:)

I like this idea of immutability.

Stef

> Hello
>
> I'm reading newspeak spec and I like the idea of immutable strings.
> Now what does it really bring to us?
>
> Safety.  One can no longer overwrite literals or methods (or  
> anything else whose state you want to protect) accidentally.
>
> Expressive power.  One can use immutability as a write barrier in  
> orthogonal persistence or distribution schemes (and other things) .   
> One marks an object as immutable to indicate that it is persistent  
> or distributed and its changes should be exported.  The immutability  
> scheme allows one to associate managers for specific objects that  
> handle NoModificationErrors on a per-object basis.  So if an object  
> is immutable and has an appropriate manager that manager can  
> temporarily enable immutablity for the object, allow the  
> modification, communicate the modification (e.g. to a database or  
> remote image) and then re-enable immutability.  The framework allows  
> an object to have multiple managers.  (This is all standard Squeak  
> and very similar to the code I wrote for VW.  The VM code is also  
> available from Cadence).
>
> Then does it mean that we could get rid of symbols
> immutability does not imply unique identity.
>
> No.  As you point out Symbols are unique and so immutable strings  
> don't replace them.  But it is nice to have immutable Symbols.  e.g.  
> try to do this in your Squeak image:
>     #class pvtAt: 1 put: 0 asCharacter
> Scary :)
>
>
>
> Stef
>
>
>