ch.awae.utils

Class Trampoline

java.lang.Object

ch.awae.utils.Trampoline

public final class Trampoline
extends Object

Utility class for implementing trampoline based primitive recursion.

Whenever a method has a tail call that tail call can be externalised by not returning the result of the call, but instead an object instructing the Trampoline to perform the call to that method and to return the value provided by that function. That function can itself return the instruction to call another method. This allows for iterative execution instead of recursive one preventing StackOverflowErrors.

This class provides all helper methods required for Trampoline implementations with functions with up to two arguments (helpers for more arguments may be added in the future). Use Trampoline.Result<T> (where T is the return type of the complete trampolined call structure) as the return type of any involved method. Normal methods invoked from inside a Trampoline must either be called as a subcall and the result packed into a Trampoline.Result instance using result(T) or they can be wrapped into a Trampoline.Result using bounceWrapped(java.util.function.Supplier<T>).

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Trampoline.Result<T>

Constructor Summary

Constructors

Constructor and Description
Trampoline()

Method Summary

Modifier and Type	Method and Description
static <T,A,B> Trampoline.Result<T>	bounce(java.util.function.BiFunction<A,B,Trampoline.Result<T>> f, A param0, B param1)
static <T,A> Trampoline.Result<T>	bounce(java.util.function.Function<A,Trampoline.Result<T>> f, A param0)
static <T> Trampoline.Result<T>	bounce(java.util.function.Supplier<Trampoline.Result<T>> f)
static <T,A,B> Trampoline.Result<T>	bounceWrapped(java.util.function.BiFunction<A,B,T> f, A param0, B param1)
static <T,A> Trampoline.Result<T>	bounceWrapped(java.util.function.Function<A,T> f, A param0)
static <T> Trampoline.Result<T>	bounceWrapped(java.util.function.Supplier<T> f)
static <T> Trampoline.Result<T>	result(T value)
static <T> T	run(Trampoline.Result<T> result)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Trampoline

public Trampoline()

Method Detail

result

public static <T> Trampoline.Result<T> result(T value)

bounce

public static <T> Trampoline.Result<T> bounce(java.util.function.Supplier<Trampoline.Result<T>> f)

bounce

public static <T,A> Trampoline.Result<T> bounce(java.util.function.Function<A,Trampoline.Result<T>> f,
                                                A param0)

bounce

public static <T,A,B> Trampoline.Result<T> bounce(java.util.function.BiFunction<A,B,Trampoline.Result<T>> f,
                                                  A param0,
                                                  B param1)

bounceWrapped

public static <T> Trampoline.Result<T> bounceWrapped(java.util.function.Supplier<T> f)

bounceWrapped

public static <T,A> Trampoline.Result<T> bounceWrapped(java.util.function.Function<A,T> f,
                                                       A param0)

bounceWrapped

public static <T,A,B> Trampoline.Result<T> bounceWrapped(java.util.function.BiFunction<A,B,T> f,
                                                         A param0,
                                                         B param1)

run

public static <T> T run(Trampoline.Result<T> result)