Hi Tadziu,
> Unfortunately, this also means inventing a new syntax. How should
> "\*", "\(", and "\[" be treated -- as groff escapes or as
> regular-expression magic?
Exactly. Taking an earlier suggestion for OR, it's valid now.
$ nroff | grep .
.if 'a'a'b'c'
b’c’
$
However, a new syntax is needed. I'd guess something at the start that
is currently invalid would indicate a whole new style of expression is
present, one with typical precedence, and more string matching
possibilities.
Cheers, Ralph.
