[MLton] regions

[Stephen Weeks]

> > 3. provide the programmer with a way to limit memory usage in the 
> >    case that automation fails.
> 
> ahh, three points for which I will not disagree about. I think, if you want 
> to complain about regions these are the issues to bring up. Safe-for-space 
> satisfies 1 and 2 to a large degree. However, let me point out that 3 
> typically requires adding things like weak references and other "hacks" to 
> deal with things like symbol-tables and the like.

True.  

> BTW does Mlton support weak references? It's been a while since I looked, 
> but I don't remember seeing anything like weak references last I hacked on 
> the MLton GC. :)

They're there.  MLton.Weak and MLton.Finalizable were added in Spring
2003, partially to support mGTK.