> I took a quick look in FunSqueak, I'll have to take a deeper look when I get
> a minute.  Two questions:
> * does it address the debuggability issue Bert mentioned for blocks?

If you're caught in the debugger while the LMS block fails, no. But 
since the structure of that block is exposed via the LMS, it is possible 
to debug by erasing all compiled forms in the suspected code and see the 
same error that was in the block appear within the evaluation of the 
original LMS. Don't know if I'm being clear here.

> * can it have state?

Yes, via default values stored in LambdaSlots. Look in the class-side of 
NFunction for examples, like:

-----------------
hyperbolicDamping

  | decayRate |

  decayRate _ Lambda scale default: 1; description: 'x scaling'; type: 
NumericSlot.

  ^ (Lx abs /// decayRate + 1) reciprocal
-----------------


In that code, decayRate is a lambda slot whose default gives the 
returned LMS state:


NFunction hyperbolicDamping
  -->
  Lx.Lscale.{((<x> abs /// <scale>) + 1) reciprocal}


NFunction hyperbolicDamping defaultForm
  -->
  Lx.{((<x> abs /// 1) + 1) reciprocal}


(NFunction hyperbolicDamping parametrize: #scale default: 42) defaultForm
  -->
  Lx.{((<x> abs /// 42) + 1) reciprocal}


This is a step away from pure functional programming but it is very 
useful in practice.

muO has lots of examples of LMS usage; if you want to explore them get 
the ready-to-go image at
http://www.zogotounga.net/comp/squeak/muo/muO%20257%20image.zip


best,

Stef