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[Caml-list] yet another question on lazy lists
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Date: -- (:)
From: John Max Skaller <skaller@o...>
Subject: Re: [Caml-list] yet another question on lazy lists 
>
>
>
>Right again.  This is SICP terminology.  I'll change it if I post any more
>questions on this subject to this list.
>
My understanding is that a list is a finite inductuive type, 
characterised by constructors.
Whereas a stream is like an infinite list, but it is a coinductive type,
characterised by destructors:

    'a list = Empty | Cons of 'a * 'a list
    split ('a stream) -> 'a * 'a stream

As I understand it, the two types are formally dual.
See Charity (if you can find it)  for a language which provides
coinductive types with a natural syntax which makes the duality
syntactically evident.

-- 
John Max Skaller, mailto:skaller@ozemail.com.au
snail:10/1 Toxteth Rd, Glebe, NSW 2037, Australia.
voice:61-2-9660-0850




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