Modify API of candidates().

Modify API of candidates().

This CL changes API only.
Internal behavior will be changed in another CL.

BUG=None
TEST=Run a test

[Peng, 2011-11-30 16:49:44]

http://codereview.appspot.com/5437086/diff/1/src/PyZyInputContext.h
File src/PyZyInputContext.h (right):

http://codereview.appspot.com/5437086/diff/1/src/PyZyInputContext.h#newcode43
src/PyZyInputContext.h:43: class Candidates {
Any reason we need make it as an abstract interface instead of implementing an
Candidates class directly?

[hsumita, 2011-11-30 17:35:18]

I think it is better because we can hide the details of implementation (e.g.
private member functions/variables).
It is also acceptable that we use pimple idiom.

Which do you think better? Or do you have any other solutions?

[Peng, 2011-11-30 17:56:27]

On 2011/11/30 17:35:18, hsumita wrote:
> I think it is better because we can hide the details of implementation (e.g.
> private member functions/variables).
> It is also acceptable that we use pimple idiom.
> 
> Which do you think better? Or do you have any other solutions?

I think using virtual functions is a little expensive, if it is only for hiding
implementation detail and private data. You may check some Qt code, it uses a
different way to hide implementation and private data.

http://qt.gitorious.org/qt/qt/blobs/4.7/src/corelib/io/qfile.h
http://qt.gitorious.org/qt/qt/blobs/4.7/src/corelib/io/qfile_p.h

Anyway, It is not a high priority issue, you may check in it now, and we could
refactor it later.

LGTM.

[hsumita, 2011-12-01 02:24:26]

Thank you for your suggestion!
I will refactor it later.

submitting...