[stdlib] Add three __delitem__ method overloads for List

[rd4com]

This PR includes three __delitem__ method overloads for List:

• fn __delitem__(inout self, position: Int)
• fn __delitem__(inout self, *positions: Int)
• fn __delitem__(inout self, owned positions: List[Int])

The implementation ensure that an index will not be deleted twice,
even if provided multiple times.
The order of removal is the reverse of sorted indexes.

 

Example:

  x = List[Int](0,10,20,30,40)
  x.__delitem__(0,4)
  for i in x: print(i[]) #10,20,30

 

@rparolin proposed using __delitem__ directly instead of del_batch_of_indexes

Suggestion for the future:

del my_list[0,1,4,5]

[rparolin]

Since we lack the language feature to remove subranges via the del keyword, I propose we implement the __delitem__ member function and call it directly until we land the language feature enabling the use of del. @JoeLoser Thoughts?

[rd4com]

Hello,

new commit changed the method name to __delitem__ and includes an overload that takes only one position as an integer.

That way, it won't create a set and sort an array if there is only one index. ( _ = self.pop(position))

• Should there be any debug_asserts that asserts that len(self) > index and index >= 0 ?

• Should the methods just don't do self.pop(position) if position is out of bound ?