Re: How to solve this kind of ambiguities?

[Hans Aberg]

Your question is rather out of context, so it is hard to give an answer.

There is a Yacc-like grammar for C++, you might look at that one:
  http://www.parashift.com/c++-faq-lite/compiler- 
dependencies.html#faq-38.11

Otherwise, you might check out the Usenet newsgroup comp.compilers,  
and its FAQ, published there monthly.

  Hans Aberg


On 3 Aug 2006, at 09:36, Dong Tiger wrote:

> Look at the following expression( c-like syntax):
>
>       1 - 2 * (TYPE_OR_VAR) - 1
>
> The real token type of TYPE_OR_VAR is unknown. The expression could be
> parsed as the following two options:
>
> 1. TYPE_OR_VAR is a typename. Then "(TYPE_OR_VAR)-1" is a cast  
> expression.
> And the expression equals to:
>      1 - ( 2 * ( (TYPE_OR_VAR)-1))
>
> 2. TYPE_OR_VAR is a variable. Then the expression equals to:
>      1 - 2 * TYPE_OR_VAR - 1
>
> I would like to choose the second option but I can't do it with "% 
> dprec". As
> when the ambiguity happens, the two options
> are shifted by the same rule.
>
> What can I do to get around this problem?
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