Re: FIRST_k, FOLLOW_k, k>1

Hans-Peter Diettrich <DrDiettrich1@netscape.net>
Sun, 9 Feb 2020 02:46:22 +0100

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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: Hans-Peter Diettrich <DrDiettrich1@netscape.net>
Newsgroups: comp.compilers
Date: Sun, 9 Feb 2020 02:46:22 +0100
Organization: Compilers Central
References: 20-02-004 20-02-005 20-02-007 20-02-008
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Keywords: parse
Posted-Date: 08 Feb 2020 20:51:49 EST

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


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