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Re: GCC-3.2.2 bootstrap FAILURE: 1 reduce/reduce conflict in objc-parse.y
- From: Ziemowit Laski <zlaski at apple dot com>
- To: "Joseph S. Myers" <jsm28 at cam dot ac dot uk>
- Cc: Gabriel Dos_Reis <gdosreis at sophia dot inria dot fr>, gcc-bugs at gcc dot gnu dot org, gcc at gcc dot gnu dot org
- Date: Tue, 28 Jan 2003 15:30:39 -0800
- Subject: Re: GCC-3.2.2 bootstrap FAILURE: 1 reduce/reduce conflict in objc-parse.y
On Tuesday, Jan 28, 2003, at 15:08 US/Pacific, Joseph S. Myers wrote:
On Tue, 28 Jan 2003, Ziemowit Laski wrote:
A reduce/reduce conflict is certainly an annoyance, but it is not a
bug
-- bison has a deterministic, POSIX-annointed method for dealing with
it, which the grammar writer knows and expects.
It is, at very least, very bad grammar style, as discussed in the Bison
manual. The grammar should be changed (even though this may make it
more
complicated) to avoid the conflict.
Yes, but style is inherently aesthetic -- and hence subjective -- in
nature.
If you can find an equivalent grammar that is both intuitive to the
reader
and conflict-free, then by all means do so. But if your conflict-free
grammar
has more to do with Chomsky Normal Form than the language it describes,
then
I respectfully part company. :-) The grammar must, first and foremost,
be
readable and maintainable. Why else would one use a parser generator in
the first place?
--Zem
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Ziemowit Laski 1 Infinite Loop, MS 301-2K
Mac OS X Compiler Group Cupertino, CA USA 95014-2083
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