🚀 go-pugleaf

In article <1610.269E1B17@puddle.fidonet.org>
Jason.Kankiewicz@f345.n109.z1.fidonet.org (Jason Kankiewicz) writes:

   Eliot, was Niklaus Wirth himself responsible, in whole or in part, for 
   Modula-3.  Also, when was M3 introduced and what is garbage collection  
   (the deletion of useless variables?)

Wirth was *not* responsible for Modula-3, but he *did* give permission for the
name to be used. (Note, *I* am *not* one of the original developers of
Modula-3, though I have met with a number of the designers and have made
suggestions for future changes (and even gotten one or two minor changes in).)
The history of Modula-3 is related a little bit in the Modula-3 Report
(Revised), and more on a video tape by Jim Donahue (head of the Olivetti
Research Center (now mostly defunct), which participated, along with Digital's
Systems Research Center, in the Modula-3 design effort). I think that a draft
that was in many respects similar to today's Modula-3 was prepared about 2
years ago. The most recent Report was issued last October (PostScript for
which can be ftp'ed from gatekeeper.dec.com, as can the Modula-3 compiler,
etc.; read stuff about the license (which is pretty liberal)).

Garbage collection is the automatic reclamation of unreachable heap allocated
data, i.e., things created by NEW that can no longer be reached by any path of
pointers from global variables or stacks of still existing threads
(processes). If you interpret the words "deletion", "useless", and "variable"
appropriately, then yes, it is "deletion of useless variables", but I would
not describe it that way because "variable" has many different meanings to
different people, because "useless" is a bit imprecise (to me at least), and
because "deletion" is also misleading. Our version of Modula-3 will sport a
generation scavenging type collector, which should run quite fast, essentially
incrementally, and will compact heap space.

I hope this helps your understanding of Modula-3 ..... 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