/*
    * Copyright (C) 2008 The Guava Authors
    *
    * 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 com.google.common.collect;
  
  import static com.google.common.base.Preconditions.checkNotNull;
  
  import com.google.common.annotations.GwtCompatible;
  import com.google.common.base.Equivalence;
  import com.google.common.base.Function;
  import com.google.common.base.Predicate;
  
  import java.io.Serializable;
  import java.util.Comparator;
  import java.util.Iterator;
  import java.util.NoSuchElementException;
  import java.util.SortedSet;
  
  import javax.annotation.Nullable;
  
  /**
   * A range (or "interval") defines the <i>boundaries</i> around a contiguous span of values of some
   * {@code Comparable} type; for example, "integers from 1 to 100 inclusive." Note that it is not
   * possible to <i>iterate</i> over these contained values. To do so, pass this range instance and
   * an appropriate {@link DiscreteDomain} to {@link ContiguousSet#create}.
   *
   * <h3>Types of ranges</h3>
   *
   * <p>Each end of the range may be bounded or unbounded. If bounded, there is an associated
   * <i>endpoint</i> value, and the range is considered to be either <i>open</i> (does not include the
   * endpoint) or <i>closed</i> (includes the endpoint) on that side. With three possibilities on each
   * side, this yields nine basic types of ranges, enumerated below. (Notation: a square bracket
   * ({@code [ ]}) indicates that the range is closed on that side; a parenthesis ({@code ( )}) means
   * it is either open or unbounded. The construct {@code {x | statement}} is read "the set of all
   * <i>x</i> such that <i>statement</i>.")
   *
   * <blockquote><table>
   * <tr><td><b>Notation</b> <td><b>Definition</b>        <td><b>Factory method</b>
   * <tr><td>{@code (a..b)}  <td>{@code {x | a < x < b}}  <td>{@link Range#open open}
   * <tr><td>{@code [a..b]}  <td>{@code {x | a <= x <= b}}<td>{@link Range#closed closed}
   * <tr><td>{@code (a..b]}  <td>{@code {x | a < x <= b}} <td>{@link Range#openClosed openClosed}
   * <tr><td>{@code [a..b)}  <td>{@code {x | a <= x < b}} <td>{@link Range#closedOpen closedOpen}
   * <tr><td>{@code (a..+∞)} <td>{@code {x | x > a}}      <td>{@link Range#greaterThan greaterThan}
   * <tr><td>{@code [a..+∞)} <td>{@code {x | x >= a}}     <td>{@link Range#atLeast atLeast}
   * <tr><td>{@code (-∞..b)} <td>{@code {x | x < b}}      <td>{@link Range#lessThan lessThan}
   * <tr><td>{@code (-∞..b]} <td>{@code {x | x <= b}}     <td>{@link Range#atMost atMost}
   * <tr><td>{@code (-∞..+∞)}<td>{@code {x}}              <td>{@link Range#all all}
   * </table></blockquote>
   *
   * <p>When both endpoints exist, the upper endpoint may not be less than the lower. The endpoints
   * may be equal only if at least one of the bounds is closed:
   *
   * <ul>
   * <li>{@code [a..a]} : a singleton range
   * <li>{@code [a..a); (a..a]} : {@linkplain #isEmpty empty} ranges; also valid
   * <li>{@code (a..a)} : <b>invalid</b>; an exception will be thrown
   * </ul>
   *
   * <h3>Warnings</h3>
   *
   * <ul>
   * <li>Use immutable value types only, if at all possible. If you must use a mutable type, <b>do
   *     not</b> allow the endpoint instances to mutate after the range is created!
   * <li>Your value type's comparison method should be {@linkplain Comparable consistent with equals}
   *     if at all possible. Otherwise, be aware that concepts used throughout this documentation such
   *     as "equal", "same", "unique" and so on actually refer to whether {@link Comparable#compareTo
   *     compareTo} returns zero, not whether {@link Object#equals equals} returns {@code true}.
   * <li>A class which implements {@code Comparable<UnrelatedType>} is very broken, and will cause
   *     undefined horrible things to happen in {@code Range}. For now, the Range API does not prevent
   *     its use, because this would also rule out all ungenerified (pre-JDK1.5) data types. <b>This
   *     may change in the future.</b>
   * </ul>
   *
   * <h3>Other notes</h3>
   *
   * <ul>
   * <li>Instances of this type are obtained using the static factory methods in this class.
   * <li>Ranges are <i>convex</i>: whenever two values are contained, all values in between them must
   *     also be contained. More formally, for any {@code c1 <= c2 <= c3} of type {@code C}, {@code
   *     r.contains(c1) && r.contains(c3)} implies {@code r.contains(c2)}). This means that a {@code
   *     Range<Integer>} can never be used to represent, say, "all <i>prime</i> numbers from 1 to
   *     100."
   * <li>When evaluated as a {@link Predicate}, a range yields the same result as invoking {@link
   *     #contains}.
   * <li>Terminology note: a range {@code a} is said to be the <i>maximal</i> range having property
   *     <i>P</i> if, for all ranges {@code b} also having property <i>P</i>, {@code a.encloses(b)}.
  *     Likewise, {@code a} is <i>minimal</i> when {@code b.encloses(a)} for all {@code b} having
  *     property <i>P</i>. See, for example, the definition of {@link #intersection intersection}.
  * </ul>
  *
  * <h3>Further reading</h3>
  *
  * <p>See the Guava User Guide article on
  * <a href="http://code.google.com/p/guava-libraries/wiki/RangesExplained">{@code Range}</a>.
  *
  * @author Kevin Bourrillion
  * @author Gregory Kick
  * @since 10.0
  */
 @GwtCompatible
 @SuppressWarnings("rawtypes")
 public final class Range<C extends Comparable> implements Predicate<C>, Serializable {
 
   private static final Function<Range, Cut> LOWER_BOUND_FN = new Function<Range, Cut>() {
     @Override
     public Cut apply(Range range) {
       return range.lowerBound;
     }
   };
 
   @SuppressWarnings("unchecked")
   static <C extends Comparable<?>> Function<Range<C>, Cut<C>> lowerBoundFn() {
     return (Function) LOWER_BOUND_FN;
   }
 
   private static final Function<Range, Cut> UPPER_BOUND_FN = new Function<Range, Cut>() {
     @Override
     public Cut apply(Range range) {
       return range.upperBound;
     }
   };
 
   @SuppressWarnings("unchecked")
   static <C extends Comparable<?>> Function<Range<C>, Cut<C>> upperBoundFn() {
     return (Function) UPPER_BOUND_FN;
   }
 
   static final Ordering<Range<?>> RANGE_LEX_ORDERING = new Ordering<Range<?>>() {
     @Override
     public int compare(Range<?> left, Range<?> right) {
       return ComparisonChain.start()
           .compare(left.lowerBound, right.lowerBound)
           .compare(left.upperBound, right.upperBound)
           .result();
     }
   };
 
   static <C extends Comparable<?>> Range<C> create(
       Cut<C> lowerBound, Cut<C> upperBound) {
     return new Range<C>(lowerBound, upperBound);
   }
 
   /**
    * Returns a range that contains all values strictly greater than {@code
    * lower} and strictly less than {@code upper}.
    *
    * @throws IllegalArgumentException if {@code lower} is greater than <i>or
    *     equal to</i> {@code upper}
    * @since 14.0
    */
   public static <C extends Comparable<?>> Range<C> open(C lower, C upper) {
     return create(Cut.aboveValue(lower), Cut.belowValue(upper));
   }
 
   /**
    * Returns a range that contains all values greater than or equal to
    * {@code lower} and less than or equal to {@code upper}.
    *
    * @throws IllegalArgumentException if {@code lower} is greater than {@code
    *     upper}
    * @since 14.0
    */
   public static <C extends Comparable<?>> Range<C> closed(C lower, C upper) {
     return create(Cut.belowValue(lower), Cut.aboveValue(upper));
   }
 
   /**
    * Returns a range that contains all values greater than or equal to
    * {@code lower} and strictly less than {@code upper}.
    *
    * @throws IllegalArgumentException if {@code lower} is greater than {@code
    *     upper}
    * @since 14.0
    */
   public static <C extends Comparable<?>> Range<C> closedOpen(
       C lower, C upper) {
     return create(Cut.belowValue(lower), Cut.belowValue(upper));
   }
 
   /**
    * Returns a range that contains all values strictly greater than {@code
    * lower} and less than or equal to {@code upper}.
    *
    * @throws IllegalArgumentException if {@code lower} is greater than {@code
    *     upper}
    * @since 14.0
    */
   public static <C extends Comparable<?>> Range<C> openClosed(
       C lower, C upper) {
     return create(Cut.aboveValue(lower), Cut.aboveValue(upper));
   }
 
   /**
    * Returns a range that contains any value from {@code lower} to {@code
    * upper}, where each endpoint may be either inclusive (closed) or exclusive
    * (open).
    *
    * @throws IllegalArgumentException if {@code lower} is greater than {@code
    *     upper}
    * @since 14.0
    */
   public static <C extends Comparable<?>> Range<C> range(
       C lower, BoundType lowerType, C upper, BoundType upperType) {
     checkNotNull(lowerType);
     checkNotNull(upperType);
 
     Cut<C> lowerBound = (lowerType == BoundType.OPEN)
         ? Cut.aboveValue(lower)
         : Cut.belowValue(lower);
     Cut<C> upperBound = (upperType == BoundType.OPEN)
         ? Cut.belowValue(upper)
         : Cut.aboveValue(upper);
     return create(lowerBound, upperBound);
   }
 
   /**
    * Returns a range that contains all values strictly less than {@code
    * endpoint}.
    *
    * @since 14.0
    */
   public static <C extends Comparable<?>> Range<C> lessThan(C endpoint) {
     return create(Cut.<C>belowAll(), Cut.belowValue(endpoint));
   }
 
   /**
    * Returns a range that contains all values less than or equal to
    * {@code endpoint}.
    *
    * @since 14.0
    */
   public static <C extends Comparable<?>> Range<C> atMost(C endpoint) {
     return create(Cut.<C>belowAll(), Cut.aboveValue(endpoint));
   }
 
   /**
    * Returns a range with no lower bound up to the given endpoint, which may be
    * either inclusive (closed) or exclusive (open).
    *
    * @since 14.0
    */
   public static <C extends Comparable<?>> Range<C> upTo(
       C endpoint, BoundType boundType) {
     switch (boundType) {
       case OPEN:
         return lessThan(endpoint);
       case CLOSED:
         return atMost(endpoint);
       default:
         throw new AssertionError();
     }
   }
 
   /**
    * Returns a range that contains all values strictly greater than {@code
    * endpoint}.
    *
    * @since 14.0
    */
   public static <C extends Comparable<?>> Range<C> greaterThan(C endpoint) {
     return create(Cut.aboveValue(endpoint), Cut.<C>aboveAll());
   }
 
   /**
    * Returns a range that contains all values greater than or equal to
    * {@code endpoint}.
    *
    * @since 14.0
    */
   public static <C extends Comparable<?>> Range<C> atLeast(C endpoint) {
     return create(Cut.belowValue(endpoint), Cut.<C>aboveAll());
   }
 
   /**
    * Returns a range from the given endpoint, which may be either inclusive
    * (closed) or exclusive (open), with no upper bound.
    *
    * @since 14.0
    */
   public static <C extends Comparable<?>> Range<C> downTo(
       C endpoint, BoundType boundType) {
     switch (boundType) {
       case OPEN:
         return greaterThan(endpoint);
       case CLOSED:
         return atLeast(endpoint);
       default:
         throw new AssertionError();
     }
   }
 
   private static final Range<Comparable> ALL =
       new Range<Comparable>(Cut.belowAll(), Cut.aboveAll());
 
   /**
    * Returns a range that contains every value of type {@code C}.
    *
    * @since 14.0
    */
   @SuppressWarnings("unchecked")
   public static <C extends Comparable<?>> Range<C> all() {
     return (Range) ALL;
   }
 
   /**
    * Returns a range that {@linkplain Range#contains(Comparable) contains} only
    * the given value. The returned range is {@linkplain BoundType#CLOSED closed}
    * on both ends.
    *
    * @since 14.0
    */
   public static <C extends Comparable<?>> Range<C> singleton(C value) {
     return closed(value, value);
   }
 
    /**
    * Returns the minimal range that
    * {@linkplain Range#contains(Comparable) contains} all of the given values.
    * The returned range is {@linkplain BoundType#CLOSED closed} on both ends.
    *
    * @throws ClassCastException if the parameters are not <i>mutually
    *     comparable</i>
    * @throws NoSuchElementException if {@code values} is empty
    * @throws NullPointerException if any of {@code values} is null
    * @since 14.0
    */
   public static <C extends Comparable<?>> Range<C> encloseAll(
       Iterable<C> values) {
     checkNotNull(values);
     if (values instanceof ContiguousSet) {
       return ((ContiguousSet<C>) values).range();
     }
     Iterator<C> valueIterator = values.iterator();
     C min = checkNotNull(valueIterator.next());
     C max = min;
     while (valueIterator.hasNext()) {
       C value = checkNotNull(valueIterator.next());
       min = Ordering.natural().min(min, value);
       max = Ordering.natural().max(max, value);
     }
     return closed(min, max);
   }
 
   final Cut<C> lowerBound;
   final Cut<C> upperBound;
 
   private Range(Cut<C> lowerBound, Cut<C> upperBound) {
     if (lowerBound.compareTo(upperBound) > 0 || lowerBound == Cut.<C>aboveAll()
         || upperBound == Cut.<C>belowAll()) {
       throw new IllegalArgumentException("Invalid range: " + toString(lowerBound, upperBound));
     }
     this.lowerBound = checkNotNull(lowerBound);
     this.upperBound = checkNotNull(upperBound);
   }
 
   /**
    * Returns {@code true} if this range has a lower endpoint.
    */
   public boolean hasLowerBound() {
     return lowerBound != Cut.belowAll();
   }
 
   /**
    * Returns the lower endpoint of this range.
    *
    * @throws IllegalStateException if this range is unbounded below (that is, {@link
    *     #hasLowerBound()} returns {@code false})
    */
   public C lowerEndpoint() {
     return lowerBound.endpoint();
   }
 
   /**
    * Returns the type of this range's lower bound: {@link BoundType#CLOSED} if the range includes
    * its lower endpoint, {@link BoundType#OPEN} if it does not.
    *
    * @throws IllegalStateException if this range is unbounded below (that is, {@link
    *     #hasLowerBound()} returns {@code false})
    */
   public BoundType lowerBoundType() {
     return lowerBound.typeAsLowerBound();
   }
 
   /**
    * Returns {@code true} if this range has an upper endpoint.
    */
   public boolean hasUpperBound() {
     return upperBound != Cut.aboveAll();
   }
 
   /**
    * Returns the upper endpoint of this range.
    *
    * @throws IllegalStateException if this range is unbounded above (that is, {@link
    *     #hasUpperBound()} returns {@code false})
    */
   public C upperEndpoint() {
     return upperBound.endpoint();
   }
 
   /**
    * Returns the type of this range's upper bound: {@link BoundType#CLOSED} if the range includes
    * its upper endpoint, {@link BoundType#OPEN} if it does not.
    *
    * @throws IllegalStateException if this range is unbounded above (that is, {@link
    *     #hasUpperBound()} returns {@code false})
    */
   public BoundType upperBoundType() {
     return upperBound.typeAsUpperBound();
   }
 
   /**
    * Returns {@code true} if this range is of the form {@code [v..v)} or {@code (v..v]}. (This does
    * not encompass ranges of the form {@code (v..v)}, because such ranges are <i>invalid</i> and
    * can't be constructed at all.)
    *
    * <p>Note that certain discrete ranges such as the integer range {@code (3..4)} are <b>not</b>
    * considered empty, even though they contain no actual values.  In these cases, it may be
    * helpful to preprocess ranges with {@link #canonical(DiscreteDomain)}.
    */
   public boolean isEmpty() {
     return lowerBound.equals(upperBound);
   }
 
   /**
    * Returns {@code true} if {@code value} is within the bounds of this range. For example, on the
    * range {@code [0..2)}, {@code contains(1)} returns {@code true}, while {@code contains(2)}
    * returns {@code false}.
    */
   public boolean contains(C value) {
     checkNotNull(value);
     // let this throw CCE if there is some trickery going on
     return lowerBound.isLessThan(value) && !upperBound.isLessThan(value);
   }
 
   /**
    * @deprecated Provided only to satisfy the {@link Predicate} interface; use {@link #contains}
    *     instead.
    */
   @Deprecated
   @Override
   public boolean apply(C input) {
     return contains(input);
   }
 
   /**
    * Returns {@code true} if every element in {@code values} is {@linkplain #contains contained} in
    * this range.
    */
   public boolean containsAll(Iterable<? extends C> values) {
     if (Iterables.isEmpty(values)) {
       return true;
     }
 
     // this optimizes testing equality of two range-backed sets
     if (values instanceof SortedSet) {
       SortedSet<? extends C> set = cast(values);
       Comparator<?> comparator = set.comparator();
       if (Ordering.natural().equals(comparator) || comparator == null) {
         return contains(set.first()) && contains(set.last());
       }
     }
 
     for (C value : values) {
       if (!contains(value)) {
         return false;
       }
     }
     return true;
   }
 
   /**
    * Returns {@code true} if the bounds of {@code other} do not extend outside the bounds of this
    * range. Examples:
    *
    * <ul>
    * <li>{@code [3..6]} encloses {@code [4..5]}
    * <li>{@code (3..6)} encloses {@code (3..6)}
    * <li>{@code [3..6]} encloses {@code [4..4)} (even though the latter is empty)
    * <li>{@code (3..6]} does not enclose {@code [3..6]}
    * <li>{@code [4..5]} does not enclose {@code (3..6)} (even though it contains every value
    *     contained by the latter range)
    * <li>{@code [3..6]} does not enclose {@code (1..1]} (even though it contains every value
    *     contained by the latter range)
    * </ul>
    *
    * <p>Note that if {@code a.encloses(b)}, then {@code b.contains(v)} implies
    * {@code a.contains(v)}, but as the last two examples illustrate, the converse is not always
    * true.
    *
    * <p>Being reflexive, antisymmetric and transitive, the {@code encloses} relation defines a
    * <i>partial order</i> over ranges. There exists a unique {@linkplain Range#all maximal} range
    * according to this relation, and also numerous {@linkplain #isEmpty minimal} ranges. Enclosure
    * also implies {@linkplain #isConnected connectedness}.
    */
   public boolean encloses(Range<C> other) {
     return lowerBound.compareTo(other.lowerBound) <= 0
         && upperBound.compareTo(other.upperBound) >= 0;
   }
 
   /**
    * Returns {@code true} if there exists a (possibly empty) range which is {@linkplain #encloses
    * enclosed} by both this range and {@code other}.
    *
    * <p>For example,
    * <ul>
    * <li>{@code [2, 4)} and {@code [5, 7)} are not connected
    * <li>{@code [2, 4)} and {@code [3, 5)} are connected, because both enclose {@code [3, 4)}
    * <li>{@code [2, 4)} and {@code [4, 6)} are connected, because both enclose the empty range
    *     {@code [4, 4)}
    * </ul>
    *
    * <p>Note that this range and {@code other} have a well-defined {@linkplain #span union} and
    * {@linkplain #intersection intersection} (as a single, possibly-empty range) if and only if this
    * method returns {@code true}.
    *
    * <p>The connectedness relation is both reflexive and symmetric, but does not form an {@linkplain
    * Equivalence equivalence relation} as it is not transitive.
    *
    * <p>Note that certain discrete ranges are not considered connected, even though there are no
    * elements "between them."  For example, {@code [3, 5]} is not considered connected to {@code
    * [6, 10]}.  In these cases, it may be desirable for both input ranges to be preprocessed with
    * {@link #canonical(DiscreteDomain)} before testing for connectedness.
    */
   public boolean isConnected(Range<C> other) {
     return lowerBound.compareTo(other.upperBound) <= 0
         && other.lowerBound.compareTo(upperBound) <= 0;
   }
 
   /**
    * Returns the maximal range {@linkplain #encloses enclosed} by both this range and {@code
    * connectedRange}, if such a range exists.
    *
    * <p>For example, the intersection of {@code [1..5]} and {@code (3..7)} is {@code (3..5]}. The
    * resulting range may be empty; for example, {@code [1..5)} intersected with {@code [5..7)}
    * yields the empty range {@code [5..5)}.
    *
    * <p>The intersection exists if and only if the two ranges are {@linkplain #isConnected
    * connected}.
    *
    * <p>The intersection operation is commutative, associative and idempotent, and its identity
    * element is {@link Range#all}).
    *
    * @throws IllegalArgumentException if {@code isConnected(connectedRange)} is {@code false}
    */
   public Range<C> intersection(Range<C> connectedRange) {
     int lowerCmp = lowerBound.compareTo(connectedRange.lowerBound);
     int upperCmp = upperBound.compareTo(connectedRange.upperBound);
     if (lowerCmp >= 0 && upperCmp <= 0) {
       return this;
     } else if (lowerCmp <= 0 && upperCmp >= 0) {
       return connectedRange;
     } else {
       Cut<C> newLower = (lowerCmp >= 0) ? lowerBound : connectedRange.lowerBound;
       Cut<C> newUpper = (upperCmp <= 0) ? upperBound : connectedRange.upperBound;
       return create(newLower, newUpper);
     }
   }
 
   /**
    * Returns the minimal range that {@linkplain #encloses encloses} both this range and {@code
    * other}. For example, the span of {@code [1..3]} and {@code (5..7)} is {@code [1..7)}.
    *
    * <p><i>If</i> the input ranges are {@linkplain #isConnected connected}, the returned range can
    * also be called their <i>union</i>. If they are not, note that the span might contain values
    * that are not contained in either input range.
    *
    * <p>Like {@link #intersection(Range) intersection}, this operation is commutative, associative
    * and idempotent. Unlike it, it is always well-defined for any two input ranges.
    */
   public Range<C> span(Range<C> other) {
     int lowerCmp = lowerBound.compareTo(other.lowerBound);
     int upperCmp = upperBound.compareTo(other.upperBound);
     if (lowerCmp <= 0 && upperCmp >= 0) {
       return this;
     } else if (lowerCmp >= 0 && upperCmp <= 0) {
       return other;
     } else {
       Cut<C> newLower = (lowerCmp <= 0) ? lowerBound : other.lowerBound;
       Cut<C> newUpper = (upperCmp >= 0) ? upperBound : other.upperBound;
       return create(newLower, newUpper);
     }
   }
 
   /**
    * Returns the canonical form of this range in the given domain. The canonical form has the
    * following properties:
    *
    * <ul>
    * <li>equivalence: {@code a.canonical().contains(v) == a.contains(v)} for all {@code v} (in other
    *     words, {@code ContiguousSet.create(a.canonical(domain), domain).equals(
    *     ContiguousSet.create(a, domain))}
    * <li>uniqueness: unless {@code a.isEmpty()},
    *     {@code ContiguousSet.create(a, domain).equals(ContiguousSet.create(b, domain))} implies
    *     {@code a.canonical(domain).equals(b.canonical(domain))}
    * <li>idempotence: {@code a.canonical(domain).canonical(domain).equals(a.canonical(domain))}
    * </ul>
    *
    * <p>Furthermore, this method guarantees that the range returned will be one of the following
    * canonical forms:
    *
    * <ul>
    * <li>[start..end)
    * <li>[start..+∞)
    * <li>(-∞..end) (only if type {@code C} is unbounded below)
    * <li>(-∞..+∞) (only if type {@code C} is unbounded below)
    * </ul>
    */
   public Range<C> canonical(DiscreteDomain<C> domain) {
     checkNotNull(domain);
     Cut<C> lower = lowerBound.canonical(domain);
     Cut<C> upper = upperBound.canonical(domain);
     return (lower == lowerBound && upper == upperBound) ? this : create(lower, upper);
   }
 
   /**
    * Returns {@code true} if {@code object} is a range having the same endpoints and bound types as
    * this range. Note that discrete ranges such as {@code (1..4)} and {@code [2..3]} are <b>not</b>
    * equal to one another, despite the fact that they each contain precisely the same set of values.
    * Similarly, empty ranges are not equal unless they have exactly the same representation, so
    * {@code [3..3)}, {@code (3..3]}, {@code (4..4]} are all unequal.
    */
   @Override public boolean equals(@Nullable Object object) {
     if (object instanceof Range) {
       Range<?> other = (Range<?>) object;
       return lowerBound.equals(other.lowerBound)
           && upperBound.equals(other.upperBound);
     }
     return false;
   }
 
   /** Returns a hash code for this range. */
   @Override public int hashCode() {
     return lowerBound.hashCode() * 31 + upperBound.hashCode();
   }
 
   /**
    * Returns a string representation of this range, such as {@code "[3..5)"} (other examples are
    * listed in the class documentation).
    */
   @Override public String toString() {
     return toString(lowerBound, upperBound);
   }
 
   private static String toString(Cut<?> lowerBound, Cut<?> upperBound) {
     StringBuilder sb = new StringBuilder(16);
     lowerBound.describeAsLowerBound(sb);
     sb.append('\u2025');
     upperBound.describeAsUpperBound(sb);
     return sb.toString();
   }
 
   /**
    * Used to avoid http://bugs.sun.com/view_bug.do?bug_id=6558557
    */
   private static <T> SortedSet<T> cast(Iterable<T> iterable) {
     return (SortedSet<T>) iterable;
   }
 
   Object readResolve() {
     if (this.equals(ALL)) {
       return all();
     } else {
       return this;
     }
   }
 
   @SuppressWarnings("unchecked") // this method may throw CCE
   static int compareOrThrow(Comparable left, Comparable right) {
     return left.compareTo(right);
   }
 
   private static final long serialVersionUID = 0;
 }