Re: [Groff] Creating a table macro

[Ted Harding]

On 18-May-11 01:59:23, Automation Department wrote:
> Would like to create a very simple table macro.
> eg.,
> 
> .de TABLE
> .TS
> box expand;
> l s
> l l.
> \fI\\$1\fP
> 
> ..
> 
> This does not work though other similarly crafted macros do.
> It 'starts' the macro at the macro definition. Do I need to
> escape it?
> 
> Also, if I just do:
> 
> .de TABLE
> box expand;
> l s
> l l.
> \fI\\$1\fP
> 
> ..
> 
> Then call with
> 
> .TS
> .TABLE "Macro Junk"
> column1       column2
> .TE
> 
> I get:
> tbl:final_rpt.roff:369: `.' not last character on line
> tbl:final_rpt.roff:369: giving up on this table
> 
> Just hoping to save some typing.
> 
> Thanks!
> - -- 
> Chad Roseburg

To deal first with your second example:

The problem here is that the "." at the beginning of the
second line will be interpreted as the "." that normally
occurs at the end of the formatting lines. Note that this
is different from the interpretation of "." when it occurs
in a numerical context, such as when you are defining a
minimum column width -- e.g.

  .TS
  box
  lw(1.5i) l.

since that occurs inside "w()" where tbl is expecting
to find a numerical expression. When the "." occurs at
"top level" as in your ".TABLE ..." it will be taken at
"face value", i.e. as the terminator for the formatting.

Now for your first example. The problem here is that
your macro ".TABLE" will be interpreted by troff, not
by the preprocessor tbl. Note *pre*processor -- tbl
does its work before troff sees the results. If troff
expands a macro (such as your .TABLE) then it is too
late -- the processing has moved on past tbl.

Incidentally, you will get no result at all unless you
include the ".TE" at the end of the macro definition,
as in

.de TABLE
.TS
box expand;
l s 
l l.
\fI\\$1\fP
.TE
..
.TABLE "Macro Junk"

but even then it will not be the result you want. This
is because tbl has already done its work, as explained
above, as you can verify by deleting the line
.TABLE "Macro Junk"
(thus not calling the macro at all) -- tbl sees the .TS
and .TE, ignores the fact that they are inside a macro
definition (tbl does not recognise macros), and simply
creates troff code for what it finds between them.

Probably the simplest way to "save some typing" is to
use the copy-&-paste functionality of your editor to
copy down an existing instance of the table setup lines.
Some editors will alow you to define a block of text
and give it a name, so that when you invoke the name
it will automatically insert the whole block.

Hoping this helps,
Ted.

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E-Mail: (Ted Harding) <address@hidden>
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Date: 18-May-11                                       Time: 20:00:01
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