@InProceedings{peterfreund_et_al:LIPIcs.ICDT.2019.13, author = {Peterfreund, Liat and Cate, Balder ten and Fagin, Ronald and Kimelfeld, Benny}, title = {{Recursive Programs for Document Spanners}}, booktitle = {22nd International Conference on Database Theory (ICDT 2019)}, pages = {13:1--13:18}, series = {Leibniz International Proceedings in Informatics (LIPIcs)}, ISBN = {978-3-95977-101-6}, ISSN = {1868-8969}, year = {2019}, volume = {127}, editor = {Barcelo, Pablo and Calautti, Marco}, publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik}, address = {Dagstuhl, Germany}, URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ICDT.2019.13}, URN = {urn:nbn:de:0030-drops-103155}, doi = {10.4230/LIPIcs.ICDT.2019.13}, annote = {Keywords: Information Extraction, Document Spanners, Polynomial Time, Recursion, Regular Expressions, Datalog} }