@uref suggestions, comments welcome

[Marc Herbert]

Following the recent discussion on this list about @uref, here is some
summary of the ideas, and a detailed enhancement suggestion.



The issue is here : some people don't like to print URLs inline on
paper, especially when they are long (whereas these long and
direct-access URLs are without doubt very useful when hidden in an
anchor in the HTML output). They prefer to have URLs only in
footnotes, or have only shorter ones printed, or even no URL at all. 
Why ? 

 - they find them typographically ugly
 - they cause hyphenation problems
 - they take time to type on keyboard. A shorter typing session
followed by a few clicks is more ergonomic (this is naturally possible
only with well designed web sites) 
 - sometimes people read paper without internet access at hand
 - paper documents have a longer lifetime than HTML ones. It can be
better to use on paper alternative, more general URLs than in HTML,
because more general URLs also have a longer lifetime than more
specific, direct-acces ones.

The only alternative *today* for this problem is to completely avoid
URLs on paper, thanks to the "third argument trick" (see recent @uref
documentation), or by defining hand-made macros. Thanks to this third
argument trick, it is possible to define easily backward compatible
enhancements to @uref, since when used, the second argument is yet
ignored. 

 - concerning HTML output : nothing changes in this proposal

 - concerning dvi and info output :

    if the second argument is...

        * ... empty, then the URL is lost. Same as before. 
Compatibility is maintained.

        * ... a shorter URL, then this URL is used on paper instead of
the first big URL

        * ... the keyword "footnote", then the complete URL given as
the first argument is printed, but only as a footnote. 


Without even having read texinfo source codes, I dare to affirm these
enhancements can be not so difficult to implement (?)  But I don't
think this behaviour can be achieved by only using macros, because of
the test that has to be done on the keyword "footnote" (please correct
me)

Comments (public, private) welcome.