Re: Differences in `ne` and `bp` line-breaking behavior

[Steve Izma]

On Wed, Dec 04, 2024 at 12:00:52PM -0500, Douglas McIlroy wrote:
> Subject: Re: Differences in `ne` and `bp` line-breaking behavior
> 
> I don't see this wording as an improvement:
> 
> >   .ne d    Advance drawing position to the next vertical
> >            position trap and spring the trap, if it is
> >            nearer than distance d (default scaling unit v).
> 
> The proposal uses nonstandard terminology ("drawing position"),
> and is ambiguously worded. It is easy to misread "if" as applying
> only to the "spring" clause rather than to the compound of
> "advance" and "spring".

I'm not sure about "drawing position", but simply recasting the
sentence clarifies or corrects the logic, e.g.:

.ne d   If the next vertical position trap is nearer than
        distance d (default scaling unit v), advance drawing
        position to it and spring the trap.
        
Maybe "advance the current vertical position to it", since I
believe that \n[.d] becomes equal to the trap position once it's
sprung.

> Also .ne is effective in the absence of traps, a fact that groff(7)
> misses, too.

This is news to me. Does it mean that the default page length
automatically creates a trap? Or does .ne have a side effect?

        -- Steve

-- 
Steve Izma
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