Paragraphs (and sentences) in Emacs cannot span pages.

Paragraphs (and sentences) in Emacs cannot span pages.

[Alan Mackenzie]

Hi, Emacs!

In printed material, sentences and paragraphs can (and frequently do)
start on one page and finish on the next.

In Emacs, in Fundamental mode and even in Text mode, the default values of
paragraph-s\(tart\|eparate\) include a ^L, thus chopping paragraphs (and,
indirectly, sentences) into two at page boundaries.  So, for example, in
the following:

   This sentence goes over from one page
   ^L
   to the next.

, M-a, M-e don't do what somebody used to reading dead trees might expect.
Neither do M-{ and M-}.

Is this really the Right Thing?

-- 
Alan Mackenzie (Munich, Germany)

Re: Paragraphs (and sentences) in Emacs cannot span pages.

[Stefan Monnier]

>    This sentence goes over from one page
>    ^L
>    to the next.

In my experience, ^L is generally used in Emacs for logical pages, not for
physical pages, so a ^L in the middle of a paragraph doesn't make
much sense.

I guess if you see such a ^L it's inside something like an RFC, where the
two pages are separated not just by ^L but also by footer&header so it'd be
hard for Emacs to figure out what's a paragraph.

Could you give more info about the precise case(s) where you bumped into ^L
in the middle of paragraphs?


        Stefan

Re: Paragraphs (and sentences) in Emacs cannot span pages.

[Alan Mackenzie]

Hi, Stefan.

On Tue, 6 Sep 2005, Stefan Monnier wrote:

>>    This sentence goes over from one page
>>    ^L
>>    to the next.

>In my experience, ^L is generally used in Emacs for logical pages, not
>for physical pages, so a ^L in the middle of a paragraph doesn't make
>much sense.

In this case, having the ^L in the paragraph-s... variables doesn't add
anything.

>I guess if you see such a ^L it's inside something like an RFC, where the
>two pages are separated not just by ^L but also by footer&header so it'd be
>hard for Emacs to figure out what's a paragraph.

I suppose one would want an RFC mode there, where page-delimiter is set
up to match the footer+header.

>Could you give more info about the precise case(s) where you bumped into ^L
>in the middle of paragraphs?

I'm documenting what pages, paragraphs and sentences are, in the elisp
file searching.texi (page "Standard Regexps").

I haven't actually come across any difficulty that this paragraph break
at ^L causes, yet at the same time, don't really see what its purpose is.

I'm thinking about what I should say about this in searching.texi.

>        Stefan

-- 
Alan.

Re: Paragraphs (and sentences) in Emacs cannot span pages.

[Richard M. Stallman]

    In printed material, sentences and paragraphs can (and frequently do)
    start on one page and finish on the next.

That's because the pages are broken automatically.
That's not how people normally use ^L in files they edit.

Could you tell me more about the files you are editing
and why they have ^L in the middle of paragraphs?

Re: Paragraphs (and sentences) in Emacs cannot span pages.

[Alan Mackenzie]

Hi, Richard!

On Wed, 7 Sep 2005, Richard M. Stallman wrote:

>    In printed material, sentences and paragraphs can (and frequently
>    do) start on one page and finish on the next.

>That's because the pages are broken automatically.
>That's not how people normally use ^L in files they edit.

>Could you tell me more about the files you are editing
>and why they have ^L in the middle of paragraphs?

I haven't had any trouble with any actual file.

It was more a philosophical thing that occurred to me whilst documenting
pages, paragraphs and sentences in @node Standard Regexps in
searching.texi.  I was wondering about the motivation for having
paragraphs and sentences constrained to be within single pages.

This is surely something which _can't_ be changed now.  If the defaults
of paragraph-s\(tart\|eparate\) were changed to allow paragraphs to span
pages, then lots of little things would stop working.

But this is one way in which Emacs's pages/paragraphs/sentences don't
correspond with what people might expect, and I think I should write a
bit about it into the documentation, also telling hackers how to set
things up to have paragraphs spanning page breaks.

-- 
Alan Mackenzie (Munich, Germany)

Re: Paragraphs (and sentences) in Emacs cannot span pages.

[Richard M. Stallman]

    >In my experience, ^L is generally used in Emacs for logical pages, not
    >for physical pages, so a ^L in the middle of a paragraph doesn't make
    >much sense.

    In this case, having the ^L in the paragraph-s... variables doesn't add
    anything.

It handles the case where paragraphs are separated by a line containing
only ^L.

Re: Paragraphs (and sentences) in Emacs cannot span pages.

[Richard M. Stallman]

    But this is one way in which Emacs's pages/paragraphs/sentences don't
    correspond with what people might expect,

On the contrary, it is exactly what people expect--for hand-edited
files.