bug#3312: 23.0.93; Use punctuation syntax for apostrophe in Info

> So this is a real problem for Info manuals.
> 
> > I don't know much about text-mode, but I wonder if even 
> > there it might make sense for ' to have syntax class
> > `punctuation' instead of `word'. Probably the answer is
> > "no", or that would already be the case. ;-)
> 
> AFAIK, the apostrophe has word syntax in text-mode to allow treating
> word contractions as one word (can't, it's, I'll).  I don't know
> whether this is grammatically correct or not

Yes, that is correct, and it is a good reason, as far as it goes.

The comment in the code is way off target, it seems.
What should be said there is what you said here: we treat apostrophe as
word-constituent because of its use in contractions.

Similarly, for possessive forms: the dog's bone.

But in both cases, contractions and possessives, it is a choice whether we want
to treat the apostrophe as word-constituent. The argument in favor is stronger
in the case of contractions - for the possessive "dog's" it is not clear that
you would want to include the "'s" when selecting a word.

> but at least the Unicode says that the category of the
> apostrophe is Punctuation, so perhaps we should
> change apostrophe syntax to punctuation in text-mode as well.

It _is_ punctuation, even in contractions such as "can't". The problem is that
it is punctuation _within a word_, so Emacs must choose whether it wants to
treat it as part of the word (for convenience) or strictly as punctuation.

I would probably vote for treating the syntax class in text mode as punctuation,
not word, but it would be good to hear other points of view.

I do feel that within Info mode it should be treated as punctuation. The use of
`...' forms in Info (even beyond Emacs doc) far outweighs the use of
contractions. In technical doc, we generally avoid using contractions anyway.