com.github.robtimus.sql.function

Interface SQLFunction<T,R>

Type Parameters:

T - The type of the input to the function.

R - The type of the result of the function.

All Known Subinterfaces:

UnarySQLOperator<T>

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface SQLFunction<T,R>

Represents a function that accepts one argument and produces a result. This is the SQLException throwing equivalent of Function.

Method Summary

Modifier and Type	Method and Description
default <V> SQLFunction<T,V>	andThen(SQLFunction<? super R,? extends V> after) Returns a composed function that first applies this function to its input, and then applies the after function to the result.
R	apply(T t) Applies this function to the given argument.
static <T,R> SQLFunction<T,R>	checked(Function<? super T,? extends R> function) Returns a function that applies the function function to its input, and unwraps any UncheckedSQLException that is thrown by throwing its cause.
default <V> SQLFunction<V,R>	compose(SQLFunction<? super V,? extends T> before) Returns a composed function that first applies the before function to its input, and then applies this function to the result.
static <T> SQLFunction<T,T>	identity() Returns a function that always returns its input argument.
static <T,R> Function<T,R>	unchecked(SQLFunction<? super T,? extends R> function) Returns a function that applies the function function to its input, and wraps any SQLException that is thrown in an UncheckedSQLException.

Method Detail

apply

R apply(T t)
 throws SQLException

Applies this function to the given argument.

Parameters:

t - The function argument.

Returns:

The function result.

Throws:

SQLException - If an SQL error occurs.

compose

default <V> SQLFunction<V,R> compose(SQLFunction<? super V,? extends T> before)

Returns a composed function 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.

Type Parameters:

V - The type of input to the before function, and to the composed function.

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.

Throws:

NullPointerException - If before is null.

See Also:

andThen(SQLFunction)

andThen

default <V> SQLFunction<T,V> andThen(SQLFunction<? super R,? extends V> after)

Returns a composed function that first applies this function to its input, and then applies the after function to the result. If evaluation of either function throws an exception, it is relayed to the caller of the composed function.

Type Parameters:

V - The type of output of the after function, and of the composed function.

Parameters:

after - The function to apply after this function is applied.

Returns:

A composed function that first applies this function and then applies the after function.

Throws:

NullPointerException - If after is null.

See Also:

compose(SQLFunction)

identity

static <T> SQLFunction<T,T> identity()

Returns a function that always returns its input argument.

Type Parameters:

T - The type of the input and output objects to the function.

Returns:

A function that always returns its input argument.

unchecked

static <T,R> Function<T,R> unchecked(SQLFunction<? super T,? extends R> function)

Returns a function that applies the function function to its input, and wraps any SQLException that is thrown in an UncheckedSQLException.

Type Parameters:

T - The type of the input to the function.

R - The type of the result of the function.

Parameters:

function - The function to apply when the returned function is applied.

Returns:

A function that applies the function function to its input, and wraps any SQLException that is thrown in an UncheckedSQLException.

Throws:

NullPointerException - If function is null.

checked

static <T,R> SQLFunction<T,R> checked(Function<? super T,? extends R> function)

Returns a function that applies the function function to its input, and unwraps any UncheckedSQLException that is thrown by throwing its cause.

Type Parameters:

T - The type of the input to the function.

R - The type of the result of the function.

Parameters:

function - The function to apply when the returned function is applied.

Returns:

A function that applies the function function to its input, and unwraps any UncheckedSQLException that is thrown.

Throws:

NullPointerException - If function is null.