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29 * Marker interface used by <tt>List</tt> implementations to indicate that
30 * they support fast (generally constant time) random access. The primary
31 * purpose of this interface is to allow generic algorithms to alter their
32 * behavior to provide good performance when applied to either random or
33 * sequential access lists.
35 * <p>The best algorithms for manipulating random access lists (such as
36 * <tt>ArrayList</tt>) can produce quadratic behavior when applied to
37 * sequential access lists (such as <tt>LinkedList</tt>). Generic list
38 * algorithms are encouraged to check whether the given list is an
39 * <tt>instanceof</tt> this interface before applying an algorithm that would
40 * provide poor performance if it were applied to a sequential access list,
41 * and to alter their behavior if necessary to guarantee acceptable
44 * <p>It is recognized that the distinction between random and sequential
45 * access is often fuzzy. For example, some <tt>List</tt> implementations
46 * provide asymptotically linear access times if they get huge, but constant
47 * access times in practice. Such a <tt>List</tt> implementation
48 * should generally implement this interface. As a rule of thumb, a
49 * <tt>List</tt> implementation should implement this interface if,
50 * for typical instances of the class, this loop:
52 * for (int i=0, n=list.size(); i < n; i++)
55 * runs faster than this loop:
57 * for (Iterator i=list.iterator(); i.hasNext(); )
61 * <p>This interface is a member of the
62 * <a href="{@docRoot}/../technotes/guides/collections/index.html">
63 * Java Collections Framework</a>.
67 public interface RandomAccess {