Re: Clean-up of forward-paragraph [Re: Beginingless paragraphs: second stab at a patch.]

[Richard M. Stallman]

    The current implementation doesn't test for paragraph-s\(tart\|eparate\)
    on the same line as the fill-prefix.  Should it?

I think it is important to see what past versions of Emacs did--for
instance, Emacs 19, before the support for a left margin was added.

If it was always done this way, then I think we should document it
clearly and not change it.  There are no users asking for changes in
this, and changing it would be risky.  However, if the past behavior
was confused or conflicting, we need to figure out which past behavior
to be compatible with.

Regarding your proposed definition of paragraphs, I am concerned about
possible incompatibilities.  In the "new" cases, those of
use-hard-newlines and nonempty left margin, we are not particularly
bound by compatibility.  However, in the other cases we are.

    (iv) A @dfn{divider (line)} is a line which is either a separator or has the
      fill-prefix (after any left margin) and is otherwise only whitespace.  
[This
      definition only applies when the fill-prefix is non-null.]

I think that together with (vii) are very hard to understand.

    (vi) When `use-hard-newlines' is non-nil, all paragraph boundaries are at 
hard
      BOLs.  A paragraph starts at a non-separator line, and ends at the next 
hard
      BOL.  Here, fill-prefix and paragraph-start are ignored.

Does this make some unstated assumption about how separator lines and
hard newlines relate to each other?  Perhaps it is just that the text
is confusing.

    (ix) If there happens to be a blank line before a paragraph start, this line
      is NOT regarded as being part of the paragraph.  [This is the problem 
which
      was at the heart of this thread.]

I am not quite sure what that means in concrete terms.  As I said
before, that blank line MUST be part of the following paragraph.
That is essential for compatibility.


I think that at present we should probably stick to fixing anything
which is most obviously a bug.  For instance, all paragraph beginnings
and ends should be at BOL; when it fails to do that, that is worth
fixing.  Bigger changes should wait for after the release.