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From: dleigh@hplabsz.HPL.HP.COM (Darren Leigh)
Newsgroups: comp.lang.scheme
Subject: Re: OOP in XScheme
Summary: fixed fix
Message-ID: <6109@hplabsz.HPL.HP.COM>
Date: 23 Oct 90 17:53:32 GMT
References: <9010190348.aa28638@mintaka.lcs.mit.edu> <HULTQUIS.90Oct19141650@wk206.nas.nasa.gov>
Reply-To: dleigh@hplabs.UUCP (Darren Leigh)
Organization: Hewlett-Packard Laboratories
Lines: 27

In article <HULTQUIS.90Oct19141650@wk206.nas.nasa.gov> hultquis@nas.nasa.gov writes:

>>>  Subject: xscheme object system bugs and fixes
>
>This patch results in the re-sending of the message to the
>superclass of the class of the object.  This is not very useful.
>
>By changing the zero to a one, the message will be sent
>to the superclass of the class in which the current method was
>defined.  This is surely what was intended.

Jeff is correct here.  I sent out the broken send-super fix and a couple
of days later, someone mailed me some code that that didn't work.  I dug
through the code and discovered the real fix as well.  My face is red.
'Twas hubris on my part to suspect the amazing David Betz of an
abstraction violation rather than a typo.

The send-super fix that does work is what Jeff said:

In xsendsuper() just change:
      cls = getivar(getelement(car(cdr(obj)),0),SUPERCLASS);
to:
      cls = getivar(getelement(car(cdr(obj)),1),SUPERCLASS);

Darren Leigh
dleigh@hplabs.hp.com
hplabs!dleigh