Abstract
We study the usage of negation in JSON Schema data modeling. Negation is a logical operator rarely present in type systems and schema description languages, since it complicates decision problems: many software tools, but also formal frameworks for working with JSON Schema, do not fully support negation. This motivates us to study whether negation is actually used in practice, for which aims, and whether it could—in principle—be replaced by simpler operators. We have collected a large corpus of 80k open source JSON Schema documents from GitHub. We perform a systematic analysis, quantify usage patterns of negation, and also qualitatively analyze schemas. We show that negation is indeed used, albeit infrequently, following a stable set of patterns.
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Notes
- 1.
SchemaStore, at https://www.schemastore.org/json/, last accessed 21-Apr-2021.
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Acknowledgments
This contribution was partly funded by Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) grant #385808805. The schemas were retrieved using Google BigQuery, supported by Google Cloud. We thank Thomas Pilz (OTH Regensburg) for his help in making the research artifacts available. We thank Michael Fruth (University of Passau) for feedback on an earlier draft.
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Baazizi, MA., Colazzo, D., Ghelli, G., Sartiani, C., Scherzinger, S. (2021). An Empirical Study on the “Usage of Not” in Real-World JSON Schema Documents. In: Ghose, A., Horkoff, J., Silva Souza, V.E., Parsons, J., Evermann, J. (eds) Conceptual Modeling. ER 2021. Lecture Notes in Computer Science(), vol 13011. Springer, Cham. https://doi.org/10.1007/978-3-030-89022-3_9
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