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Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!rutgers!gatech!hubcap!billwolf
From: billwolf@hubcap.clemson.edu (William Thomas Wolfe,2847,)
Newsgroups: comp.lang.ada
Subject: Re: Garbage Collection
Message-ID: <3848@hubcap.UUCP>
Date: 12 Dec 88 18:19:13 GMT
References: <65475@ti-csl.CSNET>
Sender: news@hubcap.UUCP
Reply-To: wtwolfe@hubcap.clemson.edu
List-Id: <comp.lang.ada>

>From article <65475@ti-csl.CSNET>, by gateley@m2.csc.ti.com (John Gateley):
>>   Also, I disagree with the claim that a lot of effort is involved;
>>   in my experience, DESTROY routines are among the easiest to code.
>>   Usually, the ADT is defined recursively, lending itself to a very
>>   easy recursive destruction procedure; [...]
> 
> This method is fine, as long as no structures are shared. [...] 
> [...] if your programming style never uses shared structure, then you
> don't need GC. 

    Precisely.  

    Structural sharing is nothing more than a euphemism for hacking.  
    It is the spatial equivalent of what hackers enjoy doing with time 
    in the name of efficiency, in their unmitigated zeal to violate every
    form of abstraction, to throw all traces of readability and reliability 
    to the winds.  

    If GC were prohibited, it would infuriate all those who enjoy hacking
    with space as opposed to time.  Good.  Let them use C.  Ada is the
    language of those who appreciate that "abstraction is the fundamental
    tool with which complexity can be effectively managed", and recognize
    that to violate an abstraction (rather than design another which is
    more appropriate to their needs) is to be penny wise but pound foolish.

    Folks, space management in Ada is NOT that difficult.  I had problems with
    space management in Pascal, but Ada-based ADTs have basically made it
    into a non-issue.  The real challenges which remain are problems which
    are inherent in the language itself, such as getting local ADTs to be 
    properly destroyed as an automatic consequence of a block exit.

    I agree that existing tools for detecting space-wasting ADTs are 
    inadequate, but let's call for better debugging tools rather than
    going about advocating the practice of spewing garbage. 


    
                                        Bill Wolfe

                                 wtwolfe@hubcap.clemson.edu