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src/java.base/share/classes/java/util/RandomAccess.java

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*** 24,54 **** */ package java.util; /** ! * Marker interface used by <tt>List</tt> implementations to indicate that * they support fast (generally constant time) random access. The primary * purpose of this interface is to allow generic algorithms to alter their * behavior to provide good performance when applied to either random or * sequential access lists. * * <p>The best algorithms for manipulating random access lists (such as ! * <tt>ArrayList</tt>) can produce quadratic behavior when applied to ! * sequential access lists (such as <tt>LinkedList</tt>). Generic list * algorithms are encouraged to check whether the given list is an ! * <tt>instanceof</tt> this interface before applying an algorithm that would * provide poor performance if it were applied to a sequential access list, * and to alter their behavior if necessary to guarantee acceptable * performance. * * <p>It is recognized that the distinction between random and sequential ! * access is often fuzzy. For example, some <tt>List</tt> implementations * provide asymptotically linear access times if they get huge, but constant ! * access times in practice. Such a <tt>List</tt> implementation * should generally implement this interface. As a rule of thumb, a ! * <tt>List</tt> implementation should implement this interface if, * for typical instances of the class, this loop: * <pre> * for (int i=0, n=list.size(); i &lt; n; i++) * list.get(i); * </pre> --- 24,54 ---- */ package java.util; /** ! * Marker interface used by {@code List} implementations to indicate that * they support fast (generally constant time) random access. The primary * purpose of this interface is to allow generic algorithms to alter their * behavior to provide good performance when applied to either random or * sequential access lists. * * <p>The best algorithms for manipulating random access lists (such as ! * {@code ArrayList}) can produce quadratic behavior when applied to ! * sequential access lists (such as {@code LinkedList}). Generic list * algorithms are encouraged to check whether the given list is an ! * {@code instanceof} this interface before applying an algorithm that would * provide poor performance if it were applied to a sequential access list, * and to alter their behavior if necessary to guarantee acceptable * performance. * * <p>It is recognized that the distinction between random and sequential ! * access is often fuzzy. For example, some {@code List} implementations * provide asymptotically linear access times if they get huge, but constant ! * access times in practice. Such a {@code List} implementation * should generally implement this interface. As a rule of thumb, a ! * {@code List} implementation should implement this interface if, * for typical instances of the class, this loop: * <pre> * for (int i=0, n=list.size(); i &lt; n; i++) * list.get(i); * </pre>
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