bug#70832: 30.0.50; repunctuate-sentences should respect sentence-end-double-space

[Juri Linkov]

>> >> In paragraphs.el there is a variable  'sentence-end-doulbe-space` that 
>> >> indicates where we should expect
>> >> sentences to end with one or two spaces after a period. In the same file 
>> >> a command is provided called
>> >> "repunctuate-sentences", which steadfastly ignores the value of this 
>> >> variable and expands all single-space
>> >> endings to two-space endings.
>> >>
>> >> It strikes me that the naming of this command does not imply that it will 
>> >> insist on two-spaces (even if the docs
>> >> say so), and it would be more sensible and offer more utility for it to 
>> >> respect the users wishes.  As the variable
>> >> default to `t, changing this function would have zero impact on the 
>> >> default behaviour.
>> >
>> > Patches to allow repunctuate-sentences heed the value of
>> > sentence-end-double-space are welcome.
>> 
>> The purpose of repunctuate-sentences is
>> to put two spaces at the end of sentences.
>> What should it do when sentence-end-double-space is nil?
>
> Leave just one space between sentences, I think.

A special command 'repunctuate-sentences' that uses 'query-replace'
is required for the value 'sentence-end-double-space' because
replacements from 1 space to 2 spaces are ambiguous (e.g.
such text as "e.g." still require 1 space after the period),
therefore the command should query every replacement.
OTOH, the reverse replacement from 2 to 1 space is quite
straightforward.