Corresponding to the variety of notions of asymmetric lens, various notions of symmetric lens have been proposed. A common theory of the various asymmetric and symmetric lenses should result from a study of spans of asymmetric lenses. In order to define a category whose arrows are spans of asymmetric lenses, the fact that a cospan of asymmetric lenses may not have a pullback must be dealt with. In this article, after resolving that problem we develop the functors which exhibit a category whose arrows are spans of wellbehaved lenses as a retract of a category whose arrows are the corresponding symmetric lenses. We relate them to the symmetric lenses of Hofmann, Pierce and Wagner.
|Number of pages||7|
|Journal||CEUR Workshop Proceedings|
|Publication status||Published - 2014|
|Event||Joint Workshops on International Conference on Extending Database Technology (EDBT 2014) and International Conference on Database Theory (ICDT 2014) - Athens, Greece|
Duration: 28 Mar 2014 → 28 Mar 2014