[antlr-interest] Rewrite rule question

Jamie Penney jpen054 at ec.auckland.ac.nz
Mon Feb 18 14:07:17 PST 2008


Jim Idle wrote:
>> -----Original Message-----
>> From: Jamie Penney [mailto:jpen054 at ec.auckland.ac.nz]
>> Sent: Monday, February 18, 2008 1:32 PM
>> I have a set of rewrite rules like so:
>> primary_expression :
>>         (literal | simple_name | ... )
>>         (DOT IDENTIFIER some_rule -> ^(PRIMARY_EXPRESSION 
>>     
> $primary_expression DOT IDENTIFIER type_argument_list_handler)
>   
>>             |    ... )*
>>
>> If there are none of the last group, then no rewrite rule is 
>>     
> triggered.
>   
>> If I specify a rewrite rule on the first group, will the rewrite rules
>> in the second group overwrite the ones from the first if they are
>> triggered (this is the behaviour I want)? 
>>     
>
> Yes. But you may find that you have to supply rewrites for the other 
> alts when you supply a rewrite for one of them. You could place that in 
> a subrule if you want to avoid having to do that.
>
> Jim
That should be fine. I am trying to preserve the existing rewrite rules 
if I can.

Thanks,
Jamie Penney


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