    Returns:
    the result of this test
  - test
```
public boolean test(Object obj)
```
    Evaluate this predicate.
    
    Specified by:
    
    test in interface UnaryPredicate<Object>
    
    Parameters:
    obj - the A object to test
    
    Returns:
    the result of this test
  - test
```
public boolean test(Object left,
           Object right)
```
    Evaluate this predicate.
    
    Specified by:
    
    test in interface BinaryPredicate<Object,Object>
    
    Parameters:
    left - the L element of the ordered pair of arguments
    right - the R element of the ordered pair of arguments
    
    Returns:
    the result of this test for the given arguments
  - equals
```
public boolean equals(Object that)
```
    Overrides:
    
    equals in class Object
  - equals
```
public boolean equals(Constant<?> that)
```
    Learn whether another Constant is equal to this.
    
    Parameters:
    that - Constant to test
    
    Returns:
    boolean
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - truePredicate
```
public static Constant<Boolean> truePredicate()
```
    Get a Constant that always returns true.
    
    Returns:
    a Constant that always returns true
  - falsePredicate
```
public static Constant<Boolean> falsePredicate()
```
    Get a Constant that always returns false.
    
    Returns:
    a Constant that always returns false
  - predicate
```
public static Constant<Boolean> predicate(boolean value)
```
    Get a Constant that always returns value.
    
    Parameters:
    value - the constant value
    
    Returns:
    a Constant that always returns value
  - of
```
public static <T> Constant<T> of(T value)
```
    Get a Constant instance for the specified value.
    
    Type Parameters:
    T - the constant value
    Parameters:
    value - T
    
    Returns:
    Constant

Class Constant<T>

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

TRUE

FALSE

Constructor Detail

Constant

Method Detail

evaluate

evaluate

evaluate

test

test

test

equals

equals

hashCode

toString

truePredicate

falsePredicate

predicate

of