Re: FIRST_k, FOLLOW_k, k>1

Andy <borucki.andrzej@gmail.com>
Sat, 8 Feb 2020 11:54:11 -0800 (PST)

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Related articles
FIRST_k, FOLLOW_k, k>1 borucki.andrzej@gmail.com (Andy) (2020-02-06)
Re: FIRST_k, FOLLOW_k, k>1 borucki.andrzej@gmail.com (Andy) (2020-02-06)
Re: FIRST_k, FOLLOW_k, k>1 DrDiettrich1@netscape.net (Hans-Peter Diettrich) (2020-02-08)
Re: FIRST_k, FOLLOW_k, k>1 borucki.andrzej@gmail.com (Andy) (2020-02-08)
Re: FIRST_k, FOLLOW_k, k>1 DrDiettrich1@netscape.net (Hans-Peter Diettrich) (2020-02-09)
Re: FIRST_k, FOLLOW_k, k>1 gaztoast@gmail.com (honey crisis) (2020-02-08)
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From: Andy <borucki.andrzej@gmail.com>
Newsgroups: comp.compilers
Date: Sat, 8 Feb 2020 11:54:11 -0800 (PST)
Organization: Compilers Central
References: 20-02-004 20-02-005 20-02-007
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Keywords: parse
Posted-Date: 08 Feb 2020 15:03:56 EST
In-Reply-To: 20-02-007

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)


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