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Re: Rvalue given() blocks

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Rafael Garcia-Suarez
July 20, 2009 08:22
Re: Rvalue given() blocks
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2009/7/20 Vincent Pit <>:
>> This is extremely neat.
>> However by looking at the perly.y part of the patch (I haven't looked
>> at the other ones yet) I see that you add switch as a derivation for
>> the term rule, but switch can begin with a label. And terms don't.
>> I'd rather have a new rule
>> switch : label given;
>> and add given to term.
> The problem in this approach is that it makes bison complain about some
> reduce/reduce conflicts. I'm unsure if those are genuine or not.

I think they are.
Without looking at the code: I think bison doesn't know whether he
should reduce as a given-expression, or as a given-statement. And
without infinite lookahead that's not going to work.
If we remove given-statement, that will mandate a semicolon at the end
of a given block, as for any expression. That's not nice either.
Basically that construct is too ambiguous now...

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