mutable or immutable features? (was: [Biococoa-dev] Comments on BCAnnotation)

[Koen van der Drift]

On Feb 24, 2005, at 9:57 PM, Charles PARNOT wrote:

> When you modify a sequence, you have to change the positional 
> information in the features. If a feature is mutable, you will want to 
> make a copy first and then modify it, though, because you don't know 
> if the feature instance is not shared with another sequence,

I don't understand this last part. Can you explain why a feature can be 
shared between more than one sequence? The way I see it, if two 
sequences have the same feature they both should have a separate 
BCFeature object to contain that information.

- Koen.