[antlr-interest] Problems with AST parsers in Antlrworks 1.0.1

Jean Bovet antlr-list at arizona-software.ch
Sun Jun 3 11:06:35 PDT 2007


Yes, it is fixed in 1.0.2.

Regards,

Jean

On Jun 3, 2007, at 5:45 AM, Johannes Luber wrote:

> Robin Davies wrote:
>> Probably a very beginner antlr question, but maybe not.
>>
>> I'm trying to debug the CMinus.g AST parser sample >from the manual:
>>
>> http://media.pragprog.com/titles/tpantlr/code/trees/CMinus/CMinus.g
>>
>> When I start the AnltrWorks debugger, and step through a couple of
>> steps, in AntlrWorks 1.01, I get the following exception:
>>
>> Exception in thread "main" java.lang.NullPointerException
>>  at org.antlr.runtime.debug.DebugTreeAdaptor.nil 
>> (DebugTreeAdaptor.java:45)
>>  at CMinusParser.aexpr(CMinusParser.java:1731)
>>  at __Test__.main(__Test__.java:22)
>> (And the same with pretty much anything that has options  
>> {output=AST;}
>> // build trees, I think.
>>
>> I'm coming to this with a C# background and not a whole lot of Java
>> experience. There's a very real risk that I have my classpath set up
>> properly. I have a classpath to the source distribution, but no
>> classpath to the Antlworks jar. Is that wrong?
>>
>> My classpath:
>>
>> .;C:\Program
>> Files\Java\jre1.5.0_10\lib\ext\QTJava.zip;C:\usr\src\antlr-3.0\lib\
>> antlr-2.7.7.jar;C:\usr\src\antlr-3.0\lib\antlr-2.7.7.jar;C:\usr\src 
>> \antlr-3.0\li
>> b\antlr-3.0.jar;C:\usr\src\antlr-3.0\lib\antlr-runtime-3.0.jar;C: 
>> \usr\src\antlr-
>> 3.0\lib\stringtemplate-3.0.jar
>>
>> Environment: Vista, JRE 1.5.
>
> I believe this is a bug in ANTLRworks. Maybe it is already fixed in
> 1.0.2. The workaround is to call the ANTLR on the command line.
>
> Best regards,
> Johannes Luber



More information about the antlr-interest mailing list