On Mon, Jun 08, 2015 at 02:49:44PM +0000, hru...@gmail.com wrote:

> Otto Moerbeek <o...@drijf.net> wrote:
> 
> > Tradiotionally, { } pattersn are not part of awk re's.
> >
> > Posix added them, but we do not include them afaik. Gnu awk only accepts
> > them if given an extra arg (--posix or --re-interval).
> >
> > I think this should be documented.
> 
> Although there is a clear theory about "regular expressions", I have the
> impression that there is no standard syntax. One needs to read again and
> again the documentation of programs that use them.
> 
> I am just missing a way to reference in a (f)lex action a previously
> matched subexpression (like with \m in a substitution with ed).
> 
> Why is this? Because lex is so old? And what does people do in these
> cases?
> 
> Rodrigo

Refering to subpatterns is not available in flex.  I suppose it is not
available since it would require a more complex re engine.
Interpretation of the lexical value should be "hand-crafted". 

        -Otto

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