Joel,
One possible solution would be to allow the grammar writer to
specify weights for a particular reduction. When a conflict
occurred the one with the greatest weight would be chosen.
A conflict action (which we proposed earlier) could be encoded with these
weights so it could choose a reduction before a split could occur.
This weights idea is very grand and it sounds like a huge amount of
work. I'm not sure the effort is worth it (to implement it and
then to use it).
I have no problem with splits (apart from the performance penalty
they cause). They are a natural occurrence in a glr grammar.
The whole point is that there is insufficient information at
the split point to make a decision. Once more tokens have been
parsed, then we have a better idea what needs to be done.
Bison needs to make life easy for people to make decisions when
an ambiguity cannot be resolved.
On the subject of new features. I have just been bitten (again)
by not being able to execute any actions in when multiple parse
stacks are in existence. Having a way of specifying a non-deferred
action would solve a recurring problem of mine.
--
Derek M. Jones tel: +44 (0) 1252 520 667
Knowledge Software Ltd mailto:[EMAIL PROTECTED]
Applications Standards Conformance Testing http://www.knosof.co.uk
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