Re: [Docutils-develop] Language support

[Guenter M. <mi...@us...>]

On 2010-09-24, David Goodger wrote:
> On Fri, Sep 24, 2010 at 19:16, Guenter Milde <mi...@us...> wrote:
>> currently, if a language is not supported by Docutils with a matching
>> module, conversion fails with ImportError.

>> I propose to change this to a warning, because in cases where no
>> auto-generated text is used the output would still be valid (with the
>> language tag given to the HTML output or used for hypenation etc. in
>> LaTeX)

> No objection.

> What would the default behavior be, if there is auto-generated text? English?

I think English is a reasonable default.

>> Also, I propose a :lang: role:

>> * in LaTeX and HTML it is possible to mark regions of the document as
>>  belonging to a different language.

>>  In HTML, this could be used to select a different font or a different
>>  voice in a screenreader.

>>  In LaTeX, the language setting also affects the hyphenation algorithm.

> Smells like a solution looking for a problem. If this is a real issue,
> please provide examples.

HTML has a "lang" attribute

  Language information specified via the lang attribute may be used by a
  user agent to control rendering in a variety of ways. Some situations
  where author-supplied language information may be helpful include:

    * Assisting search engines
    * Assisting speech synthesizers
    * Helping a user agent select glyph variants for high quality typography
    * Helping a user agent choose a set of quotation marks
    * Helping a user agent make decisions about hyphenation, ligatures,
      and spacing
    * Assisting spell checkers and grammar checkers

  -- http://www.w3.org/TR/html401/struct/dirlang.html

Practical examples:

Ensure that the German name is hyphenated according to German grammar
rules (if word-wrap is active) and pronounced correctly by a
screen-reader:

  To go to the main station you need to change tram at 
  <span lang='de'>Hohenzollernplatz</span>.


Ensure that LaTeX uses the right font encoding:

  We wanted to go to the {\selectlanguage{russian} красная плошадь}.


Both should be possible without ressorting to 'raw'.

> Alan's multiple-language concern is also valid.

If I understand it right, it's one of the reasons for my proposal: I
want to be able to mark a word, a quote or a section as beeing in a
different language than the rest of the document.


I agree that a role might not be the best/only approach to this problem.

a) roles do not have arguments
b) it would not solve marking e.g. a quote.


Alternatives:

a) class arguments (lang-<language tag>)

   e.g.: ``.. class:: lang-de`` would set lang="de" for the following object.
   
b) lang directive   

   e.g.: ``.. lang:: de`` would set lang="de" for the following object.

c) :lang: attributes to all relevant rst objects

   .. line-block::
      :lang: de

      ein deutsches Gedicht
      
      
> How would your proposal be different/better than declaring roles in
> the document? E.g.

> .. role:: spanish

> or

> .. role:: lang-spanish

> or

> .. role:: lang-es

This would set a class attribute on a span that still requires a style
setting to be understood by the user agent.

How about a base-role "lang" that can be used to create custom language
setting roles::

 .. role:: es(lang)
 
 
Günter