Re: Parse multiple versions of a document format?

[Hans Aberg]

On 8 Oct 2009, at 09:55, Rui Maciel wrote:

> I'm writing a parser for a document format which has a couple of  
> version out.
> The document format basically consists of a header field, where the  
> document
> format version is specified and whose format is the same across all  
> format
> versions, followed by multiple fields which differ between versions.
>
> Having that case in mind, what is the best strategy to write a bison  
> parser
> that is capable of parsing multiple versions of a document format?

It really depends how close the languages are. Think of a shell which  
handles different compilers for different languages. It would not be  
practical to build it together to one program. One the other hand,  
each compiler has set of option, which might compile a slightly  
different language. So it depends.

One possibility might be to let the header format select which  
compiler he rest should be sent to. If the languages then turn out to  
be close, they might be unified into one compiler with options; the  
header selects the options.

You might also try the Usenet newsgroup comp.compilers, giving more  
info about your format.

  Hans