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/*
* Copyright (C) 2002-2022 Sebastiano Vigna
*
* 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.
*/
package PACKAGE;
import java.util.Iterator;
#if KEYS_PRIMITIVE
import java.util.PrimitiveIterator;
#endif
#if KEYS_PRIMITIVE && !KEYS_INT_LONG_DOUBLE
import java.util.Objects;
#endif
#ifdef KEYS_PRIMITIVE
import java.util.function.Consumer;
#endif
/** A type-specific {@link Iterator}; provides an additional method to avoid (un)boxing, and
* the possibility to skip elements.
*
* @see Iterator
*/
#if KEYS_INT_LONG_DOUBLE
public interface KEY_ITERATOR KEY_GENERIC extends JDK_PRIMITIVE_ITERATOR {
#elif KEYS_PRIMITIVE
public interface KEY_ITERATOR KEY_GENERIC extends PrimitiveIterator {
#else
public interface KEY_ITERATOR KEY_GENERIC extends Iterator {
#endif
#if KEYS_PRIMITIVE
/**
* Returns the next element as a primitive type.
*
* @return the next element in the iteration.
* @see Iterator#next()
*/
#if KEYS_INT_LONG_DOUBLE
@Override
#endif
KEY_TYPE NEXT_KEY();
/** {@inheritDoc}
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default KEY_CLASS next() {
return KEY_CLASS.valueOf(NEXT_KEY());
}
#if KEYS_INT_LONG_DOUBLE
// We inherit the canonical primitive forEachRemaining overload.
// Because our primitive Consumer interface extends both the JDK's primitive
// and object Consumer interfaces, calling this method with it would be ambiguous.
// This overload exists to pass it to the proper primitive overload.
/**
* Performs the given action for each remaining element until all elements
* have been processed or the action throws an exception.
*
* WARNING: Overriding this method is almost always a mistake, as this
* overload only exists to disambiguate. Instead, override the {@code forEachRemaining()} overload
* that uses the JDK's primitive consumer type (e.g. {@link java.util.function.IntConsumer}).
*
*
If Java supported final default methods, this would be one, but sadly it does not.
*
*
If you checked and are overriding the version with {@code java.util.function.XConsumer}, and
* still see this warning, then your IDE is incorrectly conflating this method with the proper
* method to override, and you can safely ignore this message.
*
* @param action the action to be performed for each element.
* @see java.util.Iterator#forEachRemaining(java.util.function.Consumer)
* @since 8.5.0
*/
default void forEachRemaining(final KEY_CONSUMER action) {
forEachRemaining((JDK_PRIMITIVE_KEY_CONSUMER) action);
}
#else
/**
* Performs the given action for each remaining element until all elements
* have been processed or the action throws an exception.
*
* @param action the action to be performed for each element.
* @see java.util.Iterator#forEachRemaining(java.util.function.Consumer)
* @since 8.0.0
* @apiNote Implementing classes should generally override this method, and take the default
* implementation of the other overloads which will delegate to this method (after proper
* conversions).
*/
@Override
default void forEachRemaining(final KEY_CONSUMER action) {
Objects.requireNonNull(action);
while (hasNext()) {
action.accept(NEXT_KEY());
}
}
#if !KEY_CLASS_Boolean
/**
* Performs the given action for each remaining element, performing widening primitive casts,
* until all elements have been processed or the action throws an exception.
* @param action the action to be performed for each element.
* @see java.util.Iterator#forEachRemaining(java.util.function.Consumer)
* @since 8.5.0
* @implNote Unless the argument is type-specific, this method will introduce an intermediary
* lambda to perform widening casts. Please use the type-specific overload to avoid this overhead.
*/
default void forEachRemaining(final JDK_PRIMITIVE_KEY_CONSUMER action) {
Objects.requireNonNull(action);
forEachRemaining(action instanceof KEY_CONSUMER ? (KEY_CONSUMER)action : (KEY_CONSUMER)action::accept);
}
#endif
#endif
/** {@inheritDoc}
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default void forEachRemaining(final Consumer action) {
// The instanceof and cast is required for performance. Without it, calls routed through this
// overload using a primitive consumer would go through the slow lambda.
forEachRemaining(action instanceof METHOD_ARG_KEY_CONSUMER ? (METHOD_ARG_KEY_CONSUMER)action : (METHOD_ARG_KEY_CONSUMER) action::accept);
}
#endif
/** Skips the given number of elements.
*
*
The effect of this call is exactly the same as that of calling {@link #next()} for {@code n} times (possibly stopping if {@link #hasNext()} becomes false).
*
* @param n the number of elements to skip.
* @return the number of elements actually skipped.
* @see Iterator#next()
*/
default int skip(final int n) {
if (n < 0) throw new IllegalArgumentException("Argument must be nonnegative: " + n);
int i = n;
while(i-- != 0 && hasNext()) NEXT_KEY();
return n - i - 1;
}
}