[Pythonmac-SIG] self-instantiating instances in pyhton

[Rayme Jernigan]

Hi Benjamin,

I've done this sort of thing with linked lists in Python... by putting 
all the nodes in a (Python) list, each with a unique ID, and using that 
ID to link the nodes to each other, etc. But the important thing for me 
to learn about here... "the goal"...  is the self-instantiation aspect 
of the problem. The R/B tree is just an example I chose to show why you 
might want to so such a silly thing. ;)

Thanks for checking around, though...

On Jan 12, 2005, at 1:03 PM, Schollnick, Benjamin wrote:

> Rayme,
>
> 	This sounds like a Linked List system...
>
> 	I was not able to find quickly a linked list module, but
> 	searching by "trees" at the Vaults produced a R/B tree...
>
> 	http://newcenturycomputers.net/projects/rbtree.html
>
> 	I've been out of touch, I have not heard about the Red/Black
> 	balanced tree algorithm...
>
> 	Hmm...  But take a look and see if it meets your
> 	requirements...
>
> 	But take a look at your implementation, if your just
> 	trying to make a linked list, you could just use a
> 	standard python list....
>
> 			- Benjamin
>
>> -----Original Message-----
>> From: pythonmac-sig-bounces at python.org
>> [mailto:pythonmac-sig-bounces at python.org] On Behalf Of Rayme Jernigan
>> Sent: Wednesday, January 12, 2005 12:53 PM
>> To: pythonmac-sig at python.org
>> Subject: [Pythonmac-SIG] self-instantiating instances in pyhton
>>
>>
>> Hi,
>>
>> I'm looking for a language to abuse for a project I'm working on. I
>> know a little Python, but I do not know if it can do this:
>> I'd like to
>> define some class "N" that instantiates objects that can instantiate
>> fresh new objects of that same class... without external controller
>> code.
>>
>> You could use this capability, for example, to generate a red-black
>> tree-type data structure that implicitly instantiates a new node for
>> each new input d1, d2, d3... so on. The algorithm for each node could
>> be:
>>
>> -- Toggle downstream L/R pointer
>> -- If no node there, instantiate one and link to it
>> -- if a node is there, pass the datum to it
>>
>> The execution sequence as the tree builds itself out might look
>> something like this:
>>
>> 1. n0 = N(d0)	# new instance of N
>> 			# (downstream pointer default = "Left")
>> 			# (the first input data, d0, is
>> instantiated in node n0)
>> 			# nodes: n0
>>
>> 2. n0.send(d1) 	# toggle n0's downstream pointer to "Right"
>> 			# on n0 there is no downstream node
>> right so instantiate a new
>> linked node right n1 with d1
>> 			# nodes: n0,n1
>>
>> 3. n0. send(d2) # toggle n0's downstream pointer "Left"
>> 			# in n0 there is no downstream node
>> left so instantiate n2 with d2
>> 			# nodes: n0,n1,n2
>>
>> 4. n0. send(d3) # toggle n0's downstream pointer "Right"
>> 			# there exists a downstream node right,
>> n1, so send d3 there
>> 			# toggle n1's downstream pointer "Right"
>> 			# in n1 there is no downstream node
>> right so instantiate n3 with d3
>> 			# nodes: n0,n1,n2,n3
>>
>> 5. n0. send(d4) # toggle n0's downstream pointer "Left"
>> 			# there exists a downstream node left,
>> n2, so send d4 there
>> 			# toggle n2's downstream pointer "Right"
>> 			# in n2 there is no downstream node
>> right so instantiate n4 with d4
>> 			# nodes: n0,n1,n2,n3,n4
>>
>> 6. n0.send(d5) 	# toggle n0's downstream pointer "Right"
>> 			# there exists a downstream node right,
>> n1, so send d5 there
>> 			# toggle n1's downstream pointer "Left"
>> 			# in n1 there is no downstream node
>> left so instantiate n5 with d5
>> 			# nodes: n0,n1,n2,n3,n4,n5
>>
>> 7. n0.send(d6)	# So on...
>> 			# ...
>>
>>
>> Any thoughts about how to do this in Python appreciated. Possible at
>> all? Thanks in advance,
>>
>> -Rayme.
>>
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