Some comments on the documentation (here: groff manual)

[Oliver Corff]

Dear All,

as I am trying to learn more of the groff language, not so much for
modifying existing layouts or creating layout macros, but rather for the
purpose of computing contents like character tables etc., I came across
two issues in the groff manual (at least in the version which is
currently available as:
https://www.gnu.org/software/groff/manual/groff.html)

1) 5.20 Conditions and loops, 5.20.2 if-else

The two escapes \{ and \} are introduced, but the example below
immediately uses \{\ (note the additional backslash). Is it possible to
add a short phrase to the effect if and why the line-continuation
character \  is necessary here?

2) 5.3 Expressions

   gtroff has most arithmetic operators common to other languages:
   - Arithmetic: ‘+’ (addition), ‘-’ (subtraction), ‘/’ (division), ‘*’
   (multiplication), ‘%’ (modulo).

While a glance at examples of code snippets clearly indicates that
gtroff grammar is based on infix notation, I'd appreciate, for clarity,
that this be stated here.

And, I dearly miss an example of how to compute an arithmetic operation:
what is the correct grammar, and how is the result of the computation
assigned to a register? Is it "\n[z]=\n[x]+\n[y]" ? (hint: it doesn't
work that way).

My workaround these issues, besides trial and error, was to inspect the
macro files (ms, mom etc.) for use cases, but it would be nice it this
information were found in the manual.

Thanks a lot, and best regards!

Oliver.


--

Dr. Oliver Corff
Mail: oliver.corff@email.de