The contents of each parse tree node consist of a collection of attribute/value pairs. Internally, the nodes are simply represented by hash tables. A display of -the entire parse-tree structure can be obtained using swig -dump_tree. +the entire parse-tree structure can be obtained using swig -debug-top <n>, where n is +the stage being processed. There are a number of other parse tree display options, for example, swig -debug-module <n> will avoid displaying system parse information and only display the parse tree pertaining to the user's module at stage n of processing.