RE: Mutable Bytes

> I'm not up-to-date on all the arguments pro and con on 
> immutability for text strings, but I'm not sure I see any 
> difference between text strings and binary strings. 

I just realized that I'm leaving out the obvious difference you pointed out
of dictionary keys.  I'm so focused on the implementation differences that I
forgot the big usage difference.

Immutability is a big deal internally in terms of efficiency. Immutable
objects don't have to be locked and they cause less problems in a lot of
respects.

But I do understand your point about not needing their immutability for
dictionary keys.

Can we get some other comments on this?