Hi all,

I am having a strange problem with anonymous blocks.  I have been trying to 
impliment a Reccurrence rule engine.  After trying different implimentations 
I didn't like, I found that the best solution involved an infinite list.  So 
I set out to impliment lazy evaluation in smalltalk.  What I have now works 
like:

((LazyElement enumerateFrom: 2006 with: [:e| e + 2]) collectAndFlatten: [:y|
   (LazyElement fromArray: #(1 8 12)) collectAndFlatten: [:m|
		(LazyElement fromArray: #(1 15 27)) collect: [:d|
        		   Date year: y month: m day: d
			]
       	]
]) take: 500

And this part works perfectly.  I have gone up to 2k dates and I noticed no 
delay at all (though I haven't timed it).  I then changed the List creation 
parts to be methods, which is what my final solution will need.  If I change 
the month function to return different months depending on the year and it 
works perfectly.  But if I have a year for which no months apply and return 
an empty list, I get "error: Attempt to  evaluate a block that is already 
evaluated."

I have done a parralell implimentation in Ocaml (because it also requires me 
to manually build the Lazy List operations) and everything worked as 
expected, so I am really baffelled on this one.  Nothing should be happening 
in the empty list case that doesn't already happen in the case of 1 or more 
in the list.

I read on the list that the solution to this problem is to copy or clone the 
block.  I have put a clone on every place I use a block and it didn't help.  
Nor did copy.

I have enclosed the file out of the Lazy list classes (it's not a lot of 
code), I would appreciate any help anyone could give me.

Thanks,
Jason

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