Xapian discuss - May 2004 - Query::Query() in PHP, also QueryParser::prefixes

Just tried to do some query building in PHP but came up against a
brick wall.  The only constructor exposed by SWIG is the first one.
SWIG doesn't seem to support operator overloading of constructors.

I can make a query with one term
    $query1 = new_query("hello");
But trying to build one query from another doesn't work:
    $query = new_query(Query_OP_OR, $query1, $query2);

When building the xapian bindings there are lots of warnings like this:
./../xapian.i:407: Warning(502): Previous declaration is
Xapian::Query::Query(string const &,termcount,termpos)

I've attempted to fix this by modifying xapian.i.  I can't get the
%rename clause to work for a constructor.  I can make another function
which returns  "new Xapian::Query", but I'm worried about memory
leaks since I don't understand how SWIG handles pointers.

Similarly, the member variable QueryParser::prefixes isn't available.
it should probably be a function call anyway.

Either way I'm stuck and will have to resort to piping to Perl again
soon... ;(

Francis
-- 
Undemocratic Europe.  Fix it.  Vote Martin Bell. 
http://www.bellforeurope.org.uk

On Wed, May 26, 2004 at 10:54:35PM +0100, Francis Irving wrote:
> Just tried to do some query building in PHP but came up against a
> brick wall.  The only constructor exposed by SWIG is the first one.
> SWIG doesn't seem to support operator overloading of constructors.
It doesn't for PHP4, no. We have a plan to resolve this (and hence make
the PHP4 bindings more useful).
 
> I've attempted to fix this by modifying xapian.i.  I can't get the
> %rename clause to work for a constructor.
It's now called %name, I think. I've managed to get it working for
constructors in the past, but admittedly not for a while.
> I can make another function which returns "new Xapian::Query",
but
> I'm worried about memory leaks since I don't understand how SWIG
> handles pointers.
"Magically".
 
> Similarly, the member variable QueryParser::prefixes isn't available.
> it should probably be a function call anyway.
No, it's fine as a member. I'm having a quick (modulo recompile time,
sigh) play to see if this can be wrapped conveniently, along with the
other missing bits of the interface.
 
> Either way I'm stuck and will have to resort to piping to Perl again
> soon... ;(
Eww. You may be able to do something with the query server that
Richard put into CVS a while back - don't know quite what state it's
in, though.

J

-- 
/--------------------------------------------------------------------------\
  James Aylett                                                  xapian.org
  james@tartarus.org                               uncertaintydivision.org

On Fri, May 28, 2004 at 11:34:24AM +0100, James Aylett
wrote:
> On Fri, May 28, 2004 at 08:46:43AM +0100, Francis Irving wrote:
> 
> > This line:
> >         $query = new_QueryCombine(Query_OP_AND, $query1, $query2);
> > Gives this error:
> >     Fatal error: Call to undefined function: new_querycombine()
> > 
> > No other function with the word combine appears in the PHP function
> > list either.
> 
> Hmm. What version of SWIG are you using?
owl:~$ swig -version

SWIG Version 1.3.21
Copyright (c) 1995-1998
University of Utah and the Regents of the University of California
Copyright (c) 1998-2003
University of Chicago
Compiled with g++ [i686-pc-linux-gnu]

Please see http://www.swig.org for reporting bugs and further information
owl:~$ dpkg -s swig
Package: swig
Status: install ok installed
Priority: optional
Section: interpreters
Installed-Size: 2748
Maintainer: Torsten Landschoff <torsten@debian.org>
Source: swig1.3
Version: 1.3.21-5
Replaces: swig1.3
Depends: libc6 (>= 2.3.2.ds1-4), libgcc1 (>= 1:3.3.3-1), libstdc++5 (>=
1:3.3.3-1), libswig1.3.21
Suggests: swig-examples, swig-doc
Description: Generate scripting interfaces to C/C++ code
 SWIG is a compiler that makes it easy to integrate C and C++ code
 with other languages including Perl, PHP, Tcl, Ruby, Python, Java,
 Guile, Mzscheme, Chicken, Ocaml, Pike, and C#.
 .
 Swig takes a set of ANSI C/C++ declarations and generates an
 interface for them to your favorite scripting language.

Francis

----- Original Message ----- 
From: "Francis Irving" <francis@flourish.org>
To: <xapian-discuss@lists.xapian.org>
Sent: Wednesday, May 26, 2004 10:54 PM
Subject: [Xapian-discuss] Query::Query() in PHP, also QueryParser::prefixes

> Just tried to do some query building in PHP but came up against a
> brick wall.  The only constructor exposed by SWIG is the first one.
> SWIG doesn't seem to support operator overloading of constructors.
If you use swig tricks (and I forget what they are now) to give the
overloaded constructors different names, swig will still realise they are
constructors and you can invoke them as class methods in php

$new_object=Class::renamed_constructor("blah");

and still get a new instance.

I made it support the default constructor as a class method that returns a
new instance.

Sam