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[Caml-list] yet another question on lazy lists
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Date: 2002-07-08 (00:34)
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,
snail:10/1 Toxteth Rd, Glebe, NSW 2037, Australia.

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