Re: branch-1_4 off-by-one in line reporting

[Gary V. Vaughan]

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Hi Eric,

On 17 Oct 2006, at 17:47, Eric Blake wrote:
> Gary V. Vaughan <gary <at> gnu.org> writes:
> > On 12 Oct 2006, at 16:13, Eric Blake wrote:
> > > I still want CVS head to follow Solaris' parsing precedence
> > > rules (macros, then quotes, then comments), rather than the current
> > > behavior (comments, macros, quotes).
> >
> > Can you remind me why that is?
>
> Hmm, in Solaris, when the prefix was ambiguous between quote and  
> comment, it
> always chose quote when given a chance, even when quote was the  
> shorter
> prefix.  In GNU, on the other hand, the comment was always  
> recognized first.
> If either implementation were a strictly greedy parser, then you  
> would expect
> the longer start token to be recognized in preference to the  
> shorter one.

Although it makes perfect sense the way it is (on Solaris) considering
that POSIX documents that a matched quote token should be taken in
preference to a not yet matched comment token.

> If anything, the reason I am proposing delaying
> the recognition of comments until after macro names and quote  
> starts have been
> recognized is to match historical behavior, and so that GNU M4  
> parsing at least
> follows the order that the three token types are mentioned in POSIX.

Thanks for the nice explanation.  Yes, I definitely agree with
you now; can you add it to the TODO list, please?

Cheers,
        Gary
- --
Gary V. Vaughan      ())_.  address@hidden
Research Scientist   ( '/   http://blog.azazil.net
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