Path: utzoo!dciem!nrcaer!scs!spl1!laidbak!att!pacbell!ames!killer!pollux!ti-csl!mips!gateley
From: gateley@mips.csc.ti.com (John Gateley)
Newsgroups: comp.lang.scheme
Subject: Re: collect special form for streams
Message-ID: <50694@ti-csl.CSNET>
Date: 3 Jun 88 19:23:56 GMT
Article-I.D.: ti-csl.50694
References: <294@gt-eedsp.UUCP> <50472@ti-csl.CSNET> <748@thalia.rice.edu>
Sender: root@ti-csl.CSNET
Reply-To: gateley@mips.UUCP (John Gateley)
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Organization: TI Computer Science Center, Dallas
Lines: 25

In article <748@thalia.rice.edu> matthias@rice.edu (Matthias Felleisen) writes:
>In article <50472@ti-csl.CSNET> gateley@mips.UUCP (John Gateley) writes:
>>In article <294@gt-eedsp.UUCP> schw@gt-eedsp.UUCP (Dave Schwartz) writes:
>>>How can the "collect" special form for streams (from Chap. 3 of
>>>[...]
>>Extend-syntax's pattern matching is not powerful enough to do this.
>>[...]
>John, what do you think of this one?  
>[Matthias's code deleted]
>
>P.S. Eugene Kohlbecker invented extend-syntax.

Hi Matthias,

As usual you are right and I am wrong. Let me rephrase it a bit:
Extend-syntax is not powerful enough to do it without using help
macros. I can generate the (car (cdr (... tuple))) pattern without
using 'with' or your rebinding of tuple, but I dont think that it
can be done as part of the collect macro without actually changing
the definition of collect. I dont want to rebind tuple because it
changes the pattern matching part of the problem. If you change the
definition, then I think you can do it. Can you prove me wrong this
time?

John