On Mon, 30 Apr 2012, Thomas Koch wrote:

Dear Andi, I again had a look at the patch I submitted recently and would like to get back to it. An updated version of the patch is attached to this email - the patch is against the branch_3x repo http://svn.apache.org/repos/asf/lucene/pylucene/branches/branch_3x

Oh, and there is no attachment in your email. Maybe it got eaten up by some mail server. Please, make sure it's of a text mimetype or mail it to me directly.

Thanks !

Andi..


The patch mainly
- adds two java classes:  PythonList,  PythonListIterator
- adds according Python classes   (JavaListIterator and JavaList in 
collections.py)

Purpose:
- provide a Java-based List implementation in JCC/PyLucene (similar to existing 
PythonSet/JavaSet)
- allow to pass python lists via Java Collections into PyLucene

Let's try summarize shortly: PythonSet /JavaSet was already existing, but 
nothing similar for Lists. I made an implementation of PythonList /JavaList and 
with your help this is now basically working. Except of an open issue that 
affects both JavaSet and JavaList: initialization of an ArrayList with a 
JavaSet (or JavaList) may cause trouble.

As you said: "There is a bug somewhere with constructing an ArrayList from a python 
collection like JavaSet or JavaList."

I tried to change the toArray() method as you suggested, but that didn't help. 
As far as I understood, there are two options to box python values into a typed 
JArray:

1)  use the object based JArray class and box python values by wrapping them with the 
corresponding Java object (e.g. type<int> -> lucene.Integer):

x = lucene.JArray('object')([lucene.Boolean(True),lucene.Boolean(False)])
JArray<object>[<Object: true>, <Object: false>]
type(x[0])
<type 'Object'>

2)  use the correct array type (int, float, etc.) and pass the list of Python 
elements or literals) to the JArray constructur, e.g.

y = lucene.JArray('bool')([True,False])
JArray<bool>[True, False]
type(y[0])
<type 'bool'>

I tried both of them (see _pyList2JArray methods in collections.py) but none of 
them did the trick. Actually the 'empty objects in ArrayList' problem remains 
when handling with strings (the ArrayList object that is initialized with a 
JavaSet or JavaList of string items will have a number of objects as the 
original JavaSet/JavaList, but all objects are the same - ooks like an array of 
empty objects). Furthermore another issue with integer lists comes into play: 
here the initialization of  ArrayList with the Collection fails with a Java 
stacktrace (lucene.JavaError: org.apache.jcc.PythonException).

The most simple test case is as follows:

--%< --
import lucene
lucene.initVM()
from lucene.collections import JavaList

# using strings: the ArrayList is created, but initialized with empty objects
jl = JavaList(['a','b'])
al = lucene.ArrayList(jl)
assert (not al.get(0).equals(al.get(1))), "unique values"

# using ints: the ArrayList is not created,  but an error occurs instead:
# Java stacktrace: org.apache.jcc.PythonException: ('while calling toArray')
jl = JavaList(range(3))
al = lucene.ArrayList(jl)
--%< --

I currently feel like having to stab around in the dark to find out what's 
going on here and would welcome any suggestions. Needs some JCC expert I guess 
,-)

Of course we can leave the patch out - but still there's the same issue with 
JavaSet.


kind regards

Thomas
--
OrbiTeam Software GmbH & Co. KG, Germany
http://www.orbiteam.de


-----Ursprüngliche Nachricht-----
Von: Andi Vajda [mailto:[email protected]]
Gesendet: Mittwoch, 18. April 2012 20:37
An: [email protected]
Betreff: Re: AW: PyLucene use JCC shared object by default


Hi Thomas,
...
Lucene 3.6 just got released a few days ago. Apart from your patch, the
PyLucene 3.6 release is ready. I'm about to go offline (email only) for a week.
Let's revisit this patch then (first week of May). It's not blocking the release
right now as, even if I sent out a release candidate for a vote, the three
business days required for this would take this into the time I'm away.
...
Andi..

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