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- package java.lang;
- /*
- * Copyright (c) 1997, 2007, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation. Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
- /**
- * This interface imposes a total ordering on the objects of each class that
- * implements it. This ordering is referred to as the class's <i>natural
- * ordering</i>, and the class's <tt>compareTo</tt> method is referred to as
- * its <i>natural comparison method</i>.<p>
- *
- * Lists (and arrays) of objects that implement this interface can be sorted
- * automatically by {@link Collections#sort(List) Collections.sort} (and
- * {@link Arrays#sort(Object[]) Arrays.sort}). Objects that implement this
- * interface can be used as keys in a {@linkplain SortedMap sorted map} or as
- * elements in a {@linkplain SortedSet sorted set}, without the need to
- * specify a {@linkplain Comparator comparator}.<p>
- *
- * The natural ordering for a class <tt>C</tt> is said to be <i>consistent
- * with equals</i> if and only if <tt>e1.compareTo(e2) == 0</tt> has
- * the same boolean value as <tt>e1.equals(e2)</tt> for every
- * <tt>e1</tt> and <tt>e2</tt> of class <tt>C</tt>. Note that <tt>null</tt>
- * is not an instance of any class, and <tt>e.compareTo(null)</tt> should
- * throw a <tt>NullPointerException</tt> even though <tt>e.equals(null)</tt>
- * returns <tt>false</tt>.<p>
- *
- * It is strongly recommended (though not required) that natural orderings be
- * consistent with equals. This is so because sorted sets (and sorted maps)
- * without explicit comparators behave "strangely" when they are used with
- * elements (or keys) whose natural ordering is inconsistent with equals. In
- * particular, such a sorted set (or sorted map) violates the general contract
- * for set (or map), which is defined in terms of the <tt>equals</tt>
- * method.<p>
- *
- * For example, if one adds two keys <tt>a</tt> and <tt>b</tt> such that
- * <tt>(!a.equals(b) && a.compareTo(b) == 0)</tt> to a sorted
- * set that does not use an explicit comparator, the second <tt>add</tt>
- * operation returns false (and the size of the sorted set does not increase)
- * because <tt>a</tt> and <tt>b</tt> are equivalent from the sorted set's
- * perspective.<p>
- *
- * Virtually all Java core classes that implement <tt>Comparable</tt> have natural
- * orderings that are consistent with equals. One exception is
- * <tt>java.math.BigDecimal</tt>, whose natural ordering equates
- * <tt>BigDecimal</tt> objects with equal values and different precisions
- * (such as 4.0 and 4.00).<p>
- *
- * For the mathematically inclined, the <i>relation</i> that defines
- * the natural ordering on a given class C is:<pre>
- * {(x, y) such that x.compareTo(y) <= 0}.
- * </pre> The <i>quotient</i> for this total order is: <pre>
- * {(x, y) such that x.compareTo(y) == 0}.
- * </pre>
- *
- * It follows immediately from the contract for <tt>compareTo</tt> that the
- * quotient is an <i>equivalence relation</i> on <tt>C</tt>, and that the
- * natural ordering is a <i>total order</i> on <tt>C</tt>. When we say that a
- * class's natural ordering is <i>consistent with equals</i>, we mean that the
- * quotient for the natural ordering is the equivalence relation defined by
- * the class's {@link Object#equals(Object) equals(Object)} method:<pre>
- * {(x, y) such that x.equals(y)}. </pre><p>
- *
- * This interface is a member of the
- * <a href="{@docRoot}/../technotes/guides/collections/index.html">
- * Java Collections Framework</a>.
- *
- * @param <T> the type of objects that this object may be compared to
- *
- * @author Josh Bloch
- * @see java.util.Comparator
- * @since 1.2
- */
- @:require(java2) extern interface Comparable<T>
- {
- /**
- * Compares this object with the specified object for order. Returns a
- * negative integer, zero, or a positive integer as this object is less
- * than, equal to, or greater than the specified object.
- *
- * <p>The implementor must ensure <tt>sgn(x.compareTo(y)) ==
- * -sgn(y.compareTo(x))</tt> for all <tt>x</tt> and <tt>y</tt>. (This
- * implies that <tt>x.compareTo(y)</tt> must throw an exception iff
- * <tt>y.compareTo(x)</tt> throws an exception.)
- *
- * <p>The implementor must also ensure that the relation is transitive:
- * <tt>(x.compareTo(y)>0 && y.compareTo(z)>0)</tt> implies
- * <tt>x.compareTo(z)>0</tt>.
- *
- * <p>Finally, the implementor must ensure that <tt>x.compareTo(y)==0</tt>
- * implies that <tt>sgn(x.compareTo(z)) == sgn(y.compareTo(z))</tt>, for
- * all <tt>z</tt>.
- *
- * <p>It is strongly recommended, but <i>not</i> strictly required that
- * <tt>(x.compareTo(y)==0) == (x.equals(y))</tt>. Generally speaking, any
- * class that implements the <tt>Comparable</tt> interface and violates
- * this condition should clearly indicate this fact. The recommended
- * language is "Note: this class has a natural ordering that is
- * inconsistent with equals."
- *
- * <p>In the foregoing description, the notation
- * <tt>sgn(</tt><i>expression</i><tt>)</tt> designates the mathematical
- * <i>signum</i> function, which is defined to return one of <tt>-1</tt>,
- * <tt>0</tt>, or <tt>1</tt> according to whether the value of
- * <i>expression</i> is negative, zero or positive.
- *
- * @param o the object to be compared.
- * @return a negative integer, zero, or a positive integer as this object
- * is less than, equal to, or greater than the specified object.
- *
- * @throws NullPointerException if the specified object is null
- * @throws ClassCastException if the specified object's type prevents it
- * from being compared to this object.
- */
- @:overload public function compareTo(o : T) : Int;
-
-
- }
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