Slate has this. &foo: arguments specify optional named arguments for 
methods and blocks, and *rest parameters allow you to grab any 
"run-over" arguments to a block or method in an array.

And of course, being dynamic, you can add and remove slots to anything 
allowable.

We're still working on the Squeak-1.0 level of support, but the basics 
all work well. We even recently have incorporated some of the 
Squeak-Traits research work to make our mixins safer.

On Nov 18, 2004, at 1:08 PM, stéphane ducasse wrote:

> variable length argument methods
> and default argument values
>
> because this would be really cool to have that in Squeak.
> Ok of course this change the language but we could get rid of a lot of 
> with:with:with: methods.
>
>
> I also thought recently that something really missing in Smalltalk is
> dictionary like classes
> 	because we have named fixed attributes, variables unamed attributes
> 	but often I would like to have variables (dictionary-based) 
> attributes.
>
> Stef
--
Brian T. Rice
LOGOS Research and Development
http://tunes.org/~water/