Take a look at incubator/orxutils/ocube. The ocube program contains a parser written in ooRexx to parse the grammar for the implementation of ocube. The grammer for ocube is a simplified version of the Rexx grammer so you might be able to use it as a base for your work. The code was written some years ago for IBM Object Rexx (like around 2001) so there are real possibilities for areas of improvement.
Good luck. David Ashley On 04/23/2010 03:02 AM, Moritz Hoffmann wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Hi, > > I'm currently trying to write a grammar for ooRexx to build a workbench > on it. However, I face some problems. > > The grammar requires to be context free, and have no left recursions. > Internally, it will use ANTLR to do the parsing, which is a LR(*). > > First, I face some problem tokenizing the input, but that' snot the > biggest issue yet. I will ask about that again. > > The main issue is to parse expressions. I had a look at the ooRexx > source code to figure out how it does it, but it's complex. > > So, I'm asking for help regarding a single example in ebnf to parse some > expression, including precedence and such. > > The problem that ooRexx uses token sub-types is mostly solved. This is > that words like "if" are keywords at some places and just symbols at > other places. Due to this, all keywords have to be recognized as symbols > as well. > > The grammar that is currently in the SVN, has some bugs - and they're > hard to figure out... > > Kind regards, > Moritz > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.10 (GNU/Linux) > Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ > > iEYEARECAAYFAkvRVBMACgkQl56sB+DIUZQ5PwCeK2X8sQRa25clg/NoJ5tvVfi7 > idoAnj7ccZhysCjTWNCOx/VQdpBztcO5 > =ESBR > -----END PGP SIGNATURE----- > > ------------------------------------------------------------------------------ > _______________________________________________ > Oorexx-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/oorexx-devel > > ------------------------------------------------------------------------------ _______________________________________________ Oorexx-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/oorexx-devel
