[comp.lang.smalltalk] Questions about ParcPlace ST-80 vs. Eiffel

bruce@menkar.gsfc.nasa.gov (Bruce Mount 572-8408) (03/21/90)

I am investigating the advantages of ParcPlace's Smalltalk-80 versus the 
language Eiffel for a commercial product.  Since my knowledge of ParcPlace's 
Smalltalk is out of date, I would appreciate comments from the net.

Things I already know:

   1.  The Smalltalk libarary of classes is much bigger than the 
       Eiffel library.

   2.  Smalltalk allows arrays elements to contain objects of different
       classes.

   3.  The Smalltalk environment is more sophisticated (browsers, etc.).


Things I want to know:

   1.  Does Smalltalk now support multiple inheritence?  (I had heard
       this was under development a while ago, but I haven't kept up
       to date.)

   2.  Does Smalltalk offer a tool that allows to to create an "executable"
       image?  Yeah, I know that's not really how Smalltalk works but is
       there anything that allows you to automatically reduce your image
       size to the bare minimum once you have a finished product (i.e.
       remove the code for methods that are never used.)

   3.  Any stories (good or bad) about personal experience using both
       Eiffel and Smalltalk.

If you wish to make religious statements about either language please
try to support them with actual examples.  Please reply by e-mail so
we don't start a holy war (if you want a holy war there's currently one 
going on in comp.software-eng).

--Bruce
=================================================
| Bruce Mount                 "Brevity is best" |
| bruce@atria.gsfc.nasa.gov                     |
=================================================

moss@ibis.cs.umass.edu (Eliot Moss) (03/21/90)

May I suggest that you look into Trellis (formerly called Trellis/Owl or just
Owl) from a research group at Digital Equipment? Trellis offers a
Smalltalk-like interactive environment (in some ways I think it is *better*
than the Smalltalk browser and related tools, including a debugger that lets
you set breakpoints, etc.); type-checked, compiled code; and multiple
inheritance (with what I view to be the "right" subtyping rules). It also
sports multiple activities (lightweight pseudo-processes) and exception
handling. It is not a product at this time, but there was a program under
which it could be obtained for use, and I know the group still exists. If
you're interested I suggest you send mail to Patrick O'Brien
(obrien@pbsvax.enet.dec.com). IMHO, Trellis is a better job than Eiffel, and
can be viewed (rooughly speaking) as a type-checked version of Smalltalk with
a clean model of multiple inheritance.				Eliot
--

		J. Eliot B. Moss, Assistant Professor
		Department of Computer and Information Science
		Lederle Graduate Research Center
		University of Massachusetts
		Amherst, MA  01003
		(413) 545-4206; Moss@cs.umass.edu