[antlr-interest] packrat vs. LL(*)

[Steven Obua]

>
> With a bit of up front effort it is usually much more time efficient
> (when using ANTLR) to write a good left factored grammar. Please
> remember this statement later when you are trying to track down where
> things are going wrong in your ambiguous grammar :-)
>

I agree that not using backtrack = true and doing left factoring  
results in faster and less resource intensive parsing.

Now, what you do is to equal ambiguous with bad. That's why I mention  
packrat. With it, you interpret your grammar in a different way (and I  
think in a very same way like when you set backtrack=true) which makes  
it non-ambiguous. The grammar is actually easier to understand now  
than it would be if you were "optimizing" it to suit a particular  
parsing technique.

Steven