Martijn van Oosterhout wrote:
On Sun, Jan 22, 2006 at 09:04:14AM -0500, Andrew Dunstan wrote:
If you don't like relying on file order to resolve this, appropriate
use of %prec would have the same effect (just like for operator
precedence). The output file tell you which way bison went.
If we allow shift/reduce or reduce/reduce conflicts, debugging future
development becomes more difficult. Right now we have the nice property
that if you see one of those you know you've done something wrong (and
using the expect directive isn't really a good answer, and only applies
to shift/reduce conflicts anyway).
But that's the point of the %prec directive. To force bison to choose
one or the other, thus removing the warning... For an ambiguity that
only appears in one statement, it seems a better solution than upgrade
SET to a new class of identifier.
Quite so. We already use %prec extensively. All I was pointing out was
that using file order isn't an acceptable option.
Presumably the effect in this case would be to prevent anyone from using
SET as an alias unless there was a preceding AS.
cheers
andrew
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