Re: [Groff] List element spacing in MOM

[Peter Schaffter]

On Sat, Aug 01, 2009, Blake McBride wrote:
> I think space between list items should be controlled by .PARA_SPACE.  But
> rather than breaking everything out there, perhaps there should be a new
> macro called .LIST_SPACE that works like .PARA_SPACE but for lists.  Without
> this macro, a user is forced to create their own macro which encapsulates
> .ITEM in order to achieve this (likely common) effect.

.PARA_SPACE merely instructs mom to deposit a blank line (at the
current leading) between paragraphs.  The amount of space isn't
user-settable, so it would be a bad candidate for controlling space
between ITEMs, where a full linespace would introduce too much white
into a document element (the list) that needs to cohere.

.LIST_SPACE (with a user-settable value) isn't a good idea either,
since it has the potential to displace other document elements off
the baseline "grid" mom uses to prevent wandering bottom margins.
SHIM after QUIT_LISTS would correct this, but might result in
noticeably different amounts of whitespace after lists if there were
more than one (of differing lengths) on the same page.  Plus, the
space *before* lists would almost certainly differ from the space
after.

In other words, a certain amount of judgment is required if you want
to space ITEMs and prevent wandering bottom margins.  The mom
philosophy, inasmuch as there is one, is that if mom cannot reliably
make judgments in a consistent and typographically satisfactory
manner, then users are expected to make those judgments themselves
and implement them with the available tools.  In this case, it's
trivial to write a wrapper macro for ITEM.

-- 
Peter Schaffter