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From nitin mahendru <nitin.mahendr...@gmail.com>
Subject Re: [CSV] CSVMutableRecord
Date Mon, 21 Aug 2017 21:51:21 GMT
Just another follow up. Anything new ?

-Nitin




On Thu, Aug 17, 2017 at 10:58 AM Gary Gregory <garydgregory@gmail.com>
wrote:

> Not yet ;-)
>
> On Aug 17, 2017 11:34, "nitin mahendru" <nitin.mahendru88@gmail.com>
> wrote:
>
> > Hi All,
> >
> > Any consensus on this ?
> >
> > -Nitin
> >
> >
> >
> >
> > On Tue, Aug 15, 2017 at 4:43 PM Gary Gregory <garydgregory@gmail.com>
> > wrote:
> >
> > > On Tue, Aug 15, 2017 at 5:32 PM, Gilles <gilles@harfang.homelinux.org>
> > > wrote:
> > >
> > > > On Tue, 15 Aug 2017 22:52:32 +0000, nitin mahendru wrote:
> > > >
> > > >> On Tue, 15 Aug 2017 12:02:20 -0600, Gary Gregory wrote:
> > > >>
> > > >>> On Tue, Aug 15, 2017 at 10:38 AM, nitin mahendru
> > > >>> <nitin.mahendru88@gmail.com
> > > >>>
> > > >>>> wrote:
> > > >>>>
> > > >>>
> > > >>> How about having a state in the class itself which says that it's
> > > >>>> mutable
> > > >>>> or not.
> > > >>>> If we call a setter on an immutable then it throws an exception.
> > > >>>> By default the records are immutable and you need to make
them
> > > >>>> mutable
> > > >>>> using a new API.
> > > >>>>
> > > >>>
> > > >> A code example would be useful...
> > > >>
> > > >>
> > > >>
> > > >>
> > > >> Below is the pull request I added.
> > > >> https://github.com/apache/commons-csv/pull/21
> > > >>
> > > >
> > > > As I indicated in the previous message, this is functionally
> > > > breaking. [I'm diverting this discussion over to the "dev"
> > > > mailing list.]
> > > >
> > >
> > > Saying that making record mutable is "breaking" is a bit unfair when we
> > do
> > > NOT document the mutability of the class in the first place.
> > >
> > > Gary
> > >
> > >
> > > >
> > > > The following should be an interesting read:
> > > >   http://markmail.org/message/6ytvmxvy2ndsfp7h
> > > >
> > > >
> > > > Regards,
> > > > Gilles
> > > >
> > > >
> > > >
> > > >
> > > >> On Tue, Aug 15, 2017 at 11:17 AM Gilles <
> gilles@harfang.homelinux.org
> > >
> > > >> wrote:
> > > >>
> > > >> On Tue, 15 Aug 2017 12:02:20 -0600, Gary Gregory wrote:
> > > >>> > On Tue, Aug 15, 2017 at 10:38 AM, nitin mahendru
> > > >>> > <nitin.mahendru88@gmail.com
> > > >>> >> wrote:
> > > >>> >
> > > >>> >> How about having a state in the class itself which says
that
> it's
> > > >>> >> mutable
> > > >>> >> or not.
> > > >>> >> If we call a setter on an immutable then it throws an
exception.
> > > >>> >> By default the records are immutable and you need to
make them
> > > >>> >> mutable
> > > >>> >> using a new API.
> > > >>>
> > > >>> A code example would be useful...
> > > >>>
> > > >>> >> pros: Saves memory, Keeps the immutability benefits
> > > >>>
> > > >>> What kind of usage are you considering that a single transient
> > > >>> record matters (as compared to the ~300 MB of the JVM itself...)?
> > > >>>
> > > >>> >> cons: people using "mutable" records need to be careful.(While
> > > >>> >> threading
> > > >>> >> maybe)
> > > >>> >>
> > > >>> >
> > > >>> > Interesting idea!
> > > >>> >
> > > >>> > But I think I like the idea of a subclass better if we are
going
> to
> > > >>> > split
> > > >>> > the behavior b/w mutable and immutable.
> > > >>>
> > > >>> Once you have a subclass that is able to modify the state of
> > > >>> its parent, it's a mutable object. Period.
> > > >>> There is no such thing as a "split".
> > > >>>
> > > >>> >
> > > >>> > For my money and the KISS principle, I would just add the
put
> > method
> > > >>> > in
> > > >>> > CSVRecord.
> > > >>>
> > > >>> Then, any use that assumes immutability will be broken.
> > > >>>
> > > >>>
> > > >>> Gilles
> > > >>>
> > > >>>
> > > >>> > Gary
> > > >>> >
> > > >>> >>
> > > >>> >> -Nitin
> > > >>> >>
> > > >>> >>
> > > >>> >>
> > > >>> >>
> > > >>> >> On Tue, Aug 15, 2017 at 9:01 AM Gilles
> > > >>> >> <gilles@harfang.homelinux.org>
> > > >>> >> wrote:
> > > >>> >>
> > > >>> >> > On Tue, 15 Aug 2017 09:49:04 -0600, Gary Gregory
wrote:
> > > >>> >> > > That looks odd to me. What comes up for me
is the use case
> > where
> > > >>> >> I
> > > >>> >> > > want to
> > > >>> >> > > ETL a file of 10,000,000 records and update,
say, one
> column.
> > If
> > > >>> >> am
> > > >>> >> > > forced
> > > >>> >> > > to create a brand new record for every record
read, that
> would
> > > >>> >> be a
> > > >>> >> > > shame.
> > > >>> >> >
> > > >>> >> > Why?
> > > >>> >> >
> > > >>> >> > > If I had a mutable record, I could just keep
on updating it
> > and
> > > >>> >> using
> > > >>> >> > > it to
> > > >>> >> > > write each row. Read record, update it, write
record. No
> extra
> > > >>> >> memory
> > > >>> >> > > needed.
> > > >>> >> >
> > > >>> >> > How is the size of 1 additional record going to
matter
> compared
> > to
> > > >>> >> the
> > > >>> >> > size of the whole program?
> > > >>> >> >
> > > >>> >> > > Either we can make the current record mutable
(what's the
> > harm?)
> > > >>> >> or
> > > >>> >> > > we can
> > > >>> >> > > make the parser serve out mutable records based
on a config
> > > >>> >> setting.
> > > >>> >> > > This
> > > >>> >> > > could be a subclass of CSVRecord with the extra
method I
> > > >>> >> proposed.
> > > >>> >> >
> > > >>> >> > The harm is that you loose all the promises of immutability.
> > > >>> >> >
> > > >>> >> > Regards,
> > > >>> >> > Gilles
> > > >>> >> >
> > > >>> >> > >
> > > >>> >> > > Thoughts?
> > > >>> >> > >
> > > >>> >> > > Gary
> > > >>> >> > >
> > > >>> >> > > On Tue, Aug 15, 2017 at 8:33 AM, Gilles
> > > >>> >> > > <gilles@harfang.homelinux.org>
> > > >>> >> > > wrote:
> > > >>> >> > >
> > > >>> >> > >> On Tue, 15 Aug 2017 08:01:53 -0600, Gary
Gregory wrote:
> > > >>> >> > >>
> > > >>> >> > >>> How does that work when you want to
change more than one
> > > >>> >> value?
> > > >>> >> > >>>
> > > >>> >> > >>
> > > >>> >> > >> How about a "vararg" argument:
> > > >>> >> > >>
> > > >>> >> > >> /**
> > > >>> >> > >>  * @param orig Original to be copied.
> > > >>> >> > >>  * @param replace Fields to be replaced.
> > > >>> >> > >>  */
> > > >>> >> > >> public static CSVRecord createRecord(CSVRecord
orig,
> > > >>> >> > >>                                      Pair<Integer,
String>
> > ...
> > > >>> >> > >> replace) {
> > > >>> >> > >>     // ...
> > > >>> >> > >> }
> > > >>> >> > >>
> > > >>> >> > >>
> > > >>> >> > >> Gilles
> > > >>> >> > >>
> > > >>> >> > >>
> > > >>> >> > >>
> > > >>> >> > >>> Gary
> > > >>> >> > >>>
> > > >>> >> > >>> On Aug 15, 2017 00:17, "Benedikt Ritter"
<
> > britter@apache.org>
> > > >>> >> > >>> wrote:
> > > >>> >> > >>>
> > > >>> >> > >>> Hi,
> > > >>> >> > >>>>
> > > >>> >> > >>>> I very much like that CSVRecord
is unmodifiable. So I’d
> > > >>> >> suggest an
> > > >>> >> > >>>> API,
> > > >>> >> > >>>> that creates a new record instead
of mutating the
> existing
> > > >>> >> one:
> > > >>> >> > >>>>
> > > >>> >> > >>>> CSVRecord newRecord = myRecord.put(1,
„value")
> > > >>> >> > >>>>
> > > >>> >> > >>>> I’m not sure about „put“
as a method name since it
> clashes
> > > >>> >> with
> > > >>> >> > >>>> java.util.Map#put, which is mutation
based...
> > > >>> >> > >>>>
> > > >>> >> > >>>> Regards,
> > > >>> >> > >>>> Benedikt
> > > >>> >> > >>>>
> > > >>> >> > >>>> > Am 15.08.2017 um 02:54 schrieb
Gary Gregory
> > > >>> >> > >>>> <garydgregory@gmail.com>:
> > > >>> >> > >>>> >
> > > >>> >> > >>>> > Feel free to provide a PR
on GitHub :-)
> > > >>> >> > >>>> >
> > > >>> >> > >>>> > Gary
> > > >>> >> > >>>> >
> > > >>> >> > >>>> > On Aug 14, 2017 15:29, "Gary
Gregory"
> > > >>> >> <garydgregory@gmail.com>
> > > >>> >> > >>>> wrote:
> > > >>> >> > >>>> >
> > > >>> >> > >>>> >> I think we've kept the
design as YAGNI as possible...
> > :-)
> > > >>> >> > >>>> >>
> > > >>> >> > >>>> >> Gary
> > > >>> >> > >>>> >>
> > > >>> >> > >>>> >> On Mon, Aug 14, 2017 at
3:25 PM, nitin mahendru <
> > > >>> >> > >>>> >> nitin.mahendru88@gmail.com>
wrote:
> > > >>> >> > >>>> >>
> > > >>> >> > >>>> >>> Yeah that also is
OK. I though there is a reason to
> > keep
> > > >>> >> the
> > > >>> >> > >>>> CSVRecord
> > > >>> >> > >>>> >>> without setters. But
maybe not!
> > > >>> >> > >>>> >>>
> > > >>> >> > >>>> >>> Nitin
> > > >>> >> > >>>> >>>
> > > >>> >> > >>>> >>>
> > > >>> >> > >>>> >>>
> > > >>> >> > >>>> >>>
> > > >>> >> > >>>> >>> On Mon, Aug 14, 2017
at 2:22 PM Gary Gregory
> > > >>> >> > >>>> <garydgregory@gmail.com
> > > >>> >> > >>>> >
> > > >>> >> > >>>> >>> wrote:
> > > >>> >> > >>>> >>>
> > > >>> >> > >>>> >>>> Hi All:
> > > >>> >> > >>>> >>>>
> > > >>> >> > >>>> >>>> Should we consider
adding put(int,Object) and
> > > >>> >> put(String,
> > > >>> >> > >>>> Object) to
> > > >>> >> > >>>> the
> > > >>> >> > >>>> >>>> current CSVRecord
class?
> > > >>> >> > >>>> >>>>
> > > >>> >> > >>>> >>>> Gary
> > > >>> >> > >>>> >>>>
> > > >>> >> > >>>> >>>> On Mon, Aug 14,
2017 at 2:54 PM, nitin mahendru <
> > > >>> >> > >>>> >>>> nitin.mahendru88@gmail.com>
> > > >>> >> > >>>> >>>> wrote:
> > > >>> >> > >>>> >>>>
> > > >>> >> > >>>> >>>>> Hi Everyone,
> > > >>> >> > >>>> >>>>>
> > > >>> >> > >>>> >>>>> I recently
pushed a change(pull request 20) to get
> > the
> > > >>> >> line
> > > >>> >> > >>>> ending
> > > >>> >> > >>>> >>> from
> > > >>> >> > >>>> >>>> the
> > > >>> >> > >>>> >>>>> parser.
> > > >>> >> > >>>> >>>>>
> > > >>> >> > >>>> >>>>> Now I want
to push another change which I feel will
> > > >>> >> also be
> > > >>> >> > >>>> useful
> > > >>> >> > >>>> for
> > > >>> >> > >>>> >>>> the
> > > >>> >> > >>>> >>>>> community.
I want to add a CSVRecordMutable class
> > which
> > > >>> >> had
> > > >>> >> > >>>> a
> > > >>> >> > >>>> >>> constructor
> > > >>> >> > >>>> >>>>> which accepts
a CSVRecord object. So when we have a
> > > >>> >> > >>>> CSVRecordMutable
> > > >>> >> > >>>> >>>> object
> > > >>> >> > >>>> >>>>> from it then
we can edit individual columns using
> it.
> > > >>> >> > >>>> >>>>>
> > > >>> >> > >>>> >>>>> I would be
using this to write back my edited CSV
> > file.
> > > >>> >> My
> > > >>> >> > >>>> use case
> > > >>> >> > >>>> >>> is to
> > > >>> >> > >>>> >>>>> read a csv,
mangle some columns, write back a new
> > csv.
> > > >>> >> > >>>> >>>>>
> > > >>> >> > >>>> >>>>> I could have
directly raised a pull request but I
> > just
> > > >>> >> > >>>> wanted to
> > > >>> >> > >>>> float
> > > >>> >> > >>>> >>>> the
> > > >>> >> > >>>> >>>>> idea before
and see the reaction.
> > > >>> >> > >>>> >>>>>
> > > >>> >> > >>>> >>>>> Thanks
> > > >>> >> > >>>> >>>>>
> > > >>> >> > >>>> >>>>> Nitin
> > > >>> >> > >>>> >>>>>
> > > >>> >> > >>>> >>>>
> > > >>> >> > >>>> >>>
> > > >>> >> > >>>> >>
> > > >>> >> > >>>> >>
> > > >>> >> > >>>>
> > > >>> >> > >>>>
> > > >>> >> > >>>>
> > > >>> >> > >>
> > > >>>
> > > >>>
> > > >>>
> > > >>> ------------------------------------------------------------
> > ---------
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> > > >>> For additional commands, e-mail: user-help@commons.apache.org
> > > >>>
> > > >>>
> > > >>>
> > > >
> > > > ---------------------------------------------------------------------
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> > > >
> > > >
> > >
> >
>

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