/*
* Java Genetic Algorithm Library (@__identifier__@).
* Copyright (c) @__year__@ Franz Wilhelmstötter
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Author:
* Franz Wilhelmstötter (franz.wilhelmstoetter@gmx.at)
*/
package org.jenetics.util;
import static java.util.Objects.requireNonNull;
import java.util.ArrayList;
import java.util.List;
import java.util.function.Function;
import java.util.function.Supplier;
import java.util.stream.Collector;
import org.jenetics.internal.collection.Empty;
import org.jenetics.internal.util.require;
/**
* Immutable, ordered, fixed sized sequence.
*
* @see MSeq
*
* @author <a href="mailto:franz.wilhelmstoetter@gmx.at">Franz Wilhelmstötter</a>
* @since 1.0
* @version 3.6
*/
public interface ISeq<T>
extends
Seq<T>,
Copyable<MSeq<T>>
{
@Override
public ISeq<T> subSeq(final int start, final int end);
@Override
public ISeq<T> subSeq(final int start);
@Override
public <B> ISeq<B> map(final Function<? super T, ? extends B> mapper);
@SuppressWarnings("unchecked")
@Override
public default ISeq<T> append(final T... values) {
return append(ISeq.of(values));
}
@Override
public ISeq<T> append(final Iterable<? extends T> values);
@SuppressWarnings("unchecked")
@Override
public default ISeq<T> prepend(final T... values) {
return prepend(ISeq.of(values));
}
@Override
public ISeq<T> prepend(final Iterable<? extends T> values);
/**
* Return a shallow copy of this sequence. The sequence elements are not
* cloned.
*
* @return a shallow copy of this sequence.
*/
@Override
public MSeq<T> copy();
/* *************************************************************************
* Some static factory methods.
* ************************************************************************/
/**
* Single instance of an empty {@code ISeq}.
*
* @since 3.3
*/
public static final ISeq<?> EMPTY = Empty.ISEQ;
/**
* Return an empty {@code ISeq}.
*
* @since 3.3
*
* @param <T> the element type of the returned {@code ISeq}.
* @return an empty {@code ISeq}.
*/
public static <T> ISeq<T> empty() {
return Empty.iseq();
}
/**
* Returns a {@code Collector} that accumulates the input elements into a
* new {@code ISeq}.
*
* @param <T> the type of the input elements
* @return a {@code Collector} which collects all the input elements into an
* {@code ISeq}, in encounter order
*/
public static <T> Collector<T, ?, ISeq<T>> toISeq() {
return Collector.of(
(Supplier<List<T>>)ArrayList::new,
List::add,
(left, right) -> { left.addAll(right); return left; },
ISeq::of
);
}
/**
* Create a new {@code ISeq} from the given values.
*
* @param <T> the element type
* @param values the array values.
* @return a new {@code ISeq} with the given values.
* @throws NullPointerException if the {@code values} array is {@code null}.
*/
@SafeVarargs
public static <T> ISeq<T> of(final T... values) {
return values.length == 0
? empty()
: MSeq.of(values).toISeq();
}
/**
* Create a new {@code ISeq} from the given values.
*
* @param <T> the element type
* @param values the array values.
* @return a new {@code ISeq} with the given values.
* @throws NullPointerException if the {@code values} array is {@code null}.
*/
@SuppressWarnings("unchecked")
public static <T> ISeq<T> of(final Iterable<? extends T> values) {
requireNonNull(values);
return values instanceof ISeq<?>
? (ISeq<T>)values
: values instanceof MSeq<?>
? ((MSeq<T>)values).toISeq()
: MSeq.<T>of(values).toISeq();
}
// /**
// * Create a new {@code ISeq} instance from the remaining elements of the
// * given iterator.
// *
// * @since 3.3
// *
// * @param <T> the element type.
// * @return a new {@code ISeq} with the given remaining values.
// * @throws NullPointerException if the {@code values} object is
// * {@code null}.
// */
// public static <T> ISeq<T> of(final Iterator<? extends T> values) {
// final MSeq<T> seq = MSeq.of(values);
// return seq.isEmpty() ? empty() : seq.toISeq();
// }
/**
* Creates a new sequence, which is filled with objects created be the given
* {@code supplier}.
*
* @since 3.2
*
* @param <T> the element type of the sequence
* @param supplier the {@code Supplier} which creates the elements, the
* returned sequence is filled with
* @param length the length of the returned sequence
* @return a new sequence filled with elements given by the {@code supplier}
* @throws NegativeArraySizeException if the given {@code length} is
* negative
* @throws NullPointerException if the given {@code supplier} is
* {@code null}
*/
public static <T> ISeq<T> of(
final Supplier<? extends T> supplier,
final int length
) {
requireNonNull(supplier);
require.nonNegative(length);
return length == 0
? empty()
: MSeq.<T>ofLength(length).fill(supplier).toISeq();
}
/**
* Allows a safe (without compile warning) upcast from {@code B} to
* {@code A}. Since {@code ISeq} instances are immutable, an <i>upcast</i>
* will be always safe.
*
* <pre>{@code
* // The sequence which we want to case.
* final ISeq<? extends Number> ints = ISeq.of(1, 2, 3, 4, 5);
*
* // This casts are possible without warning.
* final ISeq<Object> objects = ISeq.upcast(ints);
* final ISeq<Number> numbers = ISeq.upcast(ints);
*
* // This cast will, of course, still fail.
* final ISeq<String> strings = ISeq.upcast(ints);
* final ISeq<Integer> integers = ISeq.upcast(ints);
* }</pre>
*
* @since 3.6
*
* @param seq the sequence to cast safely
* @param <A> the <i>super</i>-object type
* @param <B> the <i>sub</i>-object type
* @return the casted instance of the given {@code seq}
*/
@SuppressWarnings("unchecked")
public static <A, B extends A> ISeq<A> upcast(final ISeq<B> seq) {
return (ISeq<A>)seq;
}
}