[Xapian-devel] Composition of NEAR and OR

[Jean-Francois Dockes]

The following piece of code triggers an 'unimplemented' exception with the
message:
 "Can't use NEAR/PHRASE with a subexpression containing NEAR or PHRASE"

      Xapian::Query or1(Xapian::Query::OP_OR, 
		    Xapian::Query("one"), 
		    Xapian::Query("two"));
      Xapian::Query or2(Xapian::Query::OP_OR, 
		    Xapian::Query("three"), 
		    Xapian::Query("four"));
      Xapian::Query near(Xapian::Query::OP_NEAR, or1, or2);

I can't decide by looking at the code in omqueryinternal.cc if this is
intentional or not. In debug mode, it does trigger the NEAR or PHRASE
assertion at the top of flatten_subqs(), which gets called at some point
for the query: 
    ((one NEAR 2 three) OR (one NEAR 2 four))

which does not seem right or needed, 

Is this "(x or y) near (z or t)" query supposed to work or not ? I'm
willing to try and fix it if it should work, but this area of the xapian
code certainly does not suffer from an excess of comments ...

Regards,

J.F. Dockes