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/*
* Copyright (C) 2020-2024 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.Collection;
import java.util.RandomAccess;
import java.util.NoSuchElementException;
#if KEYS_REFERENCE
import java.lang.reflect.Array;
import java.util.function.Consumer;
import java.util.stream.Collector;
#endif
/** A type-specific array-based immutable list; provides some additional methods that use polymorphism to avoid (un)boxing.
*
* Instances of this class are immutable
* and (contrarily to mutable array-based list implementations) the backing array is not exposed.
* Instances can be built using a variety of methods, but note that constructors using
* an array will not make a defensive copy.
*
*
This class implements the bulk method {@code getElements()} using
* high-performance system calls (e.g., {@link
* System#arraycopy(Object,int,Object,int,int) System.arraycopy()}) instead of
* expensive loops.
*/
public class IMMUTABLE_LIST KEY_GENERIC extends LISTS.ImmutableListBase KEY_GENERIC implements LIST KEY_GENERIC, RandomAccess, Cloneable, java.io.Serializable {
private static final long serialVersionUID = 0L;
SUPPRESS_WARNINGS_KEY_UNCHECKED_RAWTYPES
static final IMMUTABLE_LIST EMPTY = new IMMUTABLE_LIST(ARRAYS.EMPTY_ARRAY);
#if KEYS_PRIMITIVE
#define _EMPTY_ARRAY ARRAYS.EMPTY_ARRAY
#else
SUPPRESS_WARNINGS_KEY_UNCHECKED
private static final KEY_GENERIC KEY_GENERIC_TYPE[] emptyArray() {
return KEY_GENERIC_ARRAY_CAST ARRAYS.EMPTY_ARRAY;
}
#define _EMPTY_ARRAY emptyArray()
#endif
/** The backing array; all elements are part of this list. */
private final KEY_GENERIC_TYPE[] a;
/** Creates a new immutable list using a given array.
*
*
Note that this constructor does not perform a defensive copy.
*
* @param a the array that will be used to back this immutable list.
*/
public IMMUTABLE_LIST(final KEY_GENERIC_TYPE[] a) {
this.a = a;
}
/** Creates a new immutable list and fills it with a given collection.
*
* @param c a collection that will be used to fill the immutable list.
*/
public IMMUTABLE_LIST(final Collection c) {
#if KEYS_PRIMITIVE
this(c.isEmpty() ? _EMPTY_ARRAY : ITERATORS.unwrap( ITERATORS.AS_KEY_ITERATOR(c.iterator())));
#else
this(c.isEmpty() ? _EMPTY_ARRAY : ITERATORS.unwrap(c.iterator()));
#endif
}
/** Creates a new immutable list and fills it with a given type-specific collection.
*
* @param c a type-specific collection that will be used to fill the immutable list.
*/
public IMMUTABLE_LIST(final COLLECTION KEY_EXTENDS_GENERIC c) {
this(c.isEmpty() ? _EMPTY_ARRAY : ITERATORS.unwrap(c.iterator()));
}
/** Creates a new immutable list and fills it with a given type-specific list.
*
* @param l a type-specific list that will be used to fill the immutable list.
*/
SUPPRESS_WARNINGS_KEY_UNCHECKED
public IMMUTABLE_LIST(final LIST KEY_EXTENDS_GENERIC l) {
this(l.isEmpty() ? _EMPTY_ARRAY : KEY_GENERIC_ARRAY_CAST new KEY_TYPE[l.size()]);
l.getElements(0, a, 0, l.size());
}
/** Creates a new immutable list and fills it with the elements of a given array.
*
* @param a an array whose elements will be used to fill the immutable list.
* @param offset the first element to use.
* @param length the number of elements to use.
*/
SUPPRESS_WARNINGS_KEY_UNCHECKED
public IMMUTABLE_LIST(final KEY_GENERIC_TYPE[] a, final int offset, final int length) {
this(length == 0 ? _EMPTY_ARRAY : KEY_GENERIC_ARRAY_CAST new KEY_TYPE[length]);
System.arraycopy(a, offset, this.a, 0, length);
}
/** Creates a new immutable list and fills it with the elements returned by a type-specific iterator..
*
* @param i a type-specific iterator whose returned elements will fill the immutable list.
*/
public IMMUTABLE_LIST(final KEY_ITERATOR KEY_EXTENDS_GENERIC i) {
this(i.hasNext() ? ITERATORS.unwrap(i) : _EMPTY_ARRAY);
}
/**
* Returns an empty immutable list.
* @return an immutable list (possibly shared) that is empty.
*/
SUPPRESS_WARNINGS_KEY_UNCHECKED
public static KEY_GENERIC IMMUTABLE_LIST KEY_GENERIC of() {
return EMPTY;
}
/** Creates an immutable list using a list of elements.
*
*
Note that this method does not perform a defensive copy.
*
* @param init a list of elements that will be used to initialize the list.
* @return a new immutable list containing the given elements.
*/
SAFE_VARARGS
public static KEY_GENERIC IMMUTABLE_LIST KEY_GENERIC of(final KEY_GENERIC_TYPE... init) {
return init.length == 0 ? of() : new IMMUTABLE_LIST KEY_GENERIC(init);
}
#if KEYS_INT_LONG_DOUBLE || KEYS_REFERENCE
private static KEY_GENERIC IMMUTABLE_LIST KEY_GENERIC convertTrustedToImmutableList(ARRAY_LIST KEY_GENERIC arrayList) {
if (arrayList.isEmpty()) {
return of();
}
KEY_GENERIC_TYPE[] backingArray = arrayList.elements();
if (arrayList.size() != backingArray.length) {
backingArray = java.util.Arrays.copyOf(backingArray, arrayList.size());
}
return new IMMUTABLE_LIST KEY_GENERIC_DIAMOND (backingArray);
}
#endif
#if KEYS_INT_LONG_DOUBLE
/** Collects the result of a primitive {@code Stream} into a new ImmutableList.
*
*
This method performs a terminal operation on the given {@code Stream}
*
* @apiNote Taking a primitive stream instead of returning something like a
* {@link java.util.stream.Collector Collector} is necessary because there is no
* primitive {@code Collector} equivalent in the Java API.
*/
public static KEY_GENERIC IMMUTABLE_LIST KEY_GENERIC toList(JDK_PRIMITIVE_STREAM stream) {
return convertTrustedToImmutableList(ARRAY_LIST.toList(stream));
}
/** Collects the result of a primitive {@code Stream} into a new ImmutableList, potentially pre-allocated to handle the given size.
*
*
This method performs a terminal operation on the given {@code Stream}
*
* @apiNote Taking a primitive stream instead returning something like a
* {@link java.util.stream.Collector Collector} is necessary because there is no
* primitive {@code Collector} equivalent in the Java API.
*/
public static KEY_GENERIC IMMUTABLE_LIST KEY_GENERIC toListWithExpectedSize(JDK_PRIMITIVE_STREAM stream, int expectedSize) {
return convertTrustedToImmutableList(ARRAY_LIST.toListWithExpectedSize(stream, expectedSize));
}
#elif KEYS_REFERENCE
private static final Collector> TO_LIST_COLLECTOR =
Collector.of(
ARRAY_LIST::new,
ARRAY_LIST::add,
ARRAY_LIST::combine,
IMMUTABLE_LIST::convertTrustedToImmutableList);
/** Returns a {@link Collector} that collects a {@code Stream}'s elements into a new ImmutableList. */
SUPPRESS_WARNINGS_KEY_UNCHECKED_RAWTYPES
public static KEY_GENERIC Collector toList() {
return (Collector) TO_LIST_COLLECTOR;
}
/** Returns a {@link Collector} that collects a {@code Stream}'s elements into a new ImmutableList, potentially pre-allocated to handle the given size. */
public static KEY_GENERIC Collector toListWithExpectedSize(int expectedSize) {
if (expectedSize <= ARRAY_LIST.DEFAULT_INITIAL_CAPACITY) {
// Already below default capacity. Just use all default construction instead of fiddling with atomics in SizeDecreasingSupplier
return toList();
}
return Collector.of(
new COLLECTIONS.SizeDecreasingSupplier<
#if KEYS_REFERENCE
K,
#endif
ARRAY_LIST KEY_GENERIC>(
expectedSize, (int size) ->
size <= ARRAY_LIST.DEFAULT_INITIAL_CAPACITY ? new ARRAY_LIST KEY_GENERIC() : new ARRAY_LIST KEY_GENERIC(size)),
ARRAY_LIST::add,
ARRAY_LIST::combine,
IMMUTABLE_LIST::convertTrustedToImmutableList);
}
#endif
@Override
public KEY_GENERIC_TYPE GET_KEY(final int index) {
if (index >= a.length) throw new IndexOutOfBoundsException("Index (" + index + ") is greater than or equal to list size (" + a.length + ")");
return a[index];
}
@Override
public int indexOf(final KEY_TYPE k) {
final KEY_TYPE[] a = this.a;
for(int i = 0, size = a.length; i < size; i++) if (KEY_EQUALS(k, a[i])) return i;
return -1;
}
@Override
public int lastIndexOf(final KEY_TYPE k) {
final KEY_TYPE[] a = this.a;
for(int i = a.length; i-- != 0;) if (KEY_EQUALS(k, a[i])) return i;
return -1;
}
@Override
public int size() {
return a.length;
}
@Override
public boolean isEmpty() {
return a.length == 0;
}
/** Copies element of this type-specific list into the given array using optimized system calls.
*
* @param from the start index (inclusive).
* @param a the destination array.
* @param offset the offset into the destination array where to store the first element copied.
* @param length the number of elements to be copied.
*/
@Override
public void getElements(final int from, final KEY_TYPE[] a, final int offset, final int length) {
ARRAYS.ensureOffsetLength(a, offset, length);
System.arraycopy(this.a, from, a, offset, length);
}
@Override
public void forEach(final METHOD_ARG_KEY_CONSUMER action) {
final KEY_GENERIC_TYPE[] a = this.a;
for (int i = 0; i < a.length; ++i) {
action.accept(a[i]);
}
}
#if KEYS_PRIMITIVE
@Override
public KEY_TYPE[] TO_KEY_ARRAY() {
if (a.length == 0) return ARRAYS.EMPTY_ARRAY;
return a.clone();
}
@Override
public KEY_TYPE[] toArray(KEY_TYPE[] a) {
if (a == null || a.length < size()) a = new KEY_TYPE[this.a.length];
System.arraycopy(this.a, 0, a, 0, size());
return a;
}
#else // KEYS_REFERENCE
@Override
public Object[] toArray() {
// A subtle part of the spec says the returned array must be Object[] exactly.
if (a.length == 0) return it.unimi.dsi.fastutil.objects.ObjectArrays.EMPTY_ARRAY;
if (a.getClass() == Object[].class) return a.clone();
return java.util.Arrays.copyOf(a, a.length, Object[].class);
}
SUPPRESS_WARNINGS_KEY_UNCHECKED
@Override
public T[] toArray(T[] a) {
if (a == null) {
a = (T[]) new Object[size()];
} else if (a.length < size()) {
a = (T[]) Array.newInstance(a.getClass().getComponentType(), size());
}
System.arraycopy(this.a, 0, a, 0, size());
if (a.length > size()) {
a[size()] = null;
}
return a;
}
#endif
@Override
public KEY_LIST_ITERATOR KEY_GENERIC listIterator(final int index) {
ensureIndex(index);
return new KEY_LIST_ITERATOR KEY_GENERIC() {
int pos = index;
@Override
public boolean hasNext() { return pos < a.length; }
@Override
public boolean hasPrevious() { return pos > 0; }
@Override
public KEY_GENERIC_TYPE NEXT_KEY() { if (! hasNext()) throw new NoSuchElementException(); return a[pos++]; }
@Override
public KEY_GENERIC_TYPE PREV_KEY() { if (! hasPrevious()) throw new NoSuchElementException(); return a[--pos]; }
@Override
public int nextIndex() { return pos; }
@Override
public int previousIndex() { return pos - 1; }
@Override
public void forEachRemaining(final METHOD_ARG_KEY_CONSUMER action) {
final KEY_GENERIC_TYPE[] a = IMMUTABLE_LIST.this.a;
while (pos < a.length) {
action.accept(a[pos++]);
}
}
@Override
public void add(KEY_GENERIC_TYPE k) {
throw new UnsupportedOperationException();
}
@Override
public void set(KEY_GENERIC_TYPE k) {
throw new UnsupportedOperationException();
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
@Override
public int back(int n) {
if (n < 0) throw new IllegalArgumentException("Argument must be nonnegative: " + n);
final int remaining = pos;
if (n < remaining) {
pos -= n;
} else {
n = remaining;
pos = 0;
}
return n;
}
@Override
public int skip(int n) {
if (n < 0) throw new IllegalArgumentException("Argument must be nonnegative: " + n);
final int remaining = a.length - pos;
if (n < remaining) {
pos += n;
} else {
n = remaining;
pos = a.length;
}
return n;
}
};
}
private final class Spliterator implements KEY_SPLITERATOR KEY_GENERIC {
int pos, max;
#ifdef TEST
// Sentinel to make sure we don't accidentally use size when we mean max
@Deprecated
private final Object size = null;
#endif
public Spliterator() {
this(0, a.length);
}
private Spliterator(int pos, int max) {
assert pos <= max : "pos " + pos + " must be <= max " + max;
this.pos = pos;
this.max = max;
}
@Override
public int characteristics() { return SPLITERATORS.LIST_SPLITERATOR_CHARACTERISTICS | java.util.Spliterator.IMMUTABLE; }
@Override
public long estimateSize() { return max - pos; }
@Override
public boolean tryAdvance(final METHOD_ARG_KEY_CONSUMER action) {
if (pos >= max) return false;
action.accept(a[pos++]);
return true;
}
@Override
public void forEachRemaining(final METHOD_ARG_KEY_CONSUMER action) {
final KEY_GENERIC_TYPE[] a = IMMUTABLE_LIST.this.a;
for (; pos < max; ++pos) {
action.accept(a[pos]);
}
}
@Override
public long skip(long n) {
if (n < 0) throw new IllegalArgumentException("Argument must be nonnegative: " + n);
if (pos >= max) return 0;
final int remaining = max - pos;
if (n < remaining) {
pos = it.unimi.dsi.fastutil.SafeMath.safeLongToInt(pos + n);
return n;
}
n = remaining;
pos = max;
return n;
}
@Override
public KEY_SPLITERATOR KEY_GENERIC trySplit() {
int retLen = (max - pos) >> 1;
if (retLen <= 1) return null;
int myNewPos = pos + retLen;
int retMax = myNewPos;
int oldPos = pos;
this.pos = myNewPos;
return new Spliterator(oldPos, retMax);
}
}
@Override
public KEY_SPLITERATOR KEY_GENERIC spliterator() {
return new Spliterator();
}
private final static class ImmutableSubList KEY_GENERIC extends LISTS.ImmutableListBase KEY_GENERIC implements java.util.RandomAccess, java.io.Serializable {
private static final long serialVersionUID = 7054639518438982401L;
final IMMUTABLE_LIST KEY_GENERIC innerList;
final int from;
final int to;
/**
* An alias to {@code innerList}'s array to save some typing. Note that 0 in this array is actually
* the first element of the {@code innerList}, not this sublist. {@code a[from]} is the
* first element of this sublist.
*/
final transient KEY_GENERIC_TYPE[] a;
/** No validation; callers must validate arguments. */
ImmutableSubList(IMMUTABLE_LIST KEY_GENERIC innerList, int from, int to) {
this.innerList = innerList;
this.from = from;
this.to = to;
this.a = innerList.a;
}
@Override
public KEY_GENERIC_TYPE GET_KEY(final int index) {
ensureRestrictedIndex(index);
return a[index + from];
}
@Override
public int indexOf(final KEY_TYPE k) {
final KEY_TYPE[] a = this.a;
for(int i = from; i < to; i++) if (KEY_EQUALS(k, a[i])) return i - from;
return -1;
}
@Override
public int lastIndexOf(final KEY_TYPE k) {
final KEY_TYPE[] a = this.a;
for(int i = to; i-- != from;) if (KEY_EQUALS(k, a[i])) return i - from;
return -1;
}
@Override
public int size() {
return to - from;
}
@Override
public boolean isEmpty() {
return to <= from;
}
@Override
public void getElements(final int fromSublistIndex, final KEY_TYPE[] a, final int offset, final int length) {
ARRAYS.ensureOffsetLength(a, offset, length);
ensureRestrictedIndex(fromSublistIndex);
if (from + length > to)
throw new IndexOutOfBoundsException("Final index " + (from + length) + " (startingIndex: " + from + " + length: " + length + ") is greater then list length " + size());
System.arraycopy(this.a, fromSublistIndex + from, a, offset, length);
}
@Override
public void forEach(final METHOD_ARG_KEY_CONSUMER action) {
final KEY_GENERIC_TYPE[] a = this.a;
for (int i = from; i < to; ++i) {
action.accept(a[i]);
}
}
#if KEYS_PRIMITIVE
@Override
public KEY_TYPE[] TO_KEY_ARRAY() {
return java.util.Arrays.copyOfRange(a, from, to);
}
@Override
public KEY_TYPE[] toArray(KEY_TYPE[] a) {
if (a == null || a.length < size()) a = new KEY_TYPE[size()];
System.arraycopy(this.a, from, a, 0, size());
return a;
}
#else // KEYS_REFERENCE
@Override
public Object[] toArray() {
// A subtle part of the spec says the returned array must be Object[] exactly.
return java.util.Arrays.copyOfRange(a, from, to, Object[].class);
}
SUPPRESS_WARNINGS_KEY_UNCHECKED
@Override
public KEY_GENERIC KEY_GENERIC_TYPE[] toArray(KEY_GENERIC_TYPE[] a) {
final int size = size();
if (a == null) {
a = KEY_GENERIC_ARRAY_CAST new Object[size];
} else if (a.length < size) {
a = KEY_GENERIC_ARRAY_CAST Array.newInstance(a.getClass().getComponentType(), size);
}
System.arraycopy(this.a, from, a, 0, size);
if (a.length > size) {
a[size] = null;
}
return a;
}
#endif
@Override
public KEY_LIST_ITERATOR KEY_GENERIC listIterator(final int index) {
ensureIndex(index);
return new KEY_LIST_ITERATOR KEY_GENERIC() {
int pos = index + from;
@Override
public boolean hasNext() { return pos < to; }
@Override
public boolean hasPrevious() { return pos > from; }
@Override
public KEY_GENERIC_TYPE NEXT_KEY() { if (! hasNext()) throw new NoSuchElementException(); return a[pos++]; }
@Override
public KEY_GENERIC_TYPE PREV_KEY() { if (! hasPrevious()) throw new NoSuchElementException(); return a[--pos]; }
@Override
public int nextIndex() { return pos - from; }
@Override
public int previousIndex() { return pos - from - 1; }
@Override
public void forEachRemaining(final METHOD_ARG_KEY_CONSUMER action) {
final KEY_GENERIC_TYPE[] a = ImmutableSubList.this.a;
while (pos < to) {
action.accept(a[pos++]);
}
}
@Override
public void add(KEY_GENERIC_TYPE k) {
throw new UnsupportedOperationException();
}
@Override
public void set(KEY_GENERIC_TYPE k) {
throw new UnsupportedOperationException();
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
@Override
public int back(int n) {
if (n < 0) throw new IllegalArgumentException("Argument must be nonnegative: " + n);
final int remaining = pos - from;
if (n < remaining) {
pos -= n;
} else {
n = remaining;
pos = from;
}
return n;
}
@Override
public int skip(int n) {
if (n < 0) throw new IllegalArgumentException("Argument must be nonnegative: " + n);
final int remaining = to - pos;
if (n < remaining) {
pos += n;
} else {
n = remaining;
pos = to;
}
return n;
}
};
}
private final class SubListSpliterator extends SPLITERATORS.EarlyBindingSizeIndexBasedSpliterator KEY_GENERIC {
// We are using pos == 0 to be 0 relative to real array 0
SubListSpliterator() {
super(from, to);
}
/** No validation; callers must validate arguments. */
private SubListSpliterator(int pos, int maxPos) {
super(pos, maxPos);
}
// Remember, the indexes we are getting is the real array's index, not our sublist relative index.
@Override
protected final KEY_GENERIC_TYPE get(int i) { return a[i]; }
@Override
protected final SubListSpliterator makeForSplit(int pos, int maxPos) {
return new SubListSpliterator(pos, maxPos);
}
@Override
public boolean tryAdvance(final METHOD_ARG_KEY_CONSUMER action) {
if (pos >= maxPos) return false;
action.accept(a[pos++]);
return true;
}
@Override
public void forEachRemaining(final METHOD_ARG_KEY_CONSUMER action) {
final KEY_GENERIC_TYPE[] a = ImmutableSubList.this.a;
final int max = maxPos;
while(pos < max) {
action.accept(a[pos++]);
}
}
@Override
public int characteristics() { return SPLITERATORS.LIST_SPLITERATOR_CHARACTERISTICS | java.util.Spliterator.IMMUTABLE; }
}
@Override
public KEY_SPLITERATOR KEY_GENERIC spliterator() {
return new SubListSpliterator();
}
boolean contentsEquals(KEY_GENERIC_TYPE[] otherA, int otherAFrom, int otherATo) {
if (a == otherA && from == otherAFrom && to == otherATo) {
return true;
}
if (otherATo - otherAFrom != size()) {
return false;
}
int pos = from, otherPos = otherAFrom;
// We have already assured that the two ranges are the same size, so we only need to check one bound.
// TODO When minimum version of Java becomes Java 9, use the Arrays.equals which takes bounds, which is vectorized.
// Make sure to split out the reference equality case when you do this.
#if KEY_CLASS_Object
while(pos < to) if (!java.util.Objects.equals(a[pos++], otherA[otherPos++])) return false;
#else
while(pos < to) if (a[pos++] != otherA[otherPos++]) return false;
#endif
return true;
}
@Override
public boolean equals(Object o) {
if (o == this) return true;
if (o == null) return false;
if (!(o instanceof java.util.List)) return false;
if (o instanceof IMMUTABLE_LIST) {
SUPPRESS_WARNINGS_KEY_UNCHECKED
IMMUTABLE_LIST KEY_GENERIC other = (IMMUTABLE_LIST KEY_GENERIC) o;
return contentsEquals(other.a, 0, other.size());
}
if (o instanceof ImmutableSubList) {
SUPPRESS_WARNINGS_KEY_UNCHECKED
ImmutableSubList KEY_GENERIC other = (ImmutableSubList KEY_GENERIC) o;
return contentsEquals(other.a, other.from, other.to);
}
return super.equals(o);
}
#if ! KEYS_USE_REFERENCE_EQUALITY
SUPPRESS_WARNINGS_KEY_UNCHECKED
int contentsCompareTo(KEY_GENERIC_TYPE[] otherA, int otherAFrom, int otherATo) {
final KEY_GENERIC_TYPE[] a = this.a;
#if KEYS_PRIMITIVE // Can't make this assumption for reference types in case we have a goofy Comparable that doesn't compare itself equal
if (a == otherA && from == otherAFrom && to == otherATo) return 0;
#endif
// TODO When minimum version of Java becomes Java 9, use Arrays.compare, which vectorizes.
KEY_GENERIC_TYPE e1, e2;
int r, i, j;
for(i = from, j = otherAFrom; i < to && i < otherATo; i++, j++) {
e1 = a[i];
e2 = otherA[j];
if ((r = KEY_CMP(e1, e2)) != 0) return r;
}
return i < otherATo ? -1 : (i < to ? 1 : 0);
}
SUPPRESS_WARNINGS_KEY_UNCHECKED
@Override
public int compareTo(final java.util.List l) {
if (l instanceof IMMUTABLE_LIST) {
SUPPRESS_WARNINGS_KEY_UNCHECKED
IMMUTABLE_LIST KEY_GENERIC other = (IMMUTABLE_LIST KEY_GENERIC) l;
return contentsCompareTo(other.a, 0, other.size());
}
if (l instanceof ImmutableSubList) {
SUPPRESS_WARNINGS_KEY_UNCHECKED
ImmutableSubList KEY_GENERIC other = (ImmutableSubList KEY_GENERIC) l;
return contentsCompareTo(other.a, other.from, other.to);
}
return super.compareTo(l);
}
#endif
private Object readResolve() throws java.io.ObjectStreamException {
// We need to recheck the invariants of the subList and reestablish our "a" array alias.
// Easiest way to do this is to just make a subList anew.
// This will not cause a recopy of contents as subLists are a view, so this is all constant time.
try {
return innerList.subList(from, to);
} catch (IllegalArgumentException | IndexOutOfBoundsException ex) {
throw (java.io.InvalidObjectException) (new java.io.InvalidObjectException(ex.getMessage()).initCause(ex));
}
}
SUPPRESS_WARNINGS_KEY_UNCHECKED
@Override
public LIST KEY_GENERIC subList(int from, int to) {
// We don't need to worry about keeping all nested sublists up to date with bounds as we are immutable.
// So don't even nest; just return a sublist with the immediate parent of the root list.
ensureIndex(from);
ensureIndex(to);
if (from == to) return EMPTY;
if (from > to) throw new IllegalArgumentException("Start index (" + from + ") is greater than end index (" + to + ")");
return new ImmutableSubList KEY_GENERIC_DIAMOND(innerList, from + this.from, to + this.from);
}
}
/**
* {@inheritDoc}
*
* @apiNote The returned list will be immutable, but is currently not declared to return an
* instance of {@code ImmutableList} due to complications of implementation details.
* This may change in a future version (in other words, do not consider the return type of
* this method to be stable if making a subclass of {@code ImmutableList}).
*/
SUPPRESS_WARNINGS_KEY_UNCHECKED
@Override
public LIST KEY_GENERIC subList(int from, int to) {
if (from == 0 && to == size()) return this;
ensureIndex(from);
ensureIndex(to);
if (from == to) return EMPTY;
if (from > to) throw new IllegalArgumentException("Start index (" + from + ") is greater than end index (" + to + ")");
return new ImmutableSubList KEY_GENERIC_DIAMOND(this, from, to);
}
@Override
public IMMUTABLE_LIST KEY_GENERIC clone() {
return this;
}
/** Compares this type-specific immutable list to another one.
*
* @apiNote This method exists only for sake of efficiency. The implementation
* inherited from the abstract implementation would already work.
*
* @param l a type-specific immutable list.
* @return true if the argument contains the same elements of this type-specific immutable list.
*/
public boolean equals(final IMMUTABLE_LIST KEY_GENERIC l) {
if (l == this) return true;
if (a == l.a) return true;
int s = size();
if (s != l.size()) return false;
final KEY_GENERIC_TYPE[] a1 = a;
final KEY_GENERIC_TYPE[] a2 = l.a;
#if KEYS_USE_REFERENCE_EQUALITY
while(s-- != 0) if (a1[s] != a2[s]) return false;
return true;
#else
return java.util.Arrays.equals(a1, a2);
#endif
}
#if KEYS_REFERENCE
@SuppressWarnings({"unchecked", "unlikely-arg-type"})
#else
@SuppressWarnings("unlikely-arg-type")
#endif
@Override
public boolean equals(final Object o) {
if (o == this) return true;
if (o == null) return false;
if (!(o instanceof java.util.List)) return false;
if (o instanceof IMMUTABLE_LIST) {
return equals((IMMUTABLE_LIST KEY_GENERIC) o);
}
if (o instanceof ImmutableSubList) {
// Sublist has an optimized sub-array based comparison, reuse that.
return ((ImmutableSubList KEY_GENERIC)o).equals(this);
}
return super.equals(o);
}
#if ! KEYS_USE_REFERENCE_EQUALITY
/** Compares this immutable list to another immutable list.
*
* @apiNote This method exists only for sake of efficiency. The implementation
* inherited from the abstract implementation would already work.
*
* @param l an immutable list.
* @return a negative integer,
* zero, or a positive integer as this list is lexicographically less than, equal
* to, or greater than the argument.
*/
SUPPRESS_WARNINGS_KEY_UNCHECKED
public int compareTo(final IMMUTABLE_LIST KEY_EXTENDS_GENERIC l) {
#if KEYS_PRIMITIVE // Can't make this assumption for reference types in case we have a goofy Comparable that doesn't compare itself equal
if (a == l.a) return 0;
#endif
// TODO When minimum version of Java becomes Java 9, use Arrays.compare, which vectorizes.
final int s1 = size(), s2 = l.size();
final KEY_GENERIC_TYPE[] a1 = a, a2 = l.a;
KEY_GENERIC_TYPE e1, e2;
int r, i;
for(i = 0; i < s1 && i < s2; i++) {
e1 = a1[i];
e2 = a2[i];
if ((r = KEY_CMP(e1, e2)) != 0) return r;
}
return i < s2 ? -1 : (i < s1 ? 1 : 0);
}
SUPPRESS_WARNINGS_KEY_UNCHECKED
@Override
public int compareTo(final java.util.List l) {
if (l instanceof IMMUTABLE_LIST) {
return compareTo((IMMUTABLE_LIST KEY_EXTENDS_GENERIC)l);
}
if (l instanceof ImmutableSubList) {
// Safe to strip the "extends" because we will only ever take elements, never modify them (especially because it is immutable).
ImmutableSubList KEY_GENERIC other = (ImmutableSubList KEY_GENERIC)l;
// Must negate because we are inverting the order of the comparison.
return -other.compareTo(this);
}
return super.compareTo(l);
}
#endif
}
#undef _EMPTY_ARRAY