Re: No documentation for filtering dictionary feature?

On Wed, 25 Aug 2010, Tom Lane wrote:

> Oleg Bartunov <oleg@sai.msu.su> writes:
>> On Tue, 24 Aug 2010, Tom Lane wrote:
>>> There's an entry in the 9.0 release notes saying that we've got
>>> filtering dictionaries now.  Cool, but I don't see any documentation
>>> of the feature in textsearch.sgml.  Shouldn't there be some?
>
>> Something like
>> http://developer.postgresql.org/pgdocs/postgres/unaccent.html ?
>
> No --- that's documentation for a specific contrib module, not
> documentation about the feature in general.  Currently the general
> description of dictionaries says that it's impossible for a dictionary
> to modify the input lexeme.  Clearly that needs some adjustment,
> but I'm not sure what, because the feature is not explained anywhere ;-)

Well, http://www.pgcon.org/2009/schedule/attachments/92_2009.pdf contains 
description of Dictionary API and new TSLexeme->flags: TSL_FILTER
If dictionary returns only one lexeme with TSL_FILTER flag, then that 
lexeme will be used as an input for the subsequent dictionaries in the chain.

I'm not sure, how to incorporate this into current documentation, since there
is no built-in filtering dictionary. Probably, it'd be nice to add filtering option
to simple dictionary to illustrate this feature.

Unfortunately, I'm busy-busy :(
    Regards,        Oleg
_____________________________________________________________
Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru),
Sternberg Astronomical Institute, Moscow University, Russia
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83