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
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..
