Re: bison and/or antlr ?

On Sat, 07 Jul 2007 16:09:27 -0400, Chris F Clark
<cfc@shell01.TheWorld.com> wrote:


> ... The main place where LL parsing
> can fall down is in expressions. I find the rules that create
> precedence hierarchies to make parsing more complex and not
> simpler.


In fairness, I find crafting precedence hierarchies to be equally
complex in LR. In either case the resulting grammar always turns
uglier than I think it should ideally be.


Must be leftover S-expression envy.




> Predicated (and boolean) grammars are [after SLR or LALR
> parsing with precedence]. If you need this facility, one
> should carefully ask why and whether the resulting language
> is actually well-defined.


Just to be sure, you are referring to _semantic_ predicates? I have
never had a need for them that couldn't be served by parameterized
rules (which I consider a much cleaner solution). I do find
_syntactic_ predicates to be indispensable, however.




>Does that satisfy your curiosity?


In spades!
George

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