[Info-vax] Intel proposal to simplify x86-64

[Johnny Billquist]

On 2023-06-10 14:18, Dan Cross wrote:
> In article <u61md6$49j$1 at panix2.panix.com>,
> Scott Dorsey <kludge at panix.com> wrote:
>> Dan Cross <cross at spitfire.i.gajendra.net> wrote:
>>> Believe it or not, `sed` is actually Turing complete; I imagine
>>> that TECO is as well.  So in some absolute sense, both are
>>> equally powerful.
>>
>> If that were the case, one could write some yacc code to turn sed scripts
>> into teco scripts.  This may hurt your brain.
> 
> I don't know if yacc would be the best tool for that, but yeah,
> it sounds very doable.  It'd be an interesting hack, if nothing
> else.

It would just be pure, utter madness. But for sure, very doable.
yacc is a tool for writing compilers, but I'm almost suspecting it's a 
bit of overkill in this case, and might make for a more complex solution 
in the end.

But sed to teco seems a somewhat simple problem. Teco to sed could be 
much more complicated, I think. Not sure if it would actually be 
possible. Turing complete does not tell the full picture. Specifically I 
wonder about some OS interactions and system call stuff. In teco you 
can, for instance, read and act on individual input characters, 
unrelated to the file you are operating on, and turn off and on 
character echo, for example. I have no idea if this can even be 
accomplished in sed.

   Johnny