Common or rare Lisp ?

Reginald S. Perry
Fri, 16 May 1997 12:00:08 -0700

>"Luca" == Luca Pisati <> writes:

> But do not think that ANSI-CL is perferction. It is not.  ANSI
> failed to standardize vital parts of the language as, for instance,
> environments.  Please check in the ANSI specs about it, and you
> would see that environments DO exist in ANSI-CL (and it couldn't be
> otherwise, or you couldn't even compile and load a lisp file), but
> they are absolutely undefined.

[some interesting discussion snipped]

> EQL specializers, which somehow break part of the perfection of the
> CLOS/MOP structure, and force language implementors to do triple
> back flips in order to optimize code.

> flat package system, which creates, yes, namespaces, but only defer
> name conflict to package conflict.

> And what about being able to access compiler information at compile
> time ? My compiler does type inference, so that it can optimize my
> code, but I cannot access that information so that I can optimize
> the way I want (again, missing environments ...).

> And what about MOP ?

Thats a good question. What about the MOP. I have heard some arguments
to eliminate it, but I think that the problem is underexploitation of
the MOP. It seems to me that we could define another metaclass that
gives us static(ish) type semantics. What this would do is allow us to
have fast method access for the low-level stuff or for people who dont
want or need the full-blown MOP but allow everyone else to have the
full power of CLOS if they need it. 

But in order to do this we will have to integrate the MOP in at every
level. Maybe even to the level of being able to alter certain compiler
semantics. If we can do this and document it clearly, I believe that
it would allow everyone from pure speed freaks to complete flexibility
freaks to be able to do what they want with the system.

But you cannot do it halfway. You have to "go for it".


Reginald S. Perry                      e-mail:   
Digital Equipment Corporation
Performance Manager Group	      

My opinions are barely my own. Clearly Digital wants nothing to do with them