Minor List improvements

[DartBot]

This issue was originally filed by [email protected]

---

The declarations of methods of corelibrary interface List
(http://dart.googlecode.com/svn/trunk/dart/corelib/src/list.dart) have some space for local improvements, w/o seriously affecting semantics.

Below is a list of suggestions, by order of appearance:

1. add(E value) duplicates addLast(E value). It would be more justified if declared as void add(E value, int index); allowing to insert an entry at arbitrary index.

2. indexOf(E element, int startIndex) & lastIndexOf(E element, int startIndex): the last parameter could be optional, with the semantics to search the whole list if omitted (from the list start or list end, respectively).

3. There are removeLast() and last() methods, but no first() and removeFirst() ones. The latter might be unwanted for library design reasons, but it would be more symmetrical to have a first() one?

4. void copyFrom(List<Object> src, int srcStart, int dstStart, int count);
   and
   void setRange(int start, int length, List<E> from, [int startFrom]);
   seem to be close duplicates (except the generic type parameter of the source list). Please clarify the difference in docs or remove one of them (the first?).

[DartBot]

This comment was originally written by [email protected]

---

Thanks Alexey for the feedback! Here's my take on the list:

1. addLast is there because we have removeLast and last. I will document that add and addLast have the same behavior.

2. This has been on my TODO list for a long time, and should be implemented soon.

3. Not that there is no addFirst either. I'm not really fond of adding 'first' methods.

4. Yes, setRange and copyFrom are close duplicates. We plan on removing copyFrom.

---

Set owner to [email protected].
Removed Type-Defect label.
Added Type-Enhancement, Area-Library, Accepted labels.

[DartBot]

This comment was originally written by @mdakin

---

Any plan to add a method for inserting an element to an arbitrary location as mentioned in first item: void add(E value, int index)?

[DartBot]

This comment was originally written by [email protected]

---

One more item, it makes sense to override inherited method filter with covariant return type:
List<E> filter(bool f(E element));

[DartBot]

This comment was originally written by [email protected]

---

comment #­3 is filed as issue #2

[DartBot]

This comment was originally written by [email protected]

---

Set owner to [email protected].
Added Triaged label.

[DartBot]

This comment was originally written by [email protected]

---

I vote for adding addFirst(E value), add(E value, int index), removeFirst() and remove(int index). All these are easy to implement in terms of insertRange(int start, int length, [initialValue]) and removeRange(int start, int length), but just way to cumbersome to repeatedly do in user-code.

[efortuna]

addLast has still never been documented to have the same behavior. Can we add this documentation and/or (better yet) remove addLast? Having both add and addLast simply because we have removeLast and last seems silly.
(+ager since it's a corelib issue?)

---

cc @madsager.

[DartBot]

This comment was originally written by @seaneagan

---

Regarding add/remove, the following scheme would make sense to me:

void addLast(E item);
void addFirst(E item);
void addAt(int index, E item);
E removeLast();
E removeFirst();
E removeAt(int index);

[DartBot]

This comment was originally written by [email protected]

---

Set owner to @lrhn.

[lrhn]

Almost all points here have been addressed now, many in the last library pass. We do not plan to add removeFirst, but we do have removeAt.

---

Added Fixed label.