Re: [aspell-devel] Loadable Filters and Context scipping

[Kevin Atkinson]

[CC aspell-devel, please do also]

On Wed, 18 Sep 2002, Christoph Hintermüller wrote:

> > 2) Allow setting of options for the loadable filters where the options are
> >    of the form "<filter>-<option".  This can be done in one of two ways.
> >
> >     1) Automatically allow all options of the form *-* to be set even if
> >        the option is not known.  When the option is retrieved,
> >        and after the filter module is loaded the config class will check
> >        if it is valid.
> >
> >     2) When an option <a>-<b> is set and is not known by the config
> >        class it should look for a special data with its name based
> >        on <a>.  If it can find one it should load the list and then
> >        check if the option is valid.  If it can't find one it will
> >        report that the key is not known.
> >
> >   #1 is the easiest but suboptimal because 1) the config class will have
> >   to accept any options with a dash in them and 2) if the value is invalid
> >   it will only be reported when the option is retrieved, not when the
> >   option is set.  
> >
> >   #2 would be the best but it would be more difficult to
> >   pull off.  Part of the problem is that when config sees an option of the
> >   form <a>-<b> it is diffacult for it to tell if it is corresponds to the
> >   option "<a>-<b>" or if it corresponds to option <b> for module <a>.

> 1) are there at all options of  "<a>-<b>"

Yes lots.  See common/config.cpp

> 2) do not allow names for filters which conflict with option name
>     <a> is either first part of option or filter name

By this do you mean if a filter is named foo than do not allow any options 
which start with "foo-" this way all options starting with "foo-" must 
belong to filter foo?  If so, this is already done.  But the problem is 
determining if option "barr-bla" is option "bla" for filter "barr" or 
option "barr-bla"?  What if the user meant "bar-bla" which is a valid
option?  The only way to know for shore is to see if filter "barr" exists 
and if so what options it has.

> 3) prefix filter options "f[ilter]-<a>-<b>"
> 4) introduce "--" as separator between aspell options and filter options
>     aspell -<ao> -<ao>-<bo> -- -<af> -<af>-<bf>
>     where "<ao>" and "<ao>-<bo>" are options for aspell
>     and all options following -- are passe to the option hanling of the    
>    loaded filters 
>    this would be "<af>" and "<af>-<bf>"

Off the two I like the idea of using "--" as a separator.  However that 
may cause compatibility problems with existing filters.

> 
> 2-3 would allow implicit filter loading
>      means if <a> could be uniquely associated with a known filter the filter
>      the filter could be loaded even if  the filter is not mentioned at all
>      (only bad if user mispelled aspell option)
> 
> 2-4 without implicit loading feature in 2-3 immediate error detection is 
>      possible as <a>-<b> neither would match any valid aspell option nor any
>      option for  filter <a> as the filter itselve is unknown 
>      after completing processing Configfile, Environment and Commandline

I think the option I like best is too use two dashes for filter options ie
"<filter name>--<filter option>"


--- 
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