[antlr-interest] C++ is slower than Java?
Trey Spiva
Trey.Spiva at embarcadero.com
Mon Feb 25 06:37:07 PST 2002
Did you use one of the java Buffered input classes. Because as far as I can
tell the C++ streams
class are not buffered. Therefore, every time the C++ antlr runtime reads a
character it is
going to the disk to retrieve the character. I drastically increased the
speed of the parser by
implementing my own buffer.
> -----Original Message-----
> From: keren_jefet [mailto:keren_jefet at yahoo.com]
> Sent: Sunday, February 24, 2002 6:24 AM
> To: antlr-interest at yahoogroups.com
> Subject: [antlr-interest] C++ is slower than Java?
>
>
> Hi,
>
> I have tested the java.g example both on Java-generated parser, and
> on Cpp-generated parser (antlr-2.7.1, buildAST=true).
> Surprisingly, I found out that the Java parser, was significantly
> faster than the Cpp one, especially when handling long java source
> files. (sometimes even 600% faster...)
>
> How can that be?
> Is this related to the specific java.g grammar definitions, or maybe
> it is true for all parsers, no matter of the grammar complexity?
>
> Thanks,
> keren.
>
>
>
>
>
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