uk.kludje.fn.function

Interface UFunction<T,R>

All Superinterfaces:

java.util.function.Function<T,R>

Functional Interface:

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

@FunctionalInterface
 @Generated(value="uk.kludje.annotation.processor.UncheckedFunctionalInterfaceProcessor")
public interface UFunction<T,R>
extends java.util.function.Function<T,R>

TLDR; IMPLEMENT R $apply(T arg0) throws Throwable USING A LAMBDA; INVOKE R apply(T arg0).

A functional interface for handling checked exceptions. See parent type for interface intent.

R apply(T arg0) invokes R $apply(T arg0) and throws anything thrown by R $apply(T arg0).

General example using java.lang.Runnable that reduces 11 lines to a single line. Call someMethodThatThrowsException in throwsNothing:

 public void someMethodThatThrowsException() throws IOException {
   // I/O functionality
 }

 public void throwsNothing(Runnable r) {
   r.run();
 }
 

Before:

 public void yourMethod() throws IOException {
   try {
     throwsNothing(() -> {
       try {
         someMethodThatThrowsException();
       } catch (IOException e) {
         throw new SomeWrapperException(e);
       }
     });
   } catch(SomeWrapperException w) {
     throw (IOException) w.getCause();
   }
 }
 

After:

 public void yourMethod() throws IOException {
   throwsNothing((URunnable) this::someMethodThatThrowsException);
 }
 

Method public static <T, R> UFunction<T, R> asUFunction(UFunction<T, R> t) provides a convenience method for manufacturing types as an alternative to casting.

Method Summary

Modifier and Type	Method and Description
R	$apply(T arg0)
default R	apply(T arg0)
static <T,R> UFunction<T,R>	asUFunction(UFunction<T,R> t)

Methods inherited from interface java.util.function.Function

andThen, compose, identity

Method Detail

apply

default R apply(T arg0)

Specified by:

apply in interface java.util.function.Function<T,R>

$apply

R $apply(T arg0)
  throws java.lang.Throwable

Throws:

java.lang.Throwable

asUFunction

static <T,R> UFunction<T,R> asUFunction(UFunction<T,R> t)