Re: FIRST_k, FOLLOW_k, k>1

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	Andy <borucki.andrzej@gmail.com>
Newsgroups	comp.compilers
Subject	Re: FIRST_k, FOLLOW_k, k>1
Date	Sat, 8 Feb 2020 11:54:11 -0800 (PST)
Organization	Compilers Central
Lines	15
Sender	news@iecc.com
Approved	comp.compilers@iecc.com
Message-ID	<20-02-008@comp.compilers> (permalink)
References	<20-02-004@comp.compilers> <20-02-005@comp.compilers> <20-02-007@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="73747"; mail-complaints-to="abuse@iecc.com"
Keywords	parse
Posted-Date	08 Feb 2020 15:03:56 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	<20-02-007@comp.compilers>
Xref	csiph.com comp.compilers:2446

Show key headers only | View raw

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?
for example, if we have E->AB, First_4(A) are also strings from B? (if in
First_4(A) exists shorter strings than 4)
It seems that in both situation Follow_4(A) will complicated and contains all
strings from B,C,D... for E->ABCD (if exists in A,B,C shorter stings)

Back to comp.compilers | Previous | Next — Previous in thread | Next in thread | Find similar

Thread

FIRST_k, FOLLOW_k, k>1 Andy <borucki.andrzej@gmail.com> - 2020-02-06 10:43 -0800
  Re: FIRST_k, FOLLOW_k, k>1 Andy <borucki.andrzej@gmail.com> - 2020-02-06 14:16 -0800
    Re: FIRST_k, FOLLOW_k, k>1 Hans-Peter Diettrich <DrDiettrich1@netscape.net> - 2020-02-08 11:00 +0100
      Re: FIRST_k, FOLLOW_k, k>1 Andy <borucki.andrzej@gmail.com> - 2020-02-08 11:54 -0800
        Re: FIRST_k, FOLLOW_k, k>1 Hans-Peter Diettrich <DrDiettrich1@netscape.net> - 2020-02-09 02:46 +0100
  FIRST_k, FOLLOW_k, k&gt;1 Christopher F Clark <christopher.f.clark@compiler-resources.com> - 2020-02-07 16:12 +0200
  Re: FIRST_k, FOLLOW_k, k>1 honey crisis <gaztoast@gmail.com> - 2020-02-08 18:18 -0800

csiph-web