Path: csiph.com!3.us.feeder.erje.net!feeder.erje.net!news.linkpendium.com!news.linkpendium.com!news.snarked.org!border2.nntp.dca1.giganews.com!nntp.giganews.com!news.iecc.com!.POSTED.news.iecc.com!nerds-end From: Andy Newsgroups: comp.compilers Subject: FIRST_k, FOLLOW_k, k>1 Date: Thu, 6 Feb 2020 10:43:24 -0800 (PST) Organization: Compilers Central Lines: 15 Sender: news@iecc.com Approved: comp.compilers@iecc.com Message-ID: <20-02-004@comp.compilers> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Injection-Info: gal.iecc.com; posting-host="news.iecc.com:2001:470:1f07:1126:0:676f:7373:6970"; logging-data="48592"; mail-complaints-to="abuse@iecc.com" Keywords: parse, question Posted-Date: 06 Feb 2020 14:17:10 EST X-submission-address: compilers@iecc.com X-moderator-address: compilers-request@iecc.com X-FAQ-and-archives: http://compilers.iecc.com Xref: csiph.com comp.compilers:2442 If LL(l) and LR(k) need sets FIRST_k, FOLLOW_k, k>1, for example LR(3) need this sets of degree 3? How make it? How is the best structure for these sets? I think about pyramid: - one bit - is epsilon - bit table size n - bit table size n^2 ... - bit table size n^k because sets degree of k also have shorter strings. This exponentially grows, in real grammars, number of tokens can be quite big, ~80, It need then 0(80^k) bits. This sets will sparse and is better organization of substrings in sets? For example, not bit set but set of trees or DFA's ?