A computer-implemented method to access a data structure including a tree data structure in a computing environment. The method includes generating the data structure in the computing environment. The tree data structure includes a plurality of nodes, a node in the plurality of nodes embodying a plurality of fields, and at least one child link and at least one next link, the at least one child link and the at least one next link being used to link two or more nodes in the plurality of nodes. The method further includes accessing contents of the data structure with an access command in the computing environment. The access command includes a reference to at least one node of the tree data structure and a user-defined argument.