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From: bzs@BU-CS.BU.EDU (Barry Shein)
Newsgroups: comp.windows.x
Subject: A Call for Callforwards...
Message-ID: <8906292347.AA04479@bu-cs.BU.EDU>
Date: 29 Jun 89 23:47:42 GMT
References: <8906291555.AA02112@LYRE.MIT.EDU>
Sender: daemon@bloom-beacon.MIT.EDU
Organization: The Internet
Lines: 35


Ok, two votes for just use "call_data" (Paul Asente also suggested
this.)

What about the semantics of multiple callbacks supported by
CallCallbacks, does this gibe with passing data back? How is it
coordinated so the call_data isn't stomped on multiple times (ok, the
programmer should just be careful etc, but there is a little bit of
gee why do anything since the user can always write code to simulate
it eventually?)

But I do agree that it might need some more compelling arguments to
bring it from the level of conceptually useful (I think merely
discussing it probably gave some people a useful "aha") to the level
of let's add yet another feature, my sympathy is with you on that.

It also has conceptual roots in CL:

	(member item list :test #'func)

approach to passing the function to ask when the time comes.

In OOP parlance I can't think of a parallel off-hand tho there
probably should be one, basically it's setting an instance variable to
a function pointer tho I'd be hard pressed to find any discourse on
that thought in that sort of literature.

Ah well, something to puncutate the cries for an IBM/PC port of X...

	-Barry Shein

Software Tool & Die, Purveyors to the Trade
1330 Beacon Street, Brookline, MA 02146, (617) 739-0202
Internet: bzs@skuld.std.com
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