Lists.charactersOf(CharSequence), returning List<Character> about guava

[gissuebot]

Original comment posted by gonzaloaune on 2007-11-19 at 03:37 PM

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You want to get a list of characters specified in the CharSequence of a certain List
right?.

[gissuebot]

Original comment posted by gonzaloaune on 2007-11-19 at 03:39 PM

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Like... List.charactersOf(List<String>, charSequence) ?

[gissuebot]

Original comment posted by kevinb9n on 2007-11-19 at 06:06 PM

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No, just view a CharSequence as a List, for example Lists.charactersof("abc") returns
['a', 'b', 'c'].

[gissuebot]

Original comment posted by gonzaloaune on 2007-11-19 at 07:15 PM

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You can use something like that (sorry for my english) =), im just trying to help.

Regards!

  /**
   * Returns an {@code List} instance given the charSequence.
   *
   * @param charSequence the elements that the list should contain, in order.
   * @return an {@code List} instance containing those elements.
   * */
  public static List<CharSequence> charactersOf(CharSequence charSequence) {
    checkNotNull(charSequence);
    List<CharSequence> charsList = newArrayList();

for (int i = 0; i < charSequence.length(); i++) {
  charsList.add(charSequence.subSequence(i, i+1));
}

return charsList;

  }

[gissuebot]

Original comment posted by gonzaloaune on 2007-11-20 at 02:20 PM

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Also, we could add this validation to avoid the creation of the new list.

if (charSequence.length() == 0) {
  return null; //Or whatever you want... (emptyList?)
}

Regards!

[gissuebot]

Original comment posted by mohammady.mahdy on 2009-05-04 at 07:57 AM

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I implemented this as a view of the character sequence in the attached patch, I'd
really appreciate any review and comment on it even if its not included as this is
one of my very first open source contributions.

[gissuebot]

Original comment posted by creswick on 2009-05-04 at 05:47 PM

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I took a quick look over charctersOf.txt, and have a few questions/suggestions. I
don't have the experience to comment on the overall structure/approach, but hopefully
these comments are helpful:

   * There is no guarantee that a given CharSequence is immutable, and it looks like
subSequence(int, int) returns a copy, rather than a view, so the implementation of
CharSequenceListView.subList(int,int) may not maintain the contract specified in the
List api for subList(int,int). (This can be seen by using subSequence and delete on
a StringBuffer.)

   * Is it necessary to redefine add/addAll/remove/set given that
CharSequenceListView extends ImmutableCollection<Character>?

   * Should the overridden methods all have @Overrides annotations? (get/add/etc.)

   * I believe all the fields could be final.

   * @NonNull annotation on parameter of charactersOf(CharSequence)?

   * javadoc on charactersOf(CharSequence)

   * Would it make sense to have the ListIterator extend
     UnmodifiableIterator? (reusing the remove() method defined
     therin). It seems like what you want is an
     UnmodifiableListIterator, which doesn't seem to exist yet.

[gissuebot]

Original comment posted by mohammady.mahdy on 2009-05-05 at 06:36 AM

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thanks for taking time to read the code and comment :-), ok here goes:
1-you are absolutely right, i will rewrite the sublist function to view the same list
probably with start and end fields limiting the operations and altering the behavior
of the iterators.

2-yes in case i am extending ImmutableCollection, I should've extended ImmutableList
though.

3-you are absolutely right I should do that.

4-you are right.

5-sure I just wrote the code as a draft to get feedback about the approach.

6-ya I looked for an UnmodifiableListIterator but couldn't find any and found myself
asking the same question and decided to do it the direct way and just change it if
there was a good reason.

I also figured out a better way to do the iterators (make them fail by saving the
initial size and checking the current size each time instead of iterate on a copy,
thanks for pointing out that subsequence returns a copy not a view, this won't detect
any set kind of operations though -- any ideas ?).

[gissuebot]

Original comment posted by mohammady.mahdy on 2009-05-05 at 11:18 AM

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if i actually viewed the list with start and end fields how would i know if the
sequence has changed and that these fields should be updated?

[gissuebot]

Original comment posted by kevinb9n on 2009-09-17 at 06:02 PM

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(No comment entered for this change.)

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Labels: Milestone-Post1.0

[gissuebot]

Original comment posted by finnw1 on 2010-02-01 at 03:03 PM

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Wouldn't com.google.common.primitives.Chars be a better place for this than
com.google.common.collect.Lists, e.g. an overload of Chars.asList()?

[gissuebot]

Original comment posted by [email protected] on 2010-07-30 at 03:53 AM

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(No comment entered for this change.)

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Labels: -Milestone-Post1.0

[gissuebot]

Original comment posted by [email protected] on 2010-07-30 at 03:56 AM

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(No comment entered for this change.)

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Labels: -Priority-Medium

[gissuebot]

Original comment posted by [email protected] on 2010-09-14 at 08:49 PM

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(No comment entered for this change.)

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Status: Fixed
Owner: [email protected]
Labels: Milestone-Release07