Re: tabs in `@example`

On Sat, Mar 14, 2026 at 06:02:16AM +0000, Werner LEMBERG wrote:
> 
> > At the start of a line, a tab character is treated the same as a
> > space character, i.e. it is ignored.
> 
> But a space character at the beginning of a line is not ignored in an
> `@example` environment!
> 
> Attached is a file that shows various combinations, together with an
> image of it.  For me it's strange that a leading tab gets ignored
> while a tab in any other situation is treated the same as a space (all
> within an `@example` environment).
> 
> 
>     Werner

Yes, I see that in an @example environment, the category code of space
is changed so that spaces are all printed, with no skipping spaces
at the beginning of a line or treating multiple spaces as a single space.
Nothing is done with tab characters, though - they are still treated
as spaces are treated by default.

I do not see a big problem here as the manual tells you not to use tab
characters anyway.

I have changed the text to the following:

  Do not use tabs in the lines of an example!  (Or anywhere else in
  Texinfo, except in verbatim environments.)  @TeX{} treats a tab as a
  single space character, so any text following a tab on a line will not
  be aligned as expected.

I feel it's better not to go into any more detail as it's possible that
there will be some even more obscure case where a tab character does not
behave exactly as described.