Re: parsing theory dubts (Hans Aberg)
30 Mar 2003 21:19:22 -0500

          From comp.compilers

Related articles
parsing theory dubts (Davide Rizzo) (2003-03-30)
Re: parsing theory dubts (2003-03-30)
| List of all articles for this month |

From: (Hans Aberg)
Newsgroups: comp.compilers
Date: 30 Mar 2003 21:19:22 -0500
Organization: Mathematics
References: 03-03-177
Keywords: parse, comment
Posted-Date: 30 Mar 2003 21:19:22 EST

"Davide Rizzo" <> wrote:

>[... LALR is a superset of LL. ... -John]

Thise is not entirely true. Here is a quote from Akim Demaille in the Help
Bison list 2002/01/17:

This is not absolutely true, although it is in practice. IIRC the
result holds when there are no empty rules. See for instance


or the errata of Andrew Appel about this book on compiler


                Page 64. Figure 3.26 incorrectly shows LL(1) as a subset of
                SLR. In fact, LL(1) is not even a subset of LALR(1): there is
                an LL(1) grammar that is not LALR(1).

    Hans Aberg * Anti-spam: remove "remove." from email address.
                                    * Email: Hans Aberg <>
                                    * Home Page: <>
                                    * AMS member listing: <>
[Oh, right. Oops. -John]

Post a followup to this message

Return to the comp.compilers page.
Search the comp.compilers archives again.