Hi Gilles! Sorry, just came back from a long holiday, speaking Portuguese only. Semantic, vocabulary, etc, in English is a bit laggy right now.
>>On Tue, 18 Dec 2018 07:22:00 +0000 (UTC), Bruno P. Kinoshita wrote: >> From what I understood from the previous messages & discussion on >> GitHub, it would be more convenient for users to be able to have a >> List instead of an Iterable, > >Why "instead"? >The patch makes the class a subclass of "List"; and "List" >implements "Iterable". That's right, I meant to say that it would be an AbstractList, and not only an Iterable any more. >> However, I think we are delivering an Iterable that's fully capable >> to be used as an Iterable now. Whereas the proposal would make it a >> read-only list, as that returned from unmodifiableList, > >That's not what the patch does: >https://docs.oracle.com/javase/7/docs/api/java/util/AbstractList.html I think tis another semantic/communication issue. From the link above: "Note that this implementation throws an UnsupportedOperationException unless remove(int index) or removeRange(int fromIndex, int toIndex) is overridden." That's what I meant. By extending AbstractList, users could now call remove and other methods, that would result in the exception above (similarly to the list returned via Collections.unmodifiableList). >How? >[In the original code, "toList" is private.] Oh, good point!!! I wrote the e-mail from memory, a few days after reading the code, and after just arriving at home. Mea culpa. >> by accidentally >> trying to reuse CSVRecord while reading from one input and writing to >> an output stream. > >I don't understand this. That was a contrived example. Say you read the records, transform the Iterable into a List, and add/remove/clear columns/rows while processing the CSVRecord (e.g. you could be using commons-text and other libs to filter/process the entries). Then you get these values and create a new CSV. When users realize they now have a List instead, they could rely on the CSVRecord object, instead of creating new Lists, and get some runtime errors. Corner case, and - again - a contrived example. But I'm not opposing the change, just don't see the need for using AbstractList (though I've been writing Python for the past couple of months, so my Java-fu isn't really sharp right now). Cheers Bruno ________________________________ From: Gilles <gil...@harfang.homelinux.org> To: dev@commons.apache.org Sent: Wednesday, 19 December 2018 1:28 AM Subject: Re: [CSV] Records as Lists Hi. On Tue, 18 Dec 2018 07:22:00 +0000 (UTC), Bruno P. Kinoshita wrote: > From what I understood from the previous messages & discussion on > GitHub, it would be more convenient for users to be able to have a > List instead of an Iterable, Why "instead"? The patch makes the class a subclass of "List"; and "List" implements "Iterable". > or instead of having to call the > #toList() or convert to a List in some other way. > I commented in the pull request, that I don't think there would be a > performance penalty in doing so (at least I don't think so, as the > values are not streamed, but rather kept in the private values > array). > However, I think we are delivering an Iterable that's fully capable > to be used as an Iterable now. Whereas the proposal would make it a > read-only list, as that returned from unmodifiableList, That's not what the patch does: https://docs.oracle.com/javase/7/docs/api/java/util/AbstractList.html > i.e. throwing > exceptions for add/clear/etc operations. The original code (using "Arrays.asList") could not do those operations: https://docs.oracle.com/javase/7/docs/api/java/util/Arrays.html#asList(T...) > In my opinion, I prefer to keep it as an Iterable, leave the toList > method, as I think current users could be affected How? [In the original code, "toList" is private.] > by accidentally > trying to reuse CSVRecord while reading from one input and writing to > an output stream. I don't understand this. Regards, Gilles > So I'm -0 for it. > Bruno > > From: sebb <seb...@gmail.com> > To: Commons Developers List <dev@commons.apache.org> > Sent: Tuesday, 18 December 2018 12:24 AM > Subject: Re: [CSV] Records as Lists > > What is the use-case for using lists? > > On Thu, 13 Dec 2018 at 18:34, Gary Gregory <garydgreg...@gmail.com> > wrote: >> >> Hi All, >> >> I am looking for opinions on turning a CSV record into a list, as >> opposed >> to the minimal current implementation. There would be side-effects >> like a >> record becoming writable instead of read-only as the current >> implementation. >> >> Memory footprint would also be a concern. >> >> Please see https://github.com/apache/commons-csv/pull/35 >> >> Gary > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org > For additional commands, e-mail: dev-h...@commons.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org For additional commands, e-mail: dev-h...@commons.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org For additional commands, e-mail: dev-h...@commons.apache.org
