Re: End-of-sentence spacing

[Dave Kemper]

On 12/20/20, Peter Schaffter <peter@schaffter.ca> wrote:
> Perhaps I should have been more verbose and written: According
> to the info(1) manual, initially both the WORD_SPACE_SIZE and
> SENTENCE_SPACE_SIZE are 12; since this prevents SS from being larger
> than WS, it effectively disables sentence spacing.

Unfortunately, the info manual uses the term "sentence space" not in
its conventional meaning of "the amount of space between sentences"
but as "the amount of space to *add* to the word space between
sentences."  The info manual does spell out this meaning, so there's
technically no ambiguity, but "sentence space" having a different
meaning from normal typographic usage seems needlessly confusing.
(I'm not sure where this unconventional usage originates; probably not
as far back as CSTR #54, since in those days .ss didn't have a second
parameter.  It might be a groff-ism, thus something we could fix
without breaking semantic compatibility.)

Thus the way to make sentence spaces the same size as word spaces is
".ss 12 0".  Groff's default of ".ss 12 12" separates sentences by
twice as much space as words (or, in fill mode, by *at most* twice as
much space, since word spaces are stretchable but sentence spaces are
not, a(n undocumented) situation http://savannah.gnu.org/bugs/?58450
seeks to remedy).