Re: [Groff] tbl and inter-column spacing

[Joerg van den Hoff]

On Wed, Jul 16, 2008 at 06:34:48AM +0200, Werner LEMBERG wrote:
> > I have not used `tbl' for some time and now see the following
> > behaviour, which was not present before, I'm quite sure: [...]
> 
> Source code, please.
> 
> > and it's still funny: the table is rendered completely (but
> > extending into the right margin), only the inter-column space is
> > squeezed to zero, it seems. now: is _this_ intended behaviour?

attached  is  an example (using `ms' macros). although there
is nothing specific to it and I  think  in  the  meantime  I
found  out  what's  going on: the squeezing is caused by the
`expand;' directive when the table gets wider  as  the  line
length,  it  seems:  if  you  remove  the `expand'   without
altering the point size the table simply does no longer  fit
on the page and is clipped.

wheras,  empirically,  it  seems  that the `expand' works in
such a way that it actually shrinks the table if it was  too
wide  in  the  first  place.  which  sure is a feature in my
view... but apparently  it  shrinks  the  table  as  far  as
possible  without  causing  overlap  of columns and that was
what I've seen causing the seamless merging of some  entries
within the same row. question: would it not be nicer to stop
the shrinking when the inter-column spacing has dropped  to,
say, one "m" space or something like that?

another remark: the `tbl' manpage states

expand -- Makes the table as wide as the current line length.

which is not quite right regarding what's happening for wide
tables as in my example: actually the table is  squeezed  if
it  is  too  wide  in the first place, but final table width
gets larger than the line length if inter-column spacing has
reached a zero value. Maybe one should add a corresponding
remark to the manpage, e.g.

expand -- Makes the table as wide as the current line length
          if possble. For wide tables the effect might actually
          be a squeezing of the inter-column spacing in the table
          in an attempt to keep it completely on the page. The
          table might extend into the right margin in this case.



> > should one not get some kind of warning ("table to wide" or
> > something like that)?
> 
> I'm not sure that groff has such warnings built in.

nor am I :-). question is, would it be possible for `tbl' to
do a final check of table width vs. line  length/page  size?
and would it be difficult to implement this check/warning?

joerg

> 
> 
>     Werner

tt.trf
Description: Text document