Path: csiph.com!xmission!news.snarked.org!border2.nntp.dca1.giganews.com!border1.nntp.dca1.giganews.com!nntp.giganews.com!news.iecc.com!.POSTED.news.iecc.com!nerds-end From: Hans-Peter Diettrich Newsgroups: comp.compilers Subject: Re: FIRST_k, FOLLOW_k, k>1 Date: Sun, 9 Feb 2020 02:46:22 +0100 Organization: Compilers Central Lines: 21 Sender: news@iecc.com Approved: comp.compilers@iecc.com Message-ID: <20-02-009@comp.compilers> References: <20-02-004@comp.compilers> <20-02-005@comp.compilers> <20-02-007@comp.compilers> <20-02-008@comp.compilers> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Info: gal.iecc.com; posting-host="news.iecc.com:2001:470:1f07:1126:0:676f:7373:6970"; logging-data="67553"; mail-complaints-to="abuse@iecc.com" Keywords: parse Posted-Date: 08 Feb 2020 20:51:49 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:2447 Am 08.02.2020 um 20:54 schrieb Andy: > W dniu sobota, 8 lutego 2020 15:36:39 UTC+1 użytkownik Hans-Peter Diettrich > napisał: >> IMO the FIRST set covers all *different* sequences, in your case >> FIRST(E)={a} hence LL(1). >> Only if there exist multiple alternatives starting with 'a' they have to >> be listed as e.g. FIRST(E)={ax, ay}. > > Suppose that A is non-starting nonterminal. > FIRST_k(A) is set of token strings lengths 1..k derived from A or derived from > start symbol and begins at A begin? What's the purpose of exploding the FIRST and FOLLOW sets of a LL(1) grammar into something more complicated? IMO you misunderstand the classification of LL grammars and languages :-( DoDi