Wade Hennessey's work on lisp

[<serafini@ra-iris9.arc.nasa.gov>]

   From: layer@franz.com (Kevin Layer)
   Date: Wed, 02 Dec 92 10:16:11 -0800

   >> I picked up Hennessey's paper (described in included message below)
   >> and found it quite convincing. I'd like to know what people at Franz
   >> think of this work and if acl is moving in this direction.

   We have been looking at shared library technology since it was
   introduced on various platforms, and will be giving more thought to
   the incorporation of it into a future version of Allegro CL.

   As you know, there is a trade off between the ability to share
   portions of an image among many processes and the cost of initializing
   an image to link in the shared libraries and create the per-process
   data.  Lisp, unlike C, has a large dynamic component.  For example,
   the symbols made available by a shared library need to be interned.
   It is unclear what the startup cost of an executable would be for a
   fully compliant ANSI Common Lisp (ie, one that includes CLOS).

But, since the purpose of a shared-library lisp is to reduce application
size, couldn't you have some kind of compiler/optimizer that would only 
intern the symbols that were used in the application?  I assmue this would
radically reduce the number of symbols needed, and maybe make startup 
faster.  I know this approach has been used to reduce image sizes by 
removing unneeded code.

-David

   Kevin Layer, Franz Inc.         1995 University Avenue, Suite 275
   layer@Franz.COM (internet)      Berkeley, CA  94704  USA
   Phone: (510) 548-3600           FAX: (510) 548-8253