1. A computer-implemented system for providing a representation of a subset of items stored within an original data structure, comprising: a computer-readable medium having computer-executable instructions stored thereon, the computer-executable instructions being executed by a processor to implement a virtual item set processor configured to generate a virtual item set containing a plurality of virtual items, wherein the plurality of virtual items includes the subset of items in the original data structure, wherein each virtual item of the plurality of virtual items includes a data field containing a reference to a data item in the original data structure, wherein the reference includes position information representing a position of the data item within the original data structure, and a metadata field, wherein the metadata field contains information regarding characteristics of the data item to which the data field refers; wherein the virtual item set processor is configured to receive a change to the data field, wherein the virtual item set processor is configured to change the data item in response to the received change to the data field, wherein the virtual item set processor is configured to change the data item directly in the original data structure using the reference.