Re: unwanted space with `@url`

On Fri, Mar 13, 2026 at 09:33:14PM +0000, Gavin Smith wrote:
> On Fri, Mar 13, 2026 at 03:00:47PM +0100, Patrice Dumas wrote:
> > I am starting to wonder if it wouldn't be better to leave all the spaces
> > and comments as regular content in brace commands in the tree and let
> > the converter remove leading spaces and trailing spaces, by
> > calling a function that modifies the tree, by removing spaces after
> > conversion of each of the arguments, or by having a state where spaces
> > are ignored (which would not be really fit for removing trailing spaces,
> > actually).
> > 
> > Any idea on that subject?
> 
> The example you give, with @c comments inside a braced argument, would
> not work with texinfo.tex.

Actually, I know remember that we already discussed abount that, and, as
you explain the following cannot be correct in both Texinfo TeX and
texi2any:

@uref{ aaa @c comment } b
}
> I don't know the full implications of the change you suggest but if
> it complicates the program it doesn't seem justified, as @c shouldn't
> be used in such contexts anyway.

Even though the output is not well defined, and @c shouldn't be used in
such contexts, it is not document anywhere, and I think that we should
provide with sane output, in particular since in some situations the
texi2any and Texinfo TeX output will be similar.

What I will test, is to keep the spaces in the tree but mark them as a
special space to be ignored, and have functions to check if an argument
is empty.

> If it is a comment character, it is a different matter.  If "%" is
> replaced with character 0x7f (DEL) in the following, the input lines
> end up with trailing whitespace after the comments are removed.  The
> comment is removed at an early stage of processing and does not
> end up as part of the macro argument.

It is the same in texi2any, as DEL is put as a source mark early, as
soon as it is read, if I recall well.

-- 
Pat