# [pypy-dev] __builtin__ module

Scott Fenton scott at fenton.baltimore.md.us
Sat Jan 25 00:46:31 CET 2003

```On Fri, Jan 24, 2003 at 03:28:16PM -0800, Bengt Richter wrote:
> [snip]
> I'm thinking "depth" is a monotonic relationship among nodes along a path
> in an acyclic graph, and so far we are talking about two kinds of nodes:
> "interpreter level" and "Python level". I am getting an idea that maybe
> we should be thinking meta-levels instead of two kinds, and that in general
> there can concurrently exist many levels of nodes in the tree, all busily
> acting as "interpreter level" for their higher level parents, except for
> root and leaves. Not sure how useful this is for immediate goals, but I'm
> struggling to form a satisfying abstract view of the whole problem ;-)
> It's interesting that manipulation of representational elements in one
> level implements operations at another level, and manipulation is _defined_
> by a pattern of elements that live somewhere too. It's a subtle soup ;-)

Hmm.... meta-circular interpreters. Sounds suspicously like problems
Lisp has dealt with for years. Perhaps we should take a look at how
systems like Maclisp and Interlisp handled these problems, since they
were themselves written in Lisp, as I recall it. BTW, for
reference I've put a copy of Steele and Sussman's "Art of the Interpreter"
on my site at http://fenton.baltimore.md.us/AIM-453.pdf

parenthetically yours,
-Scott

--
char m[9999],*n[99],*r=m,*p=m+5000,**s=n,d,c;main(){for(read(0,r,4000);c=*r;
r++)c-']'||(d>1||(r=*p?*s:(--s,r)),!d||d--),c-'['||d++||(*++s=r),d||(*p+=c==
'+',*p-=c=='-',p+=c=='>',p-=c=='<',c-'.'||write(1,p,1),c-','||read(2,p,1));}
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: not available
URL: <http://mail.python.org/pipermail/pypy-dev/attachments/20030124/cda1754c/attachment.pgp>
```

More information about the Pypy-dev mailing list