Another update from ingydotnet^djgoku
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Ingy döt Net
parent
91df62d461
commit
948b86eafa
7604 changed files with 108452 additions and 22726 deletions
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@ -1,53 +1,7 @@
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interface Function<A, B> {
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public B call(A x);
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}
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public class YCombinator {
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interface RecursiveFunc<F> extends Function<RecursiveFunc<F>, F> { }
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public static <A,B> Function<A,B> fix(final Function<Function<A,B>, Function<A,B>> f) {
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RecursiveFunc<Function<A,B>> r =
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new RecursiveFunc<Function<A,B>>() {
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public Function<A,B> call(final RecursiveFunc<Function<A,B>> w) {
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return f.call(new Function<A,B>() {
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public B call(A x) {
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return w.call(w).call(x);
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}
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});
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}
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};
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return r.call(r);
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public static <A,B> Function<A,B> Y(Function<Function<A,B>, Function<A,B>> f) {
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return new Function<A,B>() {
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public B apply(A x) {
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return f.apply(this).apply(x);
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}
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};
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}
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public static void main(String[] args) {
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Function<Function<Integer,Integer>, Function<Integer,Integer>> almost_fib =
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new Function<Function<Integer,Integer>, Function<Integer,Integer>>() {
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public Function<Integer,Integer> call(final Function<Integer,Integer> f) {
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return new Function<Integer,Integer>() {
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public Integer call(Integer n) {
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if (n <= 2) return 1;
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return f.call(n - 1) + f.call(n - 2);
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}
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};
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}
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};
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Function<Function<Integer,Integer>, Function<Integer,Integer>> almost_fac =
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new Function<Function<Integer,Integer>, Function<Integer,Integer>>() {
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public Function<Integer,Integer> call(final Function<Integer,Integer> f) {
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return new Function<Integer,Integer>() {
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public Integer call(Integer n) {
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if (n <= 1) return 1;
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return n * f.call(n - 1);
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}
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};
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}
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};
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Function<Integer,Integer> fib = fix(almost_fib);
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Function<Integer,Integer> fac = fix(almost_fac);
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System.out.println("fib(10) = " + fib.call(10));
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System.out.println("fac(10) = " + fac.call(10));
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}
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}
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@ -1,8 +1,53 @@
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import java.util.function.Function;
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@FunctionalInterface
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public interface SelfApplicable<OUTPUT> extends Function<SelfApplicable<OUTPUT>, OUTPUT> {
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public default OUTPUT selfApply() {
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return apply(this);
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}
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interface Function<A, B> {
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public B call(A x);
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}
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public class YCombinator {
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interface RecursiveFunc<F> extends Function<RecursiveFunc<F>, F> { }
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public static <A,B> Function<A,B> fix(final Function<Function<A,B>, Function<A,B>> f) {
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RecursiveFunc<Function<A,B>> r =
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new RecursiveFunc<Function<A,B>>() {
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public Function<A,B> call(final RecursiveFunc<Function<A,B>> w) {
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return f.call(new Function<A,B>() {
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public B call(A x) {
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return w.call(w).call(x);
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}
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});
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}
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};
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return r.call(r);
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}
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public static void main(String[] args) {
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Function<Function<Integer,Integer>, Function<Integer,Integer>> almost_fib =
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new Function<Function<Integer,Integer>, Function<Integer,Integer>>() {
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public Function<Integer,Integer> call(final Function<Integer,Integer> f) {
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return new Function<Integer,Integer>() {
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public Integer call(Integer n) {
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if (n <= 2) return 1;
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return f.call(n - 1) + f.call(n - 2);
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}
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};
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}
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};
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Function<Function<Integer,Integer>, Function<Integer,Integer>> almost_fac =
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new Function<Function<Integer,Integer>, Function<Integer,Integer>>() {
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public Function<Integer,Integer> call(final Function<Integer,Integer> f) {
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return new Function<Integer,Integer>() {
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public Integer call(Integer n) {
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if (n <= 1) return 1;
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return n * f.call(n - 1);
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}
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};
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}
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};
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Function<Integer,Integer> fib = fix(almost_fib);
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Function<Integer,Integer> fac = fix(almost_fac);
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System.out.println("fib(10) = " + fib.call(10));
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System.out.println("fac(10) = " + fac.call(10));
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}
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}
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@ -1,5 +1,8 @@
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import java.util.function.Function;
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import java.util.function.UnaryOperator;
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@FunctionalInterface
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public interface FixedPoint<FUNCTION> extends Function<UnaryOperator<FUNCTION>, FUNCTION> {}
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public interface SelfApplicable<OUTPUT> extends Function<SelfApplicable<OUTPUT>, OUTPUT> {
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public default OUTPUT selfApply() {
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return apply(this);
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}
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}
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@ -1,43 +1,5 @@
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import java.util.Arrays;
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import java.util.Optional;
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import java.util.function.Function;
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import java.util.function.BiFunction;
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import java.util.function.UnaryOperator;
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@FunctionalInterface
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public interface VarargsFunction<INPUTS, OUTPUT> extends Function<INPUTS[], OUTPUT> {
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@SuppressWarnings("unchecked")
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public OUTPUT apply(INPUTS... inputs);
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public static <INPUTS, OUTPUT> VarargsFunction<INPUTS, OUTPUT> from(Function<INPUTS[], OUTPUT> function) {
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return function::apply;
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}
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public static <INPUTS, OUTPUT> VarargsFunction<INPUTS, OUTPUT> upgrade(Function<INPUTS, OUTPUT> function) {
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return inputs -> function.apply(inputs[0]);
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}
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public static <INPUTS, OUTPUT> VarargsFunction<INPUTS, OUTPUT> upgrade(BiFunction<INPUTS, INPUTS, OUTPUT> function) {
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return inputs -> function.apply(inputs[0], inputs[1]);
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}
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@SuppressWarnings("unchecked")
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public default <POST_OUTPUT> VarargsFunction<INPUTS, POST_OUTPUT> andThen(
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VarargsFunction<OUTPUT, POST_OUTPUT> after) {
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return inputs -> after.apply(apply(inputs));
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}
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@SuppressWarnings("unchecked")
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public default Function<INPUTS, OUTPUT> toFunction() {
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return input -> apply(input);
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}
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@SuppressWarnings("unchecked")
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public default BiFunction<INPUTS, INPUTS, OUTPUT> toBiFunction() {
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return (input, input2) -> apply(input, input2);
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}
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@SuppressWarnings("unchecked")
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public default <PRE_INPUTS> VarargsFunction<PRE_INPUTS, OUTPUT> transformArguments(Function<PRE_INPUTS, INPUTS> transformer) {
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return inputs -> apply((INPUTS[]) Arrays.stream(inputs).parallel().map(transformer).toArray());
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}
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}
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public interface FixedPoint<FUNCTION> extends Function<UnaryOperator<FUNCTION>, FUNCTION> {}
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@ -1,74 +1,43 @@
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import java.math.BigDecimal;
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import java.math.BigInteger;
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import java.util.Arrays;
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import java.util.HashMap;
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import java.util.Map;
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import java.util.Optional;
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import java.util.function.Function;
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import java.util.function.UnaryOperator;
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import java.util.stream.Collectors;
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import java.util.stream.LongStream;
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import java.util.function.BiFunction;
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@FunctionalInterface
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public interface Y<FUNCTION> extends SelfApplicable<FixedPoint<FUNCTION>> {
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public static void main(String... arguments) {
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BigInteger TWO = BigInteger.ONE.add(BigInteger.ONE);
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public interface VarargsFunction<INPUTS, OUTPUT> extends Function<INPUTS[], OUTPUT> {
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@SuppressWarnings("unchecked")
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public OUTPUT apply(INPUTS... inputs);
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Function<Number, Long> toLong = Number::longValue;
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Function<Number, BigInteger> toBigInteger = toLong.andThen(BigInteger::valueOf);
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public static <INPUTS, OUTPUT> VarargsFunction<INPUTS, OUTPUT> from(Function<INPUTS[], OUTPUT> function) {
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return function::apply;
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}
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/* Based on https://gist.github.com/aruld/3965968/#comment-604392 */
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Y<VarargsFunction<Number, Number>> combinator = y -> f -> x -> f.apply(y.selfApply().apply(f)).apply(x);
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FixedPoint<VarargsFunction<Number, Number>> fixedPoint = combinator.selfApply();
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public static <INPUTS, OUTPUT> VarargsFunction<INPUTS, OUTPUT> upgrade(Function<INPUTS, OUTPUT> function) {
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return inputs -> function.apply(inputs[0]);
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}
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VarargsFunction<Number, Number> fibonacci = fixedPoint.apply(
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f -> VarargsFunction.upgrade(
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toBigInteger.andThen(
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n -> (n.compareTo(TWO) <= 0)
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? 1
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: new BigInteger(f.apply(n.subtract(BigInteger.ONE)).toString())
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.add(new BigInteger(f.apply(n.subtract(TWO)).toString()))
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)
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)
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);
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public static <INPUTS, OUTPUT> VarargsFunction<INPUTS, OUTPUT> upgrade(BiFunction<INPUTS, INPUTS, OUTPUT> function) {
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return inputs -> function.apply(inputs[0], inputs[1]);
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}
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VarargsFunction<Number, Number> factorial = fixedPoint.apply(
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f -> VarargsFunction.upgrade(
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toBigInteger.andThen(
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n -> (n.compareTo(BigInteger.ONE) <= 0)
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? 1
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: n.multiply(new BigInteger(f.apply(n.subtract(BigInteger.ONE)).toString()))
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)
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)
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);
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@SuppressWarnings("unchecked")
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public default <POST_OUTPUT> VarargsFunction<INPUTS, POST_OUTPUT> andThen(
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VarargsFunction<OUTPUT, POST_OUTPUT> after) {
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return inputs -> after.apply(apply(inputs));
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}
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VarargsFunction<Number, Number> ackermann = fixedPoint.apply(
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f -> VarargsFunction.upgrade(
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(BigInteger m, BigInteger n) -> m.equals(BigInteger.ZERO)
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? n.add(BigInteger.ONE)
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: f.apply(
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m.subtract(BigInteger.ONE),
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n.equals(BigInteger.ZERO)
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? BigInteger.ONE
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: f.apply(m, n.subtract(BigInteger.ONE))
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)
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).transformArguments(toBigInteger)
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);
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@SuppressWarnings("unchecked")
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public default Function<INPUTS, OUTPUT> toFunction() {
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return input -> apply(input);
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}
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Map<String, VarargsFunction<Number, Number>> functions = new HashMap<>();
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functions.put("fibonacci", fibonacci);
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functions.put("factorial", factorial);
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functions.put("ackermann", ackermann);
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@SuppressWarnings("unchecked")
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public default BiFunction<INPUTS, INPUTS, OUTPUT> toBiFunction() {
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return (input, input2) -> apply(input, input2);
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}
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Map<VarargsFunction<Number, Number>, Number[]> parameters = new HashMap<>();
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parameters.put(functions.get("fibonacci"), new Number[]{20});
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parameters.put(functions.get("factorial"), new Number[]{10});
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parameters.put(functions.get("ackermann"), new Number[]{3, 2});
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functions.entrySet().stream().parallel().map(
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entry -> entry.getKey()
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+ Arrays.toString(parameters.get(entry.getValue()))
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+ " = "
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+ entry.getValue().apply(parameters.get(entry.getValue()))
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).forEach(System.out::println);
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@SuppressWarnings("unchecked")
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public default <PRE_INPUTS> VarargsFunction<PRE_INPUTS, OUTPUT> transformArguments(Function<PRE_INPUTS, INPUTS> transformer) {
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return inputs -> apply((INPUTS[]) Arrays.stream(inputs).parallel().map(transformer).toArray());
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}
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}
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@ -1,3 +1,74 @@
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factorial[10] = 3628800
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ackermann[3, 2] = 29
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fibonacci[20] = 6765
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import java.math.BigDecimal;
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import java.math.BigInteger;
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import java.util.Arrays;
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import java.util.HashMap;
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import java.util.Map;
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import java.util.function.Function;
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import java.util.function.UnaryOperator;
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import java.util.stream.Collectors;
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import java.util.stream.LongStream;
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@FunctionalInterface
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public interface Y<FUNCTION> extends SelfApplicable<FixedPoint<FUNCTION>> {
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public static void main(String... arguments) {
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BigInteger TWO = BigInteger.ONE.add(BigInteger.ONE);
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Function<Number, Long> toLong = Number::longValue;
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Function<Number, BigInteger> toBigInteger = toLong.andThen(BigInteger::valueOf);
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/* Based on https://gist.github.com/aruld/3965968/#comment-604392 */
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Y<VarargsFunction<Number, Number>> combinator = y -> f -> x -> f.apply(y.selfApply().apply(f)).apply(x);
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FixedPoint<VarargsFunction<Number, Number>> fixedPoint = combinator.selfApply();
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VarargsFunction<Number, Number> fibonacci = fixedPoint.apply(
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f -> VarargsFunction.upgrade(
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toBigInteger.andThen(
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n -> (n.compareTo(TWO) <= 0)
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? 1
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: new BigInteger(f.apply(n.subtract(BigInteger.ONE)).toString())
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.add(new BigInteger(f.apply(n.subtract(TWO)).toString()))
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)
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)
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);
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VarargsFunction<Number, Number> factorial = fixedPoint.apply(
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f -> VarargsFunction.upgrade(
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toBigInteger.andThen(
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n -> (n.compareTo(BigInteger.ONE) <= 0)
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? 1
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: n.multiply(new BigInteger(f.apply(n.subtract(BigInteger.ONE)).toString()))
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)
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)
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);
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VarargsFunction<Number, Number> ackermann = fixedPoint.apply(
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f -> VarargsFunction.upgrade(
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(BigInteger m, BigInteger n) -> m.equals(BigInteger.ZERO)
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? n.add(BigInteger.ONE)
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: f.apply(
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m.subtract(BigInteger.ONE),
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n.equals(BigInteger.ZERO)
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? BigInteger.ONE
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: f.apply(m, n.subtract(BigInteger.ONE))
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)
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).transformArguments(toBigInteger)
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);
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Map<String, VarargsFunction<Number, Number>> functions = new HashMap<>();
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functions.put("fibonacci", fibonacci);
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functions.put("factorial", factorial);
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functions.put("ackermann", ackermann);
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Map<VarargsFunction<Number, Number>, Number[]> parameters = new HashMap<>();
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parameters.put(functions.get("fibonacci"), new Number[]{20});
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parameters.put(functions.get("factorial"), new Number[]{10});
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parameters.put(functions.get("ackermann"), new Number[]{3, 2});
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functions.entrySet().stream().parallel().map(
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entry -> entry.getKey()
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+ Arrays.toString(parameters.get(entry.getValue()))
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+ " = "
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+ entry.getValue().apply(parameters.get(entry.getValue()))
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).forEach(System.out::println);
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}
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}
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3
Task/Y-combinator/Java/y-combinator-9.java
Normal file
3
Task/Y-combinator/Java/y-combinator-9.java
Normal file
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@ -0,0 +1,3 @@
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factorial[10] = 3628800
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ackermann[3, 2] = 29
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fibonacci[20] = 6765
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