[antlr-interest] Debugger performance indicative of actual performance?

Jim Idle jimi at temporal-wave.com
Sat Feb 2 13:23:55 PST 2008


Extremely unlikely that the debug version is giving you any performance 
information. The biggest problem with that java stuff is that Java takes 
a hundred years to initialize, then the parser executes in 0.003 
seconds. You are probably seeing the startup time for the debugger and 
so on and not the actual parsing. 

Jim

> -----Original Message-----
> From: Mark Volkmann [mailto:r.mark.volkmann at gmail.com]
> Sent: Saturday, February 02, 2008 12:58 PM
> To: Steve Bennett
> Cc: antlr-interest
> Subject: Re: [antlr-interest] Debugger performance indicative of 
actual
> performance?
> 
> On Feb 2, 2008 3:27 AM, Steve Bennett <stevagewp at gmail.com> wrote:
> > Using the debugger to parse some typical input is taking what seems
> > like a very long time to me - 5-10 seconds for a 7kb file. How
> > indicative is this likely to be of the performance I'll get in a
> > production environment? How much can a grammar be tuned for
> > performance?
> >
> > I ask because 5-10 seconds could well be 2 or even 3 orders of
> > magnitude too slow...
> 
> I can't answer the question. However, I've never found it useful to
> process that much input in the debugger. Typically I'm using it to
> verify that my grammar is producing the AST that I want for certain
> kinds of input. The amount of input required to verify that for me is
> typically 10 lines or less. Looking through the AST for 7 KB of input
> seems overwhelming.
> 
> --
> R. Mark Volkmann
> Object Computing, Inc.




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