On 04/01/2012 15:37, Seref Arikan wrote: > 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.
there is no guarantee that the current grammar is the best one, and in my view, a better grammar could be developed. We just need to make sure it deals with the typical queries we write, and ones that are already written (or at least that the latter could safely be translated). Other thing to keep in mind: many non-LL grammars are probably computable as LL grammars with sufficient tokens of lookahead. - thomas
