[Nepomuk] Building and using recursive Baloo queries

[Vishesh Handa]

On Tuesday, February 18, 2014 10:40:13 AM Denis Steckelmacher wrote:
> Hi,

Hey Denis

> 
> I'm reading the source code of Baloo to see if porting the Nepomuk
> user-query parser that I developed during the summer would be an easy
> task. Everything feels clean and well-thought, so congratulations to
> everyone involved!
> 
> In Nepomuk, queries were built using a tree of Nepomuk2::Term objects. I
> discovered that Baloo still has a Term class (in src/core), that allows
> operations and subterms, and that a Baloo query can use such terms. But
> what does it do with this term? Baloo queries also seem to be described
> using a search string, types and filters, so how the term and the
> filters are related?
> 

All of these queries are sent to the "Search Stores", these search stores have 
to parse the queries and return some values.

All search stores currently use Xapian as the query backend. So the 
Baloo::Query will get translated into a Xapian::Query object. Checked out the 
implementation of one of the search stores, it'll make things easier to 
understand.

-- 
Vishesh Handa