Re: [Groff] groff_char(7): Combination of characters vs. single unicode character

[Mike Bianchi]

On Tue, Dec 16, 2014 at 04:33:55AM +0100, Werner LEMBERG wrote:
> 
> > Do i understand correctly that the Info manual calls u2260 invalid
> > as a glyph name, but that, all the same, \[u2260] produces the
> > desired output?
> >     :
> 
> Similar to TeX, the distinction between characters, entities, and
> glyph names is unclear, unfortunately.
>       :
> So if you enter \[!=], groff converts `!=' to `u2260' (step 1), then
> to `u003D_0338' (step 2).
> 
> For the `utf8' output device, `u003D_0338' is found in
> `font/devutf8/R' (step a), returning character code U+2260 as the
> final output.
> 
> For the `ps' output device, `u003D_0338' is not found, thus it gets
> converted back to `!=' (step b), which is eventually found in file
> `font/devps/S', returning PostScript glyph name `notequal'.
> 
> 
> I hope this helps.  Patches to improve the docs are really welcome :-)

Also:
        Could a trace option be added so the path of \[u2260] interpretation
        could be seen?

        May a tool that shows the choices when there are "equivalent"
        interpretations?

-- 
 Mike Bianchi