Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!uunet!samsung!usc!snorkelwacker!bu.edu!xylogics!transfer!lectroid!jjmhome!m2c!umvlsi!dime!dime.cs.umass.edu!moss From: moss@cs.umass.edu (Eliot Moss) Newsgroups: comp.lang.smalltalk Subject: Re: Why SYMBOLS? Message-ID: Date: 11 Apr 90 19:21:01 GMT References: <16286@estelle.udel.EDU> Sender: news@dime.cs.umass.edu Reply-To: moss@cs.umass.edu Distribution: na Organization: Dept of Comp and Info Sci, Univ of Mass (Amherst) Lines: 19 In-reply-to: new@udel.EDU's message of 9 Apr 90 18:50:37 GMT There is not really any nice way to get rid of the symbols ... they are being held onto by the symbol table, which is used to make *sure* that each symbol always has the same unique object id within a given Smalltalk image. Some cloners have the ability to discard symbols that are referred to *only* from the symbol table, but I am not sure the standard cloner does that. One would need a new concept (e.g., what some people call *weak pointers*, which continue to point to an object so long as any ordinary pointers do, but turns into nil at a gc that finds there are no longer any ordinary pointers to the same object). The complexity was perhaps judged not to be worth the benefit for typical uses of the system, though that may be cold comfort in your case! 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