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Article View: comp.lang.functional
Article #566

Re: Is efficient backtracking feasible in functional languages?

#566
From: Joe Armstrong
Date: Wed, 11 Nov 1992 17:17
29 lines
1307 bytes
|> 
|>    strangesucc n =	hd [x|x<-[0..];x>n];
|> 
	....
|> 
|>   - Stream.head(Stream.filter(fn x => x > 1000000,Stream.iota()));
|>   
|>   [Major collection... 21% used (3397260/15733684), 1920 msec]
|>   
|>   [Major collection... 21% used (3397288/15730836), 1910 msec]
|>   
|>   [Major collection... 21% used (3397288/15730948), 1920 msec]
|>   
|>   [Major collection... 21% used (3397288/15730888), 1920 msec]
|>   
|>   [Major collection... 21% used (3397288/15730888), 1910 msec]
|>   val it = 1000001 : int
|>   -

	Wonderfull  !!

	This is the kind of stuff that gives FP a bad name :-)

	Is their a transformation system which can prove that

	strangesucc x == x + 1 ?

	Joe
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Message-ID: <1992Nov11.171742.18783@eua.ericsson.se>
Path: arc1-ca.pugleaf.net!sparky!uunet!mcsun!sunic!sics.se!eua.ericsson.se!erix.ericsson.se!joe
References: <1992Nov10.164456.18062@email.tuwien.ac.at> <TMB.92Nov11104119@arolla.idiap.ch>

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Newsgroups: comp.lang.functional
Path: arc1-ca.pugleaf.net!sparky!uunet!mcsun!sunic!sics.se!eua.ericsson.se!erix.ericsson.se!joe
From: joe@erix.ericsson.se (Joe Armstrong)
Subject: Re: Is efficient backtracking feasible in functional languages?
Message-ID: <1992Nov11.171742.18783@eua.ericsson.se>
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References: <1992Nov10.164456.18062@email.tuwien.ac.at> <TMB.92Nov11104119@arolla.idiap.ch>
Date: Wed, 11 Nov 1992 17:17:42 GMT
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