"Lukas Renggli" <renggli at gmail.com> writes:
> > Also, FWIW, if you like the ANSI version, it is easy to implement.
> > Here is a version using a dead forked dialect of Squeak; it should be
> > easy to dust it off should anyone want.  This version goes further
> > than discussed in this thread, and even makes floats and large integers
> > be immutable.  :)  The code is in islands.zip on the following page;
> > look inside the zip for immutLits1.5.cs and immutLits2.2.cs.
> >
> >   http://wiki.squeak.org/squeak/2074
> 
> In 3.8 and 3.9 there are 5 subclasses of String (Symbol, Byte and
> Wide) and many more for ArrayedCollection. Your change would introduce
> many read-only classes and lead to much duplicated code (ok, traits
> would be a big help here).
> 
> Immutability should be an instance-level property and not special
> class. 


Good point, there was just one String back then so it was simpler.

Still, there should be a reasonable way to engineer this at the image
level.  Smalltalk is a pretty cool language.  :) And adding immutable
strings and arrays, should be easier than adding a generic
immutability system.

A generic immutability system would be cool, though.  You could catch
some bugs with it.


-Lex