package jaskell.util;

import java.util.*;

public interface Tuple<Head, Tail, Last, ButLast> {

int size();

Head head();

Tail tail();

Last last();

ButLast butLast();

Object get(int pos) throws IndexOutOfBoundsException;

default List<Object> toList() {

List<Object> result = new ArrayList<>();

for (int i = 0; i < size(); i++) {

result.add(get(i));

}

return result;

}

default Map<String, Object> toMap(String... keys) throws IllegalArgumentException {

if (keys.length != size()) {

throw new IllegalArgumentException(

String.format("tuple%d has %d fields but %d keys given %s",

size(), size(), keys.length, Arrays.asList(keys)));

}

Map<String, Object> result = new HashMap<>();

for (int pos = 0; pos < keys.length; pos++) {

result.put(keys[pos], get(pos));

}

return result;

}

static <T, U> Tuple2<T, U> tuple(T t, U u) {

return new Tuple2<>(t, u);

}

static <T, U, V> Tuple3<T, U, V> tuple(T t, U u, V v) {

return new Tuple3<>(t, u, v);

}

static <T, U, V, W> Tuple4<T, U, V, W> tuple(T t, U u, V v, W w) {

return new Tuple4<>(t, u, v, w);

}

static <T, U, V, W, X> Tuple5<T, U, V, W, X> tuple(T t, U u, V v, W w, X x) {

return new Tuple5<>(t, u, v, w, x);

}

static <T, U, V, W, X, Y> Tuple6<T, U, V, W, X, Y> tuple(T t, U u, V v, W w, X x, Y y){

return new Tuple6<>(t, u, v, w, x, y);

}

static <T, U, V, W, X, Y, Z> Tuple7<T, U, V, W, X, Y, Z> tuple(T t, U u, V v, W w, X x, Y y, Z z){

return new Tuple7<>(t, u, v, w, x, y, z);

}

static <S, T, U, V, W, X, Y, Z> Tuple8<S, T, U, V, W, X, Y, Z> tuple(S s, T t, U u, V v, W w, X x, Y y, Z z){

return new Tuple8<>(s, t, u, v, w, x, y, z);

}

}