Re: [groff] Spooky action at a distance in line adjustment...sometimes

[Ralph Corderoy]

Hi Branden,

> Can someone tells me why this happens?  And, more mysteriously, why it
> only _sometimes_ happens?

Two lines become three, disturbing parity.

> -       afmtodit [-ckmnsvx] [-a n] [-d desc_file] [-e enc_file]
> -                [-f internal_name] [-i n] [-o out_file] afm_file map_file 
> font
> +       afmtodit [-ckmnsx] [-a angle] [-d desc_file] [-e encoding_file]
> +                [-f internal_name] [-i n] [-o output_file] afm_file map_file
> +                font_name

The extra spaces are moved from the right end of the line to the left:

> -       The whitespace between a command-line option and its  argument  is  
> op‐
> +       afmtodit -v
> +
> +       The  whitespace  between  a command-line option and its argument is 
> op‐
>         tional.

This looks to me like nroff is alternating the added spaces between the
left and right ends of the line.  Kernighan and Plauger's excellent
_Software Tools_ does this with its simple roff IIRC, and says it's the
normal method to avoid `rivers' of space being perceived.
https://amzn.to/2MrnLO5

-- 
Cheers, Ralph.
https://plus.google.com/+RalphCorderoy