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Re: %union foo bar baz and others { ... }

From: Paul Eggert
Subject: Re: %union foo bar baz and others { ... }
Date: 14 May 2003 13:11:54 -0700
User-agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3

On 28 Mar 2003 Akim Demaille <address@hidden> writes:

> I don't think that this backward compatibility is really an issue.
> One hardly finds grammars without semicolons,

Perhaps not in the community closely related to Bison, since Bison
1.50 and 1.75 required them.  However, 1.50 and 1.75 by no means took
over the world.  Every other Yacc implementation allows rules without
trailing ";" so I would not be at all surprised that the problem will
come up in the future when people move grammars to Bison.  I'd rather
encourage these people to migrate, rather than hassle them with minor
issues like trailing semicolons.

I just checked, and Debian ships only Bison 1.35 (in stable) and
1.875a (in testing and unstable), so current Debian users are like
Yacc users in this respect.  (Those version numbers are yet another
indication that we need to generate a stable version of the post-1.35
Bison soon.)

> - remove the 'id:' stuff from the scanner per se, but...
> - introduce a buffering between the scanner and the parser that
>   groups an 'id' followed by a ':'.

I could go along with that, but I'd like to see the change first.
I'm not yet convinced that it will simplify the code much.

> - get ready to cease the parsing of the actions in the grammar
>   scanner.

Similarly, I could go along with this.  But I don't want to scan the
actions twice.

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