Hi Seref, My ADL parser does not include AQL parsing. I used Treetop, which is an Ruby implementation of PEG/Packrat parsing algorithm, not LL/LR. PEG/Packrat parser algorithm was described in this paper. http://bford.info/pub/lang/packrat-icfp02/
Antlr is an implementation of PEG parser by LL techniques. I do not know Antlr so much. Packrat parser does not need to separate scanner/parser/lexer and is capable to infinite look ahead recursive. I do not know why are you parsing AQL, but this proceeding about querying EHR by archetype might be helpful for your research. http://web-ext.u-aizu.ac.jp/labs/sw-db/7108/71080109.pdf Best regards, Shinji 2012/1/5 Seref Arikan <serefarikan at kurumsalteknoloji.com>: > Greetings, > The AQL grammar from the wiki has direct and indirect left recursion. Which > means without changes in the grammar, LL parser generators (both JavaCC and > Anltr) can't generate parsers for this grammar. > > I'm curious if anybody has refactored this grammar for LL parser generators. > Shinji? Your latest release includes an AQL parser does not it? Could you > please share your method? I can always look at the code, but you'd probably > save me time :) > > I'm interested in experiences of others too. > > > Kind regards > Seref > > > _______________________________________________ > openEHR-technical mailing list > openEHR-technical at openehr.org > http://lists.chime.ucl.ac.uk/mailman/listinfo/openehr-technical >
