Re: Leaders

[Lennart Jablonka]

Quoth G. Branden Robinson:
> On second thought--in the form of empirical measurements rather than
> hand-waving conjecture--I think you've found a bug.

How so?

> Consider the following input, which I've degraded to an ASCII spelling
> of "chateau" to permit some comparative analysis (keep reading).
>
> $ cat long-leader.roff
> .ta \n(.lu
> .nf
>
> a
> air
> .fi
> The chateau into which my valet had ventured to make forcible
> entrance, rather than permit me, in my desparately wounded
> .sp
> entrance, rather than permit me, in my desparately wounded
>
> There are some hidden Control+A (leader) characters in the above.  Let's
> expose them.

No, there aren’t.   Your message does not contain the SOH bytes;  
you could as well put replacement “^A”s there.

> Now the output.
>
> $ nroff EXPERIMENTS/long-leader.roff | cat -s
> .................................................................
> a................................................................
> air..............................................................
> The chateau into which my valet had ventured to make forcible en‐
> trance, rather than permit me, in my desparately wounded......
>
> entrance, rather than permit me, in my desparately wounded.......
>
> This mostly looks great, except, uhh, the line after the hyphenated
> "entrance".  What gives?

You got what you asked for:  a field of periods with length such 
that the strings “entrance, rather […] wounded $periods” exactly 
fits from the start of the line to the tab stop.

If instead you do

        .ta \n(.lu
        .fi
        .nh
        The chateau into which my valet had ventured to make forcible
        entrance, rather than permit me, in my
        desparately wounded^A

(with C-a replaced by ^A (heh))

you get

        The  chateau  into  which  my valet had ventured to make forcible
        entrance,   rather   than   permit   me,   in   my    desparately
        wounded..............................................

without any hyphenation going on.   The point is that the width of 
the line of periods is determined by its position on the input 
line.   That is confusing, yet it also doesn’t usually matter:  
You seldom use tabs or leaders in filled text.