[Biococoa-dev] mutable sequences

[Koen van der Drift]

Hi,

I hope everyone is enjoying a nice summer.

A main part of the app I am developing is a sequence editor.  
Basically it is a subclass of NSTextView that displays the string  
obtained from a BCSequence object. Since right now BCSequence is an  
immutable object, I am wondering what would be a good strategy to  
implement the editing. One possibility that comes to mind is  
everytime that the user edits the sequence (observed by a  
textDidChange notification from the textview), I recreate the  
BCSequence object and swap it with the current one. The nice thing  
about this is that it allows live editing, so characteristics of the  
sequence can be updated while typing (maybe even using bindings?).  
The negative part, of course is that after each keystroke (or  
actually after each notification) I need to create a new sequence  
object from an NSString, which can be costly, and/or slow things down.

So an alternative solution could be using a mutable BCSequence  
object, and then just add/remove the BCSymbols corresponding to the  
keystrokes. I remember that Alex and Charles have been talking/ 
chatting about a mutable sequence object, but I did not really follow  
that discussion. What is the current thought about mutable sequences,  
and how could it be implemented into BioCocoa?

cheers,

- Koen.