Hello, Happy to see someone remembered my work ;o). Actually, I think the use of a parser and a lexer will give HSQLDB a more stable core (if it is well used of course) without talking of the speed improvements.
>From my point of view, JFlex is very simple to use and very fast. After that, I would prefer to use JavaCC and at last antlr. Note that JFlex works pretty well with CUP (http://www.cs.princeton.edu/~appel/modern/java/CUP/) and that the syntax of JFlex looks like Lex's one as the syntax of CUP looks like Yacc's one. About the licenses, well how about to contact the authors. Loic Internet [EMAIL PROTECTED]@lists.sourceforge.net - 23/07/2004 12:15 Envoyé par : [EMAIL PROTECTED] Pour : hsqldb-developers cc : Objet : [Hsqldb-developers] Stored Procedures - new Lexer and Parser Since the beginning of the project, there have been regular requests for support for conventional stored procedures (and triggers). This was always postponed to some unspecified time in the future as a proper implementation would ideally involve a rewrite of the parser and command executor parts of the engine. Recently Liuxin, a CS researcher, has asked to join us and work on this. I would like to welcome Liuxin and start the ball rolling. My proposed plan is to develop a new set of classes for the functionality that is currently in Tokenizer, Parser, and Expression. A grammar based approach will be taken, using JavaCC, JFlex or Antler based on our requirements and modified if necessary. Our initial objective would be a working implementation with a minimum set of procedural features (conditions, loops, variables) plus the existing level of SQL support. The procedural language should be a subset of SQL standard Part4 (SQL/PSM). I will coordinate this effort overall and ensure the integration of the resulting data structures into the engine. Developers are invited to join the effort and contribute. Some areas of work are: - assessment of JavaCC and Antler in terms of speed and capability - the licenses for these programs are compatible with ours and we can modify and incorporate them. Compare to JFlex for lexer speed (very important factor in our choice). An experimental lexer developed last year by Loic with JFlex seemed pretty fast and comparative tests reported recently on the JFlex mailing list showed it was much faster than Antler in tokenizing. - any modifications to the lexer / parser as necessary - work on grammar - help with integration (for developers who have already worked on the core) - help with tests Comments are welcome. Fred Toussi ------------------------------------------------------- This SF.Net email is sponsored by BEA Weblogic Workshop FREE Java Enterprise J2EE developer tools! Get your free copy of BEA WebLogic Workshop 8.1 today. http://ads.osdn.com/?ad_id=4721&alloc_id=10040&op=click _______________________________________________ hsqldb-developers mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/hsqldb-developers This message and any attachments (the "message") is intended solely for the addressees and is confidential. If you receive this message in error, please delete it and immediately notify the sender. Any use not in accord with its purpose, any dissemination or disclosure, either whole or partial, is prohibited except formal approval. The internet can not guarantee the integrity of this message. BNP PARIBAS (and its subsidiaries) shall (will) not therefore be liable for the message if modified. --------------------------------------------- Ce message et toutes les pieces jointes (ci-apres le "message") sont etablis a l'intention exclusive de ses destinataires et sont confidentiels. Si vous recevez ce message par erreur, merci de le detruire et d'en avertir immediatement l'expediteur. Toute utilisation de ce message non conforme a sa destination, toute diffusion ou toute publication, totale ou partielle, est interdite, sauf autorisation expresse. L'internet ne permettant pas d'assurer l'integrite de ce message, BNP PARIBAS (et ses filiales) decline(nt) toute responsabilite au titre de ce message, dans l'hypothese ou il aurait ete modifie. ------------------------------------------------------- This SF.Net email is sponsored by BEA Weblogic Workshop FREE Java Enterprise J2EE developer tools! Get your free copy of BEA WebLogic Workshop 8.1 today. http://ads.osdn.com/?ad_idG21&alloc_id040&op=click _______________________________________________ hsqldb-developers mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/hsqldb-developers
