Type Parameters:

T - type to extract from

E - enum type

All Superinterfaces:

Comparator<T>, Expression<T>, Function<T,E>, HasCompare<T>, HasCompose<T>, HasHash<T>, HasMapIfPresent<T,UnaryOperator<E>,ToEnumNullable<T,E>>, HasMapToDoubleIfPresent<T,ToDoubleFunction<E>>, ToNullable<T,E,ToEnum<T,E>>
```
public interface ToEnumNullable<T,E extends Enum<E>>
extends Expression<T>, ToNullable<T,E,ToEnum<T,E>>, HasMapToDoubleIfPresent<T,ToDoubleFunction<E>>, HasMapIfPresent<T,UnaryOperator<E>,ToEnumNullable<T,E>>, HasHash<T>, HasCompare<T>, HasCompose<T>
```
Expression that given an entity returns an enum value, or null. The expression also knows about the enum class and can therefore not be implemented as a lambda like the other expressions in this module.

Since:

3.1.0

Author:

Emil Forslund

See Also:

Function

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`default ToStringNullable<T>`	`asName()`	Returns an alternative expression that represents the `Enum.name()` of the enum that would otherwise have been returned by this expression.
`default ToIntNullable<T>`	`asOrdinal()`	Returns an alternative expression that represents the `Enum.ordinal()` of the enum that would otherwise have been returned by this expression.
`default int`	`compare(T first, T second)`
`default <V> ToEnumNullable<V,E>`	`compose(Function<? super V,? extends T> before)`	Returns a composed expression that first applies the `before` function to its input, and then applies this function to the result.
`Class<E>`	`enumClass()`	Returns the `class` of the enum that this expression returns.
`default ExpressionType`	`expressionType()`	Returns the expression type of this expression.
`default long`	`hash(T object)`	Hash the specified object into a 64-bit hash.
`default ToEnumNullable<T,E>`	`mapIfPresent(UnaryOperator<E> mapper)`	Returns an expression for the value of this expression mapped using the specified mapping function.
`default ToDoubleNullable<T>`	`mapToDoubleIfPresent(ToDoubleFunction<E> mapper)`	Maps the result of this expression into a `double` by passing it to the specified `mapper`, producing a new expression that implements `ToDouble`.
`static <T,E extends Enum<E>> ToEnumNullable<T,E>`	`of(Class<E> enumClass, Function<T,E> lambda)`	Returns a typed `ToEnumNullable<T>` using the provided `lambda`.
`default ToEnum<T,E>`	`orElse(E value)`	Returns an equivalent expression as this, except that it will return the `value` if given an argument that would cause this expression to return `null`.
`default ToEnum<T,E>`	`orElseGet(ToEnum<T,E> getter)`	Returns an equivalent expression as this, except that it will return the `getter` expression if given an argument that would cause this expression to return `null`.
`default ToEnum<T,E>`	`orThrow()`	Returns an equivalent expression as this, except that it will throw a `NullPointerException` if given an argument that would cause this expression to return `null`.

Methods inherited from interface java.util.Comparator
equals, reversed, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Methods inherited from interface java.util.function.Function
andThen, apply

Methods inherited from interface com.speedment.runtime.compute.trait.ToNullable
isNotNull, isNotNull, isNull, isNull

- Method Detail
  - of
```
static <T,E extends Enum<E>> ToEnumNullable<T,E> of(Class<E> enumClass,
                                                                Function<T,E> lambda)
```
    Returns a typed ToEnumNullable<T> using the provided lambda.
    
    Type Parameters:
    
    T - type to extract from
    
    E - enum type
    
    Parameters:
    
    lambda - to convert
    
    enumClass - class for the enum
    
    Returns:
    
    a typed ToEnumNullable<T> using the provided lambda
    
    Throws:
    
    NullPointerException - if the provided lambda is null
  - enumClass
```
Class<E> enumClass()
```
    Returns the class of the enum that this expression returns.
    
    Returns:
    
    the enum class
  - expressionType
```
default ExpressionType expressionType()
```
    Description copied from interface: Expression
    
    Returns the expression type of this expression. It should be safe to cast this instance into the corresponding interface.
    
    Specified by:
    
    expressionType in interface Expression<T>
    
    Returns:
    
    the expression type
  - asOrdinal
```
default ToIntNullable<T> asOrdinal()
```
    Returns an alternative expression that represents the Enum.ordinal() of the enum that would otherwise have been returned by this expression.
    If this expression would have returned null, then the new expression will also evaluate to null.
    
    Returns:
    
    the ordinal expression
  - asName
```
default ToStringNullable<T> asName()
```
    Returns an alternative expression that represents the Enum.name() of the enum that would otherwise have been returned by this expression.
    If this expression would have returned null, then the new expression will also evaluate to null.
    
    Returns:
    
    the name expression
  - orThrow
```
default ToEnum<T,E> orThrow()
```
    Description copied from interface: ToNullable
    
    Returns an equivalent expression as this, except that it will throw a NullPointerException if given an argument that would cause this expression to return null.
    
    Specified by:
    
    orThrow in interface ToNullable<T,E extends Enum<E>,ToEnum<T,E extends Enum<E>>>
    
    Returns:
    
    the expression if present
  - orElseGet
```
default ToEnum<T,E> orElseGet(ToEnum<T,E> getter)
```
    Description copied from interface: ToNullable
    
    Returns an equivalent expression as this, except that it will return the getter expression if given an argument that would cause this expression to return null.
    
    Specified by:
    
    orElseGet in interface ToNullable<T,E extends Enum<E>,ToEnum<T,E extends Enum<E>>>
    
    Parameters:
    
    getter - to apply if null
    
    Returns:
    
    the expression if present, otherwise return getter
  - orElse
```
default ToEnum<T,E> orElse(E value)
```
    Description copied from interface: ToNullable
    
    Returns an equivalent expression as this, except that it will return the value if given an argument that would cause this expression to return null.
    
    Specified by:
    
    orElse in interface ToNullable<T,E extends Enum<E>,ToEnum<T,E extends Enum<E>>>
    
    Parameters:
    
    value - value to use if null
    
    Returns:
    
    the expression if present, otherwise return value
  - mapToDoubleIfPresent
```
default ToDoubleNullable<T> mapToDoubleIfPresent(ToDoubleFunction<E> mapper)
```
    Description copied from interface: HasMapToDoubleIfPresent
    
    Maps the result of this expression into a double by passing it to the specified mapper, producing a new expression that implements ToDouble. If this expression would have evaluated to null, then the new expression will as well.
    
    Specified by:
    
    mapToDoubleIfPresent in interface HasMapToDoubleIfPresent<T,E extends Enum<E>>
    
    Parameters:
    
    mapper - the mapper to use on the result of this expression
    
    Returns:
    
    the new mapped expression
  - mapIfPresent
```
default ToEnumNullable<T,E> mapIfPresent(UnaryOperator<E> mapper)
```
    Description copied from interface: HasMapIfPresent
    
    Returns an expression for the value of this expression mapped using the specified mapping function. The input type remains the same.
    
    Specified by:
    
    mapIfPresent in interface HasMapIfPresent<T,UnaryOperator<E extends Enum<E>>,ToEnumNullable<T,E extends Enum<E>>>
    
    Parameters:
    
    mapper - the mapping function
    
    Returns:
    
    the mapped expression
  - hash
```
default long hash(T object)
```
    Description copied from interface: HasHash
    
    Hash the specified object into a 64-bit hash. If two equal objects are hashed, they must always result in the same hash. However, objects that are not equal may also result in the same hash.
    
    Specified by:
    
    hash in interface HasHash<T>
    
    Parameters:
    
    object - the object to hash
    
    Returns:
    
    the 64-bit hashcode
  - compare
```
default int compare(T first,
                    T second)
```
    Specified by:
    
    compare in interface Comparator<T>
    
    Specified by:
    
    compare in interface HasCompare<T>
  - compose
```
default <V> ToEnumNullable<V,E> compose(Function<? super V,? extends T> before)
```
    Description copied from interface: HasCompose
    
    Returns a composed expression that first applies the before function to its input, and then applies this function to the result. If evaluation of either function throws an exception, it is relayed to the caller of the composed function.
    
    Specified by:
    
    compose in interface Function<T,E extends Enum<E>>
    
    Specified by:
    
    compose in interface HasCompose<T>
    
    Type Parameters:
    
    V - the type of input to the before function, and to the composed expression
    
    Parameters:
    
    before - the function to apply before this function is applied
    
    Returns:
    
    a composed function that first applies the before function and then applies this function

Interface ToEnumNullable<T,​E extends Enum<E>>

Method Summary

Methods inherited from interface java.util.Comparator

Methods inherited from interface java.util.function.Function

Methods inherited from interface com.speedment.runtime.compute.trait.ToNullable

Method Detail

of

enumClass

expressionType

asOrdinal

asName

orThrow

orElseGet

orElse

mapToDoubleIfPresent

mapIfPresent

hash

compare

compose

Interface ToEnumNullable<T,E extends Enum<E>>