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Re: LR(1) Parsing : Error Handling & Recovery

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From Chris Dodd <cdodd@acm.org>
Newsgroups comp.compilers
Subject Re: LR(1) Parsing : Error Handling & Recovery
Date Tue, 29 Jul 2014 19:38:48 +0000 (UTC)
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Hans-Peter Diettrich <DrDiettrich1@netscape.net> wrote in
> Unfortunately I couldn't get the article, so here's what I don't understand:
>
>> is:
>>
>>     S ::= aSA | \epsilon
>>     A ::= aabS | c
>>
>> This grammar (and the language) is LL(2), but there does not exist an
>> equivalent LL(1) grammar.
>
> IMO this grammar is LL(3), not LL(2). There might be a typo in A, which
> might originally read as:
>    A ::= abS | c
> resulting in an LL(2) grammar.

Yes, my fault for not carefully checking my post.  As written, it's an
LL(3) grammar for a language that is not LL(2).  Remove one 'a' from
the 'A' rule to get an LL(2) grammar for a language that is not LL(1).
Add 'a's to get an LL(k) grammar for a language that is not LL(k-1)
for any k...

Chris Dodd
cdodd@acm.org

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Thread

LR(1) Parsing : Error Handling & Recovery Seima Rao <seimarao@gmail.com> - 2014-07-10 05:30 +0530
  Re: LR(1) Parsing : Error Handling & Recovery Ivan Godard <ivan@ootbcomp.com> - 2014-07-16 16:39 -0400
    Re: LR(1) Parsing : Error Handling & Recovery Evangelos Drikos <drikosev@otenet.gr> - 2014-07-17 20:15 +0300
      Re: LR(1) Parsing : Error Handling & Recovery Ivan Godard <ivan@ootbcomp.com> - 2014-07-17 13:03 -0700
        Re: LR(1) Parsing : Error Handling & Recovery Ivan Godard <ivan@ootbcomp.com> - 2014-07-17 13:57 -0700
          Re: LR(1) Parsing : Error Handling & Recovery wclodius@earthlink.net (William Clodius) - 2014-07-18 13:41 -0600
            Re: LR(1) Parsing : Error Handling & Recovery Stefan Monnier <monnier@iro.umontreal.ca> - 2014-07-18 21:09 -0400
              Re: LR(1) Parsing : Error Handling & Recovery Hans-Peter Diettrich <DrDiettrich1@aol.com> - 2014-07-19 12:04 +0200
                Re: LR(1) Parsing : Error Handling & Recovery Stefan Monnier <monnier@iro.umontreal.ca> - 2014-07-20 10:28 -0400
                Re: LR(1) Parsing : Error Handling & Recovery Hans-Peter Diettrich <DrDiettrich1@netscape.net> - 2014-07-21 10:46 +0200
                Re: LR(1) Parsing : Error Handling & Recovery Stefan Monnier <monnier@iro.umontreal.ca> - 2014-08-06 21:32 -0400
            Re: LR(1) Parsing : Error Handling & Recovery arnold@skeeve.com (Aharon Robbins) - 2014-07-20 06:05 +0000
    Re: LR(1) Parsing : Error Handling & Recovery George Neuner <gneuner2@comcast.net> - 2014-07-17 18:49 -0400
      Re: LR(1) Parsing : Error Handling & Recovery wclodius@earthlink.net (William Clodius) - 2014-07-18 13:41 -0600
        Re: LR(1) Parsing : Error Handling & Recovery Hans Aberg <haberg-news@telia.com> - 2014-07-19 15:29 +0200
          Re: LR(1) Parsing : Error Handling & Recovery Evangelos Drikos <drikosev@otenet.gr> - 2014-07-20 00:40 +0300
            Re: LR(1) Parsing : Error Handling & Recovery Hans Aberg <haberg-news@telia.com> - 2014-07-20 01:38 +0200
              Re: LR(1) Parsing : Error Handling & Recovery Evangelos Drikos <drikosev@otenet.gr> - 2014-07-21 15:20 +0300
                Re: LR(1) Parsing : Error Handling & Recovery Hans Aberg <haberg-news@telia.com> - 2014-07-21 18:39 +0200
                Re: LR(1) Parsing : Error Handling & Recovery Evangelos Drikos <drikosev@otenet.gr> - 2014-08-26 13:44 +0300
                Re: LR(1) Parsing : Error Handling & Recovery Hans Aberg <haberg-news@telia.com> - 2014-08-29 11:13 +0200
                Re: split tokens; was LR(1) Parsing : Error Handling & Recovery Evangelos Drikos <drikosev@otenet.gr> - 2014-09-03 16:57 +0300
                Re: LR(1) Parsing : Error Handling & Recovery Hans Aberg <haberg-news@telia.com> - 2014-09-03 19:07 +0200
        Re: LR(1) Parsing : Error Handling & Recovery George Neuner <gneuner2@comcast.net> - 2014-07-20 01:19 -0400
          Re: LR(1) Parsing : Error Handling & Recovery wclodius@earthlink.net (William Clodius) - 2014-07-20 21:43 -0600
            Re: LR(1) Parsing : Error Handling & Recovery wclodius@earthlink.net (William Clodius) - 2014-07-21 21:44 -0600
          Re: LR(1) Parsing : Error Handling & Recovery Chris Dodd <cdodd@acm.org> - 2014-07-21 06:07 +0000
            Re: LR(1) Parsing : Error Handling & Recovery George Neuner <gneuner2@comcast.net> - 2014-07-25 21:58 -0400
              Re: LR(1) Parsing : Error Handling & Recovery Chris Dodd <cdodd@acm.org> - 2014-07-26 21:16 +0000
                Re: LR(1) Parsing : Error Handling & Recovery Hans-Peter Diettrich <DrDiettrich1@netscape.net> - 2014-07-28 14:43 +0200
                Re: LR(1) Parsing : Error Handling & Recovery Chris Dodd <cdodd@acm.org> - 2014-07-29 19:38 +0000
  Re: LR(1) Parsing : Error Handling & Recovery Eric <news@fx29.iad.highwinds-media.com> - 2014-07-16 16:40 -0400

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