Re: [Groff] X in \A'X' isn't ignored - bug report?

[Werner LEMBERG]

> Well exactly that was however the initial problem: while testing the
> manual of the MUA i maintain i got three occurrences of similar
> errors for \A'' on the result of a ".substring 0 1".

Ouch :-)  Not having an `interned' representation can be advantageous,
but here it's definitely a problem...

> Note how you cannot even say \A'\*[a]\*[b]', since the result seems
> to get expanded on the fly and breaks \A'' if that ends up as "\[".
> So this is anything but robust and as such defeats the sole purpose
> of \A''.

Yes, it can't handle backslashes because they are always handled
before the request sees them.  Note that you want expansion of \*[...]
and \n[...], but at the same time you want that a solitary `\['
doesn't cause an error.  How shall this work?

I can imagine to add another escape sequence (or request) that accepts
a string register as an argument, checking its contents.  Cf. the
`dei' request.


    Werner