From: roconnor@theorem•ca
To: Chris Double <chris.double@double•co.nz>
Cc: bitcoin-development@lists•sourceforge.net
Subject: Re: [Bitcoin-development] Alternative to OP_EVAL
Date: Fri, 30 Dec 2011 12:19:24 -0500 (EST) [thread overview]
Message-ID: <alpine.LRH.2.00.1112301214380.9419@theorem.ca> (raw)
In-Reply-To: <CALn1vHHjY6Qq0zEUcWaNzm_eP_JekjrK26zMXfcrfPSydwSKig@mail.gmail.com>
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On Sat, 31 Dec 2011, Chris Double wrote:
> On Fri, Dec 30, 2011 at 5:42 AM, <roconnor@theorem•ca> wrote:
>> Basically OP_DUP lets you duplicate the code on the stack and that is the
>> key to looping. I'm pretty sure from here we get get Turing completeness.
>> Using the stack operations I expect you can implement the SK-calculus
>> given an OP_EVAL that allows arbitrary depth.
>>
>> OP_EVAL adds dangerously expressive power to the scripting language.
>
> If you look at the archives of the concatenative programming mailing
> list [1] you'll see lots of examples of people creating stack
> languages with minimal operations that exploit similar functionality
> to reduce the required built in operations. The discussion on the list
> is mostly about stack based languages where programs can be pushed on
> the stack and executed (eg. Joy [2]/Factor/Some Forths).
>
> I don't think the scripting engine in bitcoin has the ability to
> concatenate, append or otherwise manipulate scripts on the stack to be
> eval'd though does it?
It will limited ability manipulate scripts on the stack through the use of
arithmetic and hashing operations, and if OP_CAT, OP_SUBSTR and friends
are ever restored, it will have even more abilities.
--
Russell O'Connor <http://r6.ca/>
``All talk about `theft,''' the general counsel of the American Graphophone
Company wrote, ``is the merest claptrap, for there exists no property in
ideas musical, literary or artistic, except as defined by statute.''
next prev parent reply other threads:[~2011-12-30 17:19 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-29 6:55 roconnor
2011-12-29 8:44 ` theymos
2011-12-29 16:42 ` roconnor
2011-12-30 12:01 ` Chris Double
2011-12-30 17:19 ` roconnor [this message]
2012-01-02 15:14 ` Stefan Thomas
2012-01-02 15:59 ` Gavin Andresen
2012-01-02 16:42 ` roconnor
2012-01-02 17:10 ` Stefan Thomas
2011-12-31 9:54 ` Joel Joonatan Kaartinen
2011-12-31 17:28 ` Zell Faze
2011-12-29 16:23 ` Gavin Andresen
2011-12-29 17:01 ` roconnor
2011-12-29 17:06 ` Luke-Jr
2011-12-29 18:00 ` Gavin Andresen
2011-12-29 19:54 ` Stefan Thomas
2011-12-29 19:08 ` Pieter Wuille
2011-12-29 21:00 ` Pieter Wuille
2011-12-29 21:31 ` Alan Reiner
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