Greetings,
Excerpt from http://theory.lcs.mit.edu/~rivest/sexp.html
---8<---
S-expressions are a data structure for representing complex data. They are
a variation on LISP S-expressions. (Lisp was invented by John McCarthy).
We have adapted S-expressions for use in SDSI and SPKI. The work reported
here is, however, application-independent. (That is, we will use
S-expressions in the SPKI/SDSI work, but have developed it and presented it
in an application-independent manner, so that others may most easily
consider adopting it for other applications.)
[...]
We are currently merging the designs to form SPKI/SDSI 2.0. This design
will use S-expressions as the basic data structure.
---8<---
Has anyone developed a Common Lisp package for encoding and decoding Lisp
Sexprs in this format? The author's examples are all unfortunately in C...
If someone's already done this in CL, and is willing to share, I'd be
grateful for a pointer...
-- Kaelin
From: Fernando Mato Mira
Subject: Re: Implementation of SEXP in Common Lisp?
Date:
Message-ID: <37F4A577.83760604@iname.com>
Kaelin Colclasure wrote:
> Greetings,
>
> Excerpt from http://theory.lcs.mit.edu/~rivest/sexp.html
> Has anyone developed a Common Lisp package for encoding and decoding Lisp
> Sexprs in this format? The author's examples are all unfortunately in C...
> If someone's already done this in CL, and is willing to share, I'd be
> grateful for a pointer...
It does not show up in the shadow directories, or at ietf.org
Expiration date is 4/11/97, so hopefully this has been dumped, as it is
incompatible with the standard CL syntax.
Fernando Mato Mira <········@iname.com> wrote in message
······················@iname.com...
[...]
> It does not show up in the shadow directories, or at ietf.org
> Expiration date is 4/11/97, so hopefully this has been dumped, as it is
> incompatible with the standard CL syntax.
The SEXP document itself has not been moved forward along the RFC track,
but SPKI has -- and SPKI still uses this encoding.
But what do you mean by "incompatible"? Just that the SEXP encoding
cannot be read by the Common Lisp reader? There are fairly pragmatic
reasons for this -- the foremost being that they needed an encoding that
was robust in the presence of the arbitrary introduction of newlines.
Imagine trying to convince the Lisp reader to interpret
(thi
s is
a te
st)
as
(this is a test)
-- Kaelin
From: Fernando Mato Mira
Subject: Re: Implementation of SEXP in Common Lisp?
Date:
Message-ID: <37F4F8D4.1B6C1DE3@iname.com>
Kaelin Colclasure wrote:
> Fernando Mato Mira <········@iname.com> wrote in message
> ······················@iname.com...
> [...]
> > It does not show up in the shadow directories, or at ietf.org
> > Expiration date is 4/11/97, so hopefully this has been dumped, as it is
> > incompatible with the standard CL syntax.
>
> The SEXP document itself has not been moved forward along the RFC track,
> but SPKI has -- and SPKI still uses this encoding.
>
> But what do you mean by "incompatible"? Just that the SEXP encoding
> cannot be read by the Common Lisp reader? There are fairly pragmatic
> reasons for this -- the foremost being that they needed an encoding that
Yes. That's why it should not be promoted as a general purpose format.
From: Christopher R. Barry
Subject: Re: Implementation of SEXP in Common Lisp?
Date:
Message-ID: <87iu4q1904.fsf@2xtreme.net>
"Kaelin Colclasure" <······@everest.com> writes:
> Imagine trying to convince the Lisp reader to interpret
>
> (thi
> s is
> a te
> st)
>
> as
>
> (this is a test)
??? How is any interpreter supposed to determine that the newline
between "s" and "a" is a word boundary while all the other newlines in
your example are supposed to be ignored? Is /usr/dict a component of
whatever you have been talking about?
It is quite trivial to get Lisp, or any language, to give you
(this isa test)
from your example.
Christopher