Path: csiph.com!goblin3!goblin.stu.neva.ru!news.misty.com!news.iecc.com!.POSTED.news.iecc.com!nerds-end From: Andy Newsgroups: comp.compilers Subject: Re: FIRST_k, FOLLOW_k, k>1 Date: Thu, 6 Feb 2020 14:16:24 -0800 (PST) Organization: Compilers Central Lines: 42 Sender: news@iecc.com Approved: comp.compilers@iecc.com Message-ID: <20-02-005@comp.compilers> References: <20-02-004@comp.compilers> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Injection-Info: gal.iecc.com; posting-host="news.iecc.com:2001:470:1f07:1126:0:676f:7373:6970"; logging-data="78141"; mail-complaints-to="abuse@iecc.com" Keywords: parse, question Posted-Date: 07 Feb 2020 22:16:30 EST X-submission-address: compilers@iecc.com X-moderator-address: compilers-request@iecc.com X-FAQ-and-archives: http://compilers.iecc.com In-Reply-To: <20-02-004@comp.compilers> Xref: csiph.com comp.compilers:2443 I search examples, E->aWbXYcdZ W->w X->x Y->y Z->z if for FIRST(k=4) wil be: E={awbx} W={wbxy} X={xycd} Y={ycdz} Z={z} what is convention? E is obviously {awbx} but W is (difficult){wbxy} or only {w}? FIRST(k=4)(W) we compute for alone W or W in context whole E? similar: E->aWbXYcdZ W->w X->x Y->y Y-> Z->z ;y->epsilon will? FIRST3: E={awb} W={wbx} X={xyc xcd} Y={ycd cdz} Z={z} ;dotyczy też X FIRST4: E={awbx} W={wbxy wbxc} X={xycd xcdz} Y={ycdz cdz} Z={z} E->aWbXYcdZ >E->X W->w X->x Y->y Y-> Z->z will? FIRST1: E={a x} W={w} X={x} Y={y c} Z={z} FIRST2: E={aw x} W={wb} X={xy xc x} Y={yc cd} Z={z} FIRST3: E={awb x} W={wbx} X={xyc xcd x} Y={ycd cdz} Z={z} FIRST4: E={awbx x} W={wbxy wbxc} X={xycd xcdz x} Y={ycdz cdz} Z={z} FOLLOW1: E={$} W={b} X={y c $} Y={c} Z={$} FOLLOW2: E={$} W={bx} X={yc cd $} Y={cd} Z={$} FOLLOW3: E={$} W={bxy bxc} X={ycd cdz $} Y={cdz} Z={$} FOLLOW4: E={$} W={bxyc bxcd} X={ycdz cdz $} Y={cdz} Z={$} etc