[antlr-interest] Re: Antlr grammar to parse Java classfile?

[Ric Klaren]

Hi,

On Thu, Dec 06, 2001 at 07:02:10AM -0800, mzukowski at bco.com wrote:
> You are right, semantic predicates are ignored if you are guessing.  That's
> a gotcha that could be taken care of only by extending antlr or extremely
> ugly and unmaintainable syntactic predicates.
> 
> Hopefully for the java classfile format there should be no guessing...but
> this isn't a general solution to the "match n times" problem.

You might work around it with init actions (with devel versions and 2.7.2).
But it's ugly-ish. Init actions inside closures are now inside the loop
(before any lookahead tests etc.) it's even possible to break out of the
closure there (but this is not a documented feature, and I think it should
not be documented, better to implement it inside antlr)

Cheers,

Ric
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-----+++++*****************************************************+++++++++-------
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