BSP: A Parsing Tool for Ambiguous Regular Expressions

  • Angelo Borsotti
  • Luca Breveglieri
  • Stefano Crespi ReghizziEmail author
  • Angelo Morzenti
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 9223)


BSP (Berry-Sethi Parser) is a new SW tool for parsing ambiguous regular expressions (r.e.). Given a r.e., the BSP tool generates a DFA. Then the DFA processes the given input string, recognizes it and outputs, depending on user choice, all the syntax trees or just the one selected by either the Greedy or the POSIX criterion. The BSP tool is a HTML page including JavaScript code, and can be executed by any browser. It is self-documented and is intended for educational purposes. See (see also [1] for details).


Regular Expression Parse Tree Input String Syntax Tree Abstract Syntax Tree 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. 1.
    Borsotti, A., Breveglieri, L., Crespi Reghizzi, S., Morzenti, A.: From ambiguous regular expressions to deterministic parsing automata. In: Drewes, F. (ed.) CIAA. LNCS, vol. 9223, pp. 35–48. Springer, Heidelberg (2015)Google Scholar
  2. 2.
    Frisch, A., Cardelli, L.: Greedy regular expression matching. In: Díaz, J., Karhumäki, J., Lepistö, A., Sannella, D. (eds.) ICALP 2004. LNCS, vol. 3142, pp. 618–629. Springer, Heidelberg (2004) Google Scholar
  3. 3.
    IEEE: std. 1003.2, POSIX, regular expression notation, section 2.8 (1992)Google Scholar
  4. 4.
    Okui, S., Suzuki, T.: Disambiguation in regular expression matching via position automata with augmented transitions. In: Domaratzki, M., Salomaa, K. (eds.) CIAA 2010. LNCS, vol. 6482, pp. 231–240. Springer, Heidelberg (2011) Google Scholar

Copyright information

© Springer International Publishing Switzerland 2015

Authors and Affiliations

  • Angelo Borsotti
    • 1
  • Luca Breveglieri
    • 1
  • Stefano Crespi Reghizzi
    • 2
    Email author
  • Angelo Morzenti
    • 1
  1. 1.Dipartimento di Elettronica, Informazione E Bioingegneria (DEIB)Politecnico di MilanoMilanoItaly
  2. 2.Dipartimento di Elettronica, Informazione E Bioingegneria (DEIB)CNR - IEIIT, Politecnico di MilanoMilanoItaly

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