List Behavior when inserting new items

[Drew]

> What is your actual usecase?
>
> diez

The issue is that I don't know how long the list will eventually be. 
Essentially I'm trying to use a 2D list to hold lines that I will 
eventually print to the screen. Blank elements in the list will be 
printed as spaces. I suppose every time I add an element, I could find 
the difference between the size of the list and the desired index and 
fill in the range between with " " values, however I just wanted to 
see if there was a more natural way in the language.

Thanks,
Drew