Accessing the Internal Organization of Data Structures in the JDSL Library

Abstract

Many applications require data structures that allow efficient access to their internal organization and to their elements. This feature has been implemented in some libraries with iterators or items. We present an alternative implementation, used in the Library of Data Structures for Java (JDSL). We refine the notion of an item and split it into two related concepts: position and locator. Positions are an abstraction of a pointer to a node or an index into an array; they provide direct access to the in-memory structure of the container. Locators add a level of indirection and allow the user to find a specific element even if the position holding the element changes.